Risk Factors and Prediction Model for Spontaneous Pneumothorax Recurrence: A Retrospective Study of 440 Patients

Risk Factors and Prediction Model for Spontaneous Pneumothorax Recurrence: A Retrospective Study of 440 Patients | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Risk Factors and Prediction Model for Spontaneous Pneumothorax Recurrence: A Retrospective Study of 440 Patients Qingcai Lin, Jiehuan Lin, Jun Ma This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7322540/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 11 You are reading this latest preprint version Abstract Background Spontaneous pneumothorax (SP) recurrence imposes substantial clinical burdens, yet long-term risk stratification remains poorly defined. Methods This retrospective cohort study analyzed 440 SP patients treated at Longyan First Hospital (2010–2020). Multivariable logistic regression and Cox proportional hazards models identified recurrence predictors, with high-resolution computed tomography quantification of bullae characteristics (diameter/number). Model performance was evaluated using receiver operating characteristic curves. Results The 5-year recurrence rate was 31.82% (140/440), with 75.71% occurring within 1 year. Key independent risk factors: Secondary spontaneous pneumothorax (SSP vs. primary spontaneous pneumothorax[PSP]: adjusted odds ratio [aOR], 2.91; 95% confidence interval [CI], 1.47–5.76); Smoking ≥ 5 pack-years (aOR, 3.28; P 5 cm (adjusted hazard ratio [aHR], 1.77; 95% CI, 0.48–6.56) or > 5 in number (aHR, 7.01; 95% CI, 1.81–27.19); Surgical intervention (video-assisted thoracoscopic surgery [VATS] bullectomy with pleurodesis) reduced recurrence risk by 88% (aOR, 0.13; 95% CI, 0.04–0.42) versus conservative management. The prediction model integrating bullae morphology demonstrated significantly improved discrimination (area under the curve (AUC) = 0.832 vs. 0.797; ΔAUC = + 0.035, P = 0.001). Conclusions SSP, smoking, and bullae burden (> 5 lesions or > 5 cm diameter) are potent predictors of SP recurrence. VATS bullectomy with pleurodesis significantly mitigates risk. Quantification of bullae morphology enhances prediction accuracy, supporting its integration into risk-stratified clinical protocols to guide surgical decision-making. Spontaneous pneumothorax Recurrence risk factors Pulmonary bullae burden Video-assisted thoracoscopic surgery Prediction model Secondary spontaneous pneumothorax Figures Figure 1 Background Spontaneous pneumothorax (SP) represents a significant respiratory condition characterized by the accumulation of air in the pleural space without preceding trauma. It is classified into primary spontaneous pneumothorax (PSP) and secondary spontaneous pneumothorax (SSP) based on the presence or absence of underlying pulmonary diseases (particularly chronic obstructive pulmonary disease (COPD) and alveolar structural abnormalities). Conservative management yields recurrence rates of 20% at 1 year and 35% at 5 years, while SSP shows higher rates of 54% (1 year) and 70% (5 years).[ 1 , 2 ] These recurrence dynamics indicate persistent risk beyond the immediate post-treatment period, necessitating long-term monitoring strategies. The clinical burden of recurrence is considerable, often requiring repeated interventions, extended hospitalization, and impairing significant quality-of-life impairment for affected individuals.[ 3 – 6 ] The risk of SP recurrence may be influenced by a variety of factors, such as age, sex, body mass index (BMI), smoking history, pneumothorax type, pulmonary bullae status, treatment modality.[ 1 , 4 , 7 – 10 ] Our findings align with existing literature showing that patients with SSP have a significantly higher recurrence risk than those with PSP, likely attributable to underlying pulmonary pathologies.[ 11 , 12 ] In addition, the coexistence of pulmonary bullae is an independent predictor of recurrence[ 13 – 16 ]. Surgical intervention (video-assisted thoracoscopic surgery (VATS) bullectomy with pleurodesis) reduces recurrence rates to < 5%.[ 10 , 17 ] However, prior studies are limited by follow-up durations shorter than 5 years, which may lead to underestimation of the recurrence rate, inconsistent conclusions on the risk factors of recurrence, and lack of unified standards and digital measurement indicators for the prediction of recurrence risk.[ 7 , 16 , 18 ] Meta-analysis with larger samplesalso failed to unify the morphological characteristics of pulmonary bullae. [ 4 , 7 , 19 ] This retrospective cohort study of 440 patients aimed to quantify recurrence patterns and identify predictors of disease recurrence. The recurrence risk stratification emerging from our analysis provides clinicians with valuable prognostic information and underscores the need for personalized management approaches based on individual risk profiles. Early identification of recurrence risk factors is critical for guiding preventive interventions. Methods Study Design and Data Source We conducted a retrospective analysis of 486 patients hospitalized with SP at Longyan First Hospital (January 2010-May 2020). After applying exclusion criteria, we enrolled 440 patients (exclusion rate: 9.5%). Inclusion criteria: (1) Initial diagnosis of SP;(2)Treatment with one of the following approaches: Conservative management; Surgical intervention (VATS bullectomy with pleurodesis); Needle aspiration (NA)/ Chest tube drainage (CTD) . Exclusion criteria: (1) Previous diagnosis of SP; (2) Traumatic or iatrogenic pneumothorax; (3) Treatment with bronchoscopic occlusion therapy; (4) Persistent air leak at discharge; (5) Comorbid severe cardiopulmonary dysfunction or multiorgan failure; (6) Incomplete follow-up data (lost to follow-up or follow-up duration <5 years). We retrospectively collected baseline characteristics including age, sex, and smoking history (quantified in pack-years) and clinical features (pneumothorax type [PSP/SSP], laterality, lung collapse volume, treatment modality, and presence/ number/maximum diameter of pulmonary bullae). Standardized telephone follow-ups were conducted at 1, 2, and 5 years post-discharge to assess recurrence, with confirmation by chest computed tomography (CT). For confirmed recurrences, we documented time to first recurrence, laterality, and subsequent treatments. Statistical Analyses Continuous normally distributed variables were expressed as mean ± standard deviation ( ±SD); categorical variables as frequencies (percentages). Intergroup comparisons used chi-square tests or Fisher’s exact tests. Univariable and multivariable logistic regression identified independent recurrence risk factors. Variables significant ( P < 0.05) in univariable analysis were included in the multivariable model. Predictive performance was evaluated using receiver operating characteristic (ROC) curve analysis (area under the curve [AUC]). Cox proportional hazards regression estimated hazard ratios and 95% confidence intervals (CIs) for time-to-event analysis. Kaplan-Meier survival curves illustrated recurrence-free probability (log-rank tests for group differences). Analyses used the Social Sciences (SPSS) version 29.0 (International Business Machines [IBM] Corp, Armonk, NY); P < 0.05 (two-tailed) indicated statistical significance. Results Baseline Characteristics and Clinical Features The study enrolled 440 patients with SP (87.73% male) with a mean age of 41.17 ± 21.62 years, as shown in Table 1 . Age-related disparities existed in treatment patterns and subtypes: Among 266 patients aged < 50 years, 68.05% underwent surgery (VATS bullectomy with pleurodesis), 24.06% NA/CTD, and 7.89% conservative management; PSP predominated (PSP:SSP = 52.20:1). Among 174 patients aged ≥ 50 years, 77.01% received NA/CTD, 22.41% surgery, and 0.57% conservative management; SSP predominated (PSP:SSP = 0.63:1). Preoperative chest CT identified pulmonary bullae in 260 patients (70.27%); surgical exploration revealed an additional 110 non-measurable bullae (diameter < 1 cm; number = 1–3). Table 1 is placed after the references. Table 1 Characteristics of Patients With Spontaneous Pneumothorax(SP): Recurrence vs. Non-Recurrence Groups Characteristics Recurrence Group n = 140 Non-recurrence Group n = 300 P value Sex 0.32 Male 126(90.00%) 260(86.67%) Female 14(10.00%) 40(13.33%) Age < 0.001 <50 years old 48(34.29%) 218(72.67%) ≥50 years old 92(65.71%) 82(27.33%) Smoking history < 0.001 <5 pack-years 52(37.14%) 193(64.33%) ≥5 pack-years 88(62.86%) 107(35.67%) Pneumothorax type < 0.001 PSP 65(46.43%) 264(88.00%) SSP 75(53.57%) 36(12.00%) The laterality of SP 0.52 Left 60(42.86%) 145(48.33%) Right 79(56.43%) 151(50.33%) Bilateral 1(0.71%) 4(1.33%) Treatment modality < 0.001 Conservative management 8(5.71%) 14(4.67%) Surgical intervention 30(21.43%) 190(63.33%) NA/CTD 102(72.86%) 96(32.00%) Pulmonary bullae status 0.02 Bullae-absent 14(10.00%) 56(18.67%) Bullae-present 126(90.00%) 244(81.33%) Maximum bullae diameter < 0.001 Absent 26(18.57%) 154(51.33%) Small ( 5 cm) 29(20.71%) 9(3.00%) Number of bullae 5 63(45.00%) 28(9.33%) Degree of lung collapse volume 0.24 <50% 78(55.71%) 185(61.67%) ≥50% 62(44.29%) 115(38.33%) Data are presented as n (%). Abbreviations: SP, Spontaneous pneumothorax; PSP, Primary spontaneous pneumothorax; SSP, Secondary spontaneous pneumothorax; NA, Nneedle aspiration; CTD, Chest tube drainage. a Categorical variables were analyzed using chi-square test and Fisher's exact test. Follow-up Outcomes All 440 patients completed 1-, 2-, and 5-year follow-ups (0% lost). The 5-year recurrence rate was 31.82% (140/440). Most recurrences (75.71%) occurred within the first year. There were 13 cases recurrence within 1–2 years, and 21 cases within 2–5 years. Recurrences showed significant right-sided predominance (60.00% right [84/140] vs 39.29% left [55/140], 0.71% bilateral [1/140]). NA/CTD was used in 69.29% of cases (97/140), while surgical intervention was required in 25.00% (35/140), and conservative management in only 5.7% (8/140). Univariable analysis Significant recurrence predictors ( P 5 cm), and higher bullae number (> 5). Surgical intervention reduced risk ( P 0.05). Multivariable analysis After adjusting for age and smoking history(Table 2 ), the initial logistic regression model demonstrated that SSP (adjusted odds ratio [aOR], 3.64; 95% CI, 2.06–6.42) and bullae presence (aOR, 4.09; 95% CI, 1.97–8.47) increased risk, while surgical intervention was protective (aOR, 0.12; 95% CI, 0.04–0.35) in Model 1. Subsequent refinement incorporating bullae morphology revealed a strong dose-response relationship in Model 2. Both lager bullae diameter (> 5cm; aOR, 1.77; 95% CI, 0.48–6.56) and higher bullae number (> 5; aOR, 7.01; 95% CI, 1.81–27.19) independently predicted higher recurrence risk( P = 0.003, P = 0.033). Notably, surgical intervention maintained its protective effect (aOR, 0.13; 95% CI, 0.04–0.42) across both models, while conservative management and NA/CTD showed consistently higher recurrence rates. Table 2 is placed after the references. Table 2 Sequential Logistic Regression Models for SP Recurrence Model 1 Model 2 Variable Category β (SE) aOR (95% CI) P value β (SE) aOR (95% CI) P value Pneumothorax type SSP (ref: PSP) 1.291 (0.29) 3.64 (2.06–6.42) < 0.001 1.068 (0.35) 2.91 (1.47–5.76) 0.002 Treatment modality Surgical intervention (ref: Conservative management) -2.134 (0.55) 0.12 (0.04–0.35) < 0.001 -2.047 (0.60) 0.13 (0.04–0.42) < 0.001 NA/CTD -0.329 (0.52) 0.72 (0.26–2.01) 0.53 -0.305 (0.54) 0.74 (0.26–2.13) 0.574 Bullae characteristics Presence Present (ref: Absent) 1.408 (0.37) 4.09 (1.97–8.47) < 0.001 - - Maximum bullae diameter Small ( 5 cm) - - 0.571 (0.67) 1.77 (0.48–6.56) 0.393 Number of bullae 1–2 (ref: 0) - - 1.120 (0.55) 3.07 (1.04–9.02) 0.042 3–5 - - 1.270 (0.66) 3.56 (0.98–12.94) 0.054 >5 - - 1.947 (0.69) 7.01 (1.81–27.19) 0.005 Model 1: Demographic and clinical factors, adjusted for: age and smoking history; Model 2: Model 1 + Morphological characteristics of pulmonary bullae, adjusted for: age and smoking history. Abbreviations: AOR, Adjusted odds ratio; CI, Confidence interval; Ref, Reference; SE, Standard error; AUC, Area under the curve. a P -values derived from multivariable logistic regression. The models demonstrated good predictive performance with AUC values of 0.797 (95% CI, 0.749–0.844, P < 0.001) for Model 1 and 0.832 (95% CI, 0.790–0.874, P < 0.001) for Model 2, indicating clinically useful discrimination (ΔAUC = + 0.035, P = 0.001, DeLong's test). Cox Regression Analysis In the survival analysis models excluding non-significant confounders, both the Score test (Model 1 adjusted for age, sex and smoking history, 147.37, P < 0.001; Model 2 adjusted for age, sex, smoking history and number of bullae, 153.49, P < 0.001 ) and likelihood ratio test (Model 1: χ² =121.96, P < 0.001; Model 2: χ² =130.70, P < 0.001) confirmed the overall significance of predictors for pneumothorax recurrence. In Model 1, SSP (adjusted hazard ratio [aHR], 2.30; 95% CI, 1.53–3.47) and bullae presence (aHR = 2.85, 95% CI:1.56–5.22) significantly increased the risk of recurrence, and surgical intervention (aHR, 0.20; 95% CI, 0.09–0.45) significantly reduced the risk of recurrence (Table 3 ). In Model 2, the findings remained consistent with the univariate results (Model 1): SSP maintained its significant association with increased recurrence risk (aHR, 2.37; 95% CI, 1.55–3.62), while surgical intervention continued to demonstrate a protective effect (aHR, 0.30; 95% CI, 0.14–0.67). The log-rank test was subsequently applied to evaluate the impact of bullae number. Table 3 is placed after the references. Table 3 Cox Regression Analysis for SP Recurrence Model 1 Model 2 Variable Category aHR (95% CI) P value a HR (95% CI) P value Pneumothorax type SSP (ref: PSP) 2.30 (1.53–3.47) < 0.001 2.37 (1.55–3.62) < 0.001 Treatment modality Surgical intervention (ref: Conservative management) 0.20 (0.09–0.45) < 0.001 0.30 (0.14–0.67) 0.003 NA/CTD 0.85 (0.40–1.82) 0.675 0.93 (0.44–1.98) 0.848 Bullae characteristics Presence Present (ref: Absent) 2.85 (1.56–5.22) < 0.001 - Maximum bullae diameter Small (< 1 cm) (ref: Absent) - - 0.30 (0.17–0.56) 5 cm) - - 0.54 (0.34–0.83) 0.006 Model 1: adjusted for: sex, age, and smoking history; Model 2: adjusted for: sex, age, smoking history and number of bullae. Abbreviations: AHR, Adjusted hazard ratio. Conservative management vs. Surgical intervention, χ 2 = 7.851, P = 0.005; Conservative management vs. NA/CTD, χ 2 = 2.010, P = 0.156; Surgical intervention vs. NA/CTD, χ 2 = 71.971, P < 0.001. Absent vs. <1 cm, χ 2 = 17.627, P < 0.001; Absent vs. 1–5 cm, χ 2 = 25.046, P 5 cm, χ 2 = 89.694, P < 0.001; <1 cm vs. 1–5 cm, χ 2 = 0.120, P = 0.729; 5 cm, χ 2 = 11.723, P 5 cm, χ 2 = 24.368, P < 0.001. Kaplan-Meier Survival Analysis Recurrence-free survival (RFS) was assessed using Kaplan-Meier analysis, stratified by treatment modality, pneumothorax type and pulmonary bullae characteristics (Fig. 1 ). Restricted mean survival time (RMST) was calculated with a 60-month truncation time point due to limited follow-up duration. Significant differences in RFS were observed based on bullae size (Fig. 1 , Table 4 ). Patients with small bullae ( 0.05 vs. small bullae). In contrast, large bullae (> 5 cm) were associated with significantly shorter RFS (RMST₆₀ = 21.96 months; 95% CI, 14.03–29.89; P < 0.001 vs. small and medium bullae). Figure 1 and Table 4 are placed after the references. Table 4 Restricted Mean Survival Time (RMST) for SP Recurrence by Bullae Morphological Characteristics Characteristic Category RMST₆₀ (months) 95% CI Maximum bullae diameter Absent 52.86 50.12–55.60 Small ( 5 cm) 21.96 14.03–29.89 Number of bullae 0 50.73 45.70-55.76 1–2 51.28 48.52–54.03 3–5 40.52 34.80-46.24 > 5 25.44 20.11–30.78 RMST was evaluated with a 60-month truncation time point owing to limited follow-up duration. Detailed pairwise log-rank comparisons for all parameters are presented in Fig. 1 -D and Fig. 1 -E, with corresponding χ 2 values and adjusted P -values. All tests accounted for multiple comparisons using the Bonferroni method. Abbreviations: RMST, Restricted mean survival time. A significant dose-dependent relationship was observed between bullae number and recurrence risk ( P < 0.001 for trend). Patients with 1–3 bullae exhibited the longest RFS (RMST₆₀ = 51.28 months; 95% CI, 48.52–54.03). Those with 3–5 bullae showed intermediate outcomes (RMST₆₀ = 40.52 months; 95% CI, 34.80-46.24; P 5 bullae had the poorest prognosis (RMST₆₀ = 25.44 months; 95% CI, 20.11–30.78; P < 0.001 vs. 3–5 bullae), confirming bullae quantity as a critical determinant of recurrence. Discussion This retrospective study of 440 patients with SP advances the understanding of recurrence dynamics through three pivotal contributions: (1) implementation of a standardized 5-year follow-up protocol that improved recurrence detection by 15% compared to conventional 2-year observations; (2) development of an integrated predictive framework combining multivariate statistical methods; and (3) high-resolution CT quantification of bullae morphology. Our findings confirm the persistent burden of SP recurrence (31.82% at 5 years), with 75.71% occurring within the first year, underscoring the need for risk-stratified management. Validated and Novel Risk Factors The significant difference in recurrence rates between PSP and SSP (19.8% [65/329] vs. 67.6% [75/111]; P < 0.001) aligns with established literature attributing SSP's elevated risk to comorbid pulmonary pathologies such as COPD.[ 11 , 20 ] Multivariable analysis confirmed SSP as an independent predictor (aOR, 2.91; 95% CI, 1.47–5.76), likely due to compromised lung integrity. Smoking ≥ 5 pack-years significantly increased risk ( P < 0.001), consistent with evidence linking tobacco use to parenchymal destruction and bullae formation.[ 8 ] These findings corroborate existing evidence and reinforce the imperative for smoking cessation and aggressive management of comorbid respiratory conditions in patients with SP. [ 6 , 10 ] A key innovation of this study is the granular quantification of bullae morphology. Bullae presence alone increased recurrence risk 4.09-fold (95% CI, 1.97–8.47). Our models revealed a dose-response relationship: patients with > 5 bullae faced a 7.01-fold elevated risk (95% CI:1.81–27.19), and those with large bullae (> 5 cm) had significantly shorter RFS (RMST₆₀ = 21.96 months; 95% CI, 14.03–29.89; P < 0.001 vs. small and medium bullae). This morphologic stratification addresses a critical gap in prior meta-analyses that failed to unify bullae characteristics, providing clinicians with actionable thresholds for risk assessment. Treatment Modalities and Age Disparities Surgical intervention (VATS bullectomy with pleurodesis) reduced recurrence risk by 88% (aOR, 0.13; 95% CI, 0.04–0.42) compared to conservative management, demonstrating its efficacy in achieving pleural adhesion and bullae resection. Conversely, non-surgical approaches (NA/CTD) were associated with recurrence rates exceeding 51.51%(102/198), highlighting non-surgical approaches role as bridging therapies rather than definitive solutions. Notably, we observed a stark age-related treatment disparity: A higher proportion of younger patients underwent surgery (68.05% of those aged < 50 years), while older cohorts received NA/CTD (77.01% of those aged ≥ 50 years). This likely reflects clinical hesitancy to operate on older patients with comorbidities, despite SSP’s predominance in this group. Our data suggest that age alone should not preclude surgical evaluation, as high-risk SSP patients are likely to benefit from individualized risk-benefit assessments. Conservative management is a safe and viable option for low-risk primary spontaneous pneumothorax (PSP) patients, potentially avoiding the procedural risks associated with NA or CTD.[ 3 , 6 , 21 ] Mechanistic Insights from Statistical Modeling Our integrated predictive framework elucidated the complex mechanisms of SP recurrence through complementary statistical approaches: (1) Unadjusted associations (Chi-square/Fisher’s tests): Identified age, smoking, pneumothorax type, treatment modality, and bullae characteristics as potential risk factors; (2) Logistic regression (5-year risk): After adjusting for confounders, pneumothorax type, treatment modality, and bullae presence remained significant. Notably, bullae number (> 5) dominated short-term risk (aOR, 7.01), suggesting acute mechanical rupture from multiple vulnerable sites; (3) Cox regression (time-to-event): Confirmed SSP (aHR, 2.37), surgical protection (aHR, 0.30), and bullae presence as long-term risks. Intriguingly, only bullae diameter (> 5 cm) persisted as a chronic predictor (aHR, 0.54; P = 0.006), likely reflecting progressive alveolar damage and pleural instability. Kaplan-Meier analysis: Log-rank tests confirmed the prognostic value of bullae morphology but highlighted the method’s limitation in multivariate adjustment. These results reveal a dual-phase recurrence mechanism: (1) Acute phase (≤ 1 year): Driven by bullae number, where multiple lesions increase rupture probability; (2) Chronic phase (1–5 years): Governed by bullae size, with large (> 5 cm) lesions predisposing to recurrent alveolar damage. Clinical Implications Our prediction model (Model 2 AUC = 0.832) effectively stratifies recurrence risk. High-risk patients (SSP, smokers, > 5 bullae, or bullae > 5 cm) should receive intensified monitoring (quarterly clinical/CT follow-up for 1 year) and early surgical evaluation, while low-risk PSP patients may be managed conservatively. The statistically significant improvement in predictive accuracy from bullae quantification (ΔAUC = + 0.035, P = 0.001) strongly supports the routine incorporation of high-resolution CT bullae characterization into standard risk assessment protocols. Limitations and Future Directions While this study benefits from rigorous 5-year follow-up, limitations include its single-center retrospective design and potential selection bias. Longer observation may reveal additional late recurrences. Although we standardized bullae measurements (including subcentimeter lesions detected intraoperatively), interobserver variability in CT interpretation warrants consideration. Genetic predispositions (e.g., FLCN mutations[ 22 , 23 ]) were not evaluated but merit investigation in future prospective studies. Conclusions SSP, smoking, and pulmonary bullae (> 5 cm or > 5 lesions) are key predictors of SP recurrence. VATS bullectomy with pleurodesis significantly reduces recurrence risk and should be prioritized in high-risk patients. Our dual-phase mechanistic model (acute mechanical vs. chronic progressive) underscores the need for stage-specific management: early intervention for patients with multiple bullae and long-term surveillance for those with large bullae. Abbreviations AHR Adjusted Hazard Ratio AOR Adjusted Odds Ratio AUC Area Under The Curve BMI Body Mass Index CI Confidence Interval COPD Chronic Obstructive Pulmonary Disease CT Computed Tomography CTD Chest Tube Drainage IBM International Business Machines NA Needle Aspiration PSP Primary Spontaneous Pneumothorax RFS Recurrence-Free Survival RMST Restricted Mean Survival Time ROC Receiver Operating Characteristic SD Standard Deviation SP Spontaneous Pneumothorax SSP Secondary Spontaneous Pneumothorax VATS Video-Asisted Thoracoscopic Surgery Declarations Correspondence to: Qingcai Lin, MM; email: [email protected] Ethics approval and consent to participate This study was approved by the Institutional Review Board of the Ethics Committee of Longyan First Hospital (Approval No.: LYREC2025-K144-01). Patient consent was waived due to the retrospective nature of the study. Consent for publication Not applicable. Availability of data and materials The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request. Competing interests The authors declare no competing interests. Funding No external funding was received. Authors' contributions Q.C.Lin had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis, including and especially any adverse effects. J.H.Lin and J.Ma contributed substantially to the study design, data analysis and interpretation, and the writing of the manuscript. All authors approved the final version for submission. Acknowledgements The authors thank the Department of Thoracic Surgery at Longyan First Hospital for their clinical support. Authors' information Department of Thoracic Surgery (Q.C. Lin., J.H.Lin., and J.Ma.), Longyan First Hospital, Longyan, Fujian, China. 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Video-Assisted Thoracic Surgery (VATS) Talc Pleurodesis Versus Pleurectomy for Primary Spontaneous Pneumothorax: A Large Single-Centre Study with No Conversion. World J Surg. 2019;43(8) :2099–105. https://doi.org/10.1007/s00268-019-05001-2. Nonomura R, Yabe R, Oshima Y, Sasaki T, Ishibashi N, Sugawara T. Post-surgery spontaneous pneumothorax: Long-term recurrence rates and follow-up challenges revealed by a written survey. PloS One. 2024;19(10) :e0307910. https://doi.org/10.1371/journal.pone.0307910. Hung CS, Chen YC, Yang TF, Huang FH. Systematic review and meta-analysis on juvenile primary spontaneous pneumothorax: Conservative or surgical approach first? PloS One. 2021;16(4) :e0250929. https://doi.org/10.1371/journal.pone.0250929. Wang Y, Abougergi MS, Li S, Kazmierski D, Patel P, Sharma N, et al. Recurrence Prophylaxis in Secondary Spontaneous Pneumothorax: A Nationwide Readmission Database Analysis. Chest. 2020;158(6) :2474–84. https://doi.org/10.1016/j.chest.2020.06.032. Smyth R, Shojaee S, Feller-Kopman D. Primary Spontaneous Pneumothorax. N Engl J Med. 2024;390(7) :666–8. https://doi.org/10.1056/NEJMclde2311176. Hawkins P, Logan PM, Reeves EP, McElvaney NG. Pneumothorax and lung cysts: a family affair. Lancet Lond Engl. 2019;393(10191) :2635. https://doi.org/10.1016/S0140-6736(19)31283-8. Sattler EC, Syunyaeva Z, Mansmann U, Steinlein OK. Genetic Risk Factors for Spontaneous Pneumothorax in Birt-Hogg-Dubé Syndrome. Chest. 2020;157(5) :1199–206. https://doi.org/10.1016/j.chest.2019.12.019. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviews received at journal 06 Apr, 2026 Reviews received at journal 30 Mar, 2026 Reviewers agreed at journal 27 Mar, 2026 Reviewers agreed at journal 25 Mar, 2026 Reviews received at journal 07 Sep, 2025 Reviewers agreed at journal 04 Sep, 2025 Reviewers invited by journal 04 Sep, 2025 Editor invited by journal 01 Sep, 2025 Editor assigned by journal 29 Aug, 2025 Submission checks completed at journal 29 Aug, 2025 First submitted to journal 07 Aug, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7322540","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":497416897,"identity":"c9047af6-d8ea-4590-bdcd-872282b453bb","order_by":0,"name":"Qingcai Lin","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA90lEQVRIiWNgGAWjYBACA4n8bxIPDBgY2CBcGyDB3MDAcACflhw2iQSEljQgi5GAFp4zQC0I/mEitLD3ALUU3JHtk26/+OFHwXk5g/uNjQ8+nGGQ5xfDrs+Amf/4jwSDZ8ZtMmeKJXsMbhsbHGNsNpxxg8Fw5uwEHFp4QH45nNgmkZPGwGNwO3HDMcY2aZ4PDAkGt4nQwvjH4BxJWtKPMfMYHIBquUFYizHQFmZpGYNkY8ljiUC/nJHA6Rf7ZqCWD38Oy86fkf7w45s/dnJ8hw8ffPDhmI08vzR2LTAAjAseA2QBCbzKoVrYHxBUNQpGwSgYBSMTAAApgl6BlxFFKgAAAABJRU5ErkJggg==","orcid":"","institution":"Longyan First Hospital","correspondingAuthor":true,"prefix":"","firstName":"Qingcai","middleName":"","lastName":"Lin","suffix":""},{"id":497416898,"identity":"e240eed0-eca2-44ff-86b7-c192941b2096","order_by":1,"name":"Jiehuan Lin","email":"","orcid":"","institution":"Longyan First Hospital","correspondingAuthor":false,"prefix":"","firstName":"Jiehuan","middleName":"","lastName":"Lin","suffix":""},{"id":497416899,"identity":"a97ab221-3424-4a61-9201-4f84a111819a","order_by":2,"name":"Jun Ma","email":"","orcid":"","institution":"Longyan First Hospital","correspondingAuthor":false,"prefix":"","firstName":"Jun","middleName":"","lastName":"Ma","suffix":""}],"badges":[],"createdAt":"2025-08-08 01:53:16","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7322540/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7322540/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":89386602,"identity":"cf7103bd-ac3a-447a-8a01-4a07e2608310","added_by":"auto","created_at":"2025-08-19 12:36:15","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":307788,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eA-E, Kaplan-Meier Analyses of SP Recurrence stratified by: (A) treatment modality; (B) bullae status; (C) pneumothorax type; (D) bullae diameter; (E) bullae number.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA: conservative management vs. surgical intervention, \u003cem\u003eχ\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e=7.851, \u003cem\u003eP \u003c/em\u003e= 0.005; conservative management vs. NA/CTD \u003cem\u003eχ\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e=2.010, \u003cem\u003eP \u003c/em\u003e= 0.156; surgical intervention vs. NA/CTD \u003cem\u003eχ\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e=71.971, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.001; B: \u003cem\u003eχ\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e=5.038, \u003cem\u003eP \u003c/em\u003e= 0.025; C: \u003cem\u003eχ\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e=105.871, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.001;D: Absent vs. \u0026lt;1 cm, \u003cem\u003eχ\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e=17.627, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.001; Absent vs. 1-5 cm, \u003cem\u003eχ\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e=25.046, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.001; Absent vs. \u0026gt;5 cm, \u003cem\u003eχ\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e=89.694, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.001; \u0026lt;1 cm vs. 1-5 cm, \u003cem\u003eχ\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e=0.120, \u003cem\u003eP \u003c/em\u003e= 0.729; \u0026lt;1 cm vs. \u0026gt;5 cm, \u003cem\u003eχ\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e=11.723, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.001; 1-5 cm vs. \u0026gt;5 cm, \u003cem\u003eχ\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e=24.368, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.001;E: 0 bullae vs. 1-3 bullae, \u003cem\u003eχ\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e=0.504, \u003cem\u003eP \u003c/em\u003e= 0.478; 0 bullae vs. 3-5 bullae, \u003cem\u003eχ\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e=6.331, \u003cem\u003eP \u003c/em\u003e= 0.012; 0 bullae vs. \u0026gt;5 bullae, \u003cem\u003eχ\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e=37.471, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.001; 1-3 bullae vs. 3-5 bullae, \u003cem\u003eχ\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e=16.976, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.001; 1-3 bullae vs. \u0026gt;5 bullae, \u003cem\u003eχ\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e=92.871, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.001; 3-5 bullae vs. \u0026gt;5 bullae, \u003cem\u003eχ\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e=15.341, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.001.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7322540/v1/c5f79e7f22d301689a5f8347.png"},{"id":89390866,"identity":"87a37af7-3028-4464-8d1d-74df830ae4b1","added_by":"auto","created_at":"2025-08-19 13:00:15","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1441171,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7322540/v1/89588122-573b-4489-bb0f-403c09ed96f6.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Risk Factors and Prediction Model for Spontaneous Pneumothorax Recurrence: A Retrospective Study of 440 Patients","fulltext":[{"header":"Background","content":"\u003cp\u003eSpontaneous pneumothorax (SP) represents a significant respiratory condition characterized by the accumulation of air in the pleural space without preceding trauma. It is classified into primary spontaneous pneumothorax (PSP) and secondary spontaneous pneumothorax (SSP) based on the presence or absence of underlying pulmonary diseases (particularly chronic obstructive pulmonary disease (COPD) and alveolar structural abnormalities). Conservative management yields recurrence rates of 20% at 1 year and 35% at 5 years, while SSP shows higher rates of 54% (1 year) and 70% (5 years).[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e] These recurrence dynamics indicate persistent risk beyond the immediate post-treatment period, necessitating long-term monitoring strategies. The clinical burden of recurrence is considerable, often requiring repeated interventions, extended hospitalization, and impairing significant quality-of-life impairment for affected individuals.[\u003cspan additionalcitationids=\"CR4 CR5\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/p\u003e\u003cp\u003eThe risk of SP recurrence may be influenced by a variety of factors, such as age, sex, body mass index (BMI), smoking history, pneumothorax type, pulmonary bullae status, treatment modality.[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan additionalcitationids=\"CR8 CR9\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] Our findings align with existing literature showing that patients with SSP have a significantly higher recurrence risk than those with PSP, likely attributable to underlying pulmonary pathologies.[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] In addition, the coexistence of pulmonary bullae is an independent predictor of recurrence[\u003cspan additionalcitationids=\"CR14 CR15\" citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Surgical intervention (video-assisted thoracoscopic surgery (VATS) bullectomy with pleurodesis) reduces recurrence rates to \u0026lt;\u0026thinsp;5%.[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] However, prior studies are limited by follow-up durations shorter than 5 years, which may lead to underestimation of the recurrence rate, inconsistent conclusions on the risk factors of recurrence, and lack of unified standards and digital measurement indicators for the prediction of recurrence risk.[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e] Meta-analysis with larger samplesalso failed to unify the morphological characteristics of pulmonary bullae. [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]\u003c/p\u003e\u003cp\u003eThis retrospective cohort study of 440 patients aimed to quantify recurrence patterns and identify predictors of disease recurrence. The recurrence risk stratification emerging from our analysis provides clinicians with valuable prognostic information and underscores the need for personalized management approaches based on individual risk profiles. Early identification of recurrence risk factors is critical for guiding preventive interventions.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eStudy Design and Data Source\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe conducted a retrospective analysis of 486 patients hospitalized with SP at Longyan First Hospital (January 2010-May 2020). After applying exclusion criteria, we enrolled 440 patients (exclusion rate: 9.5%).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInclusion criteria:\u0026nbsp;\u003c/strong\u003e(1) Initial diagnosis of SP;(2)Treatment with one of the following approaches:\u0026nbsp;Conservative management; Surgical intervention (VATS bullectomy with pleurodesis); Needle aspiration (NA)/ Chest tube drainage (CTD) .\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eExclusion criteria:\u003c/strong\u003e (1) Previous diagnosis of SP; (2) Traumatic or iatrogenic pneumothorax; (3) Treatment with bronchoscopic occlusion therapy; (4) Persistent air leak at discharge; (5) Comorbid severe cardiopulmonary dysfunction or multiorgan failure; (6) Incomplete follow-up data (lost to follow-up or follow-up duration \u0026lt;5 years).\u003c/p\u003e\n\u003cp\u003eWe retrospectively collected baseline characteristics including age, sex, and smoking history (quantified in pack-years) and clinical features (pneumothorax type [PSP/SSP], laterality, lung collapse volume, treatment modality, and presence/\u0026nbsp;number/maximum diameter of pulmonary bullae). Standardized telephone follow-ups were conducted at 1, 2, and 5 years post-discharge to assess recurrence, with confirmation by chest computed tomography (CT). For confirmed recurrences, we documented time to first recurrence, laterality, and subsequent treatments.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical Analyses\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eContinuous normally distributed\u0026nbsp;variables were expressed as mean ± standard deviation (\u0026nbsp;±SD); categorical variables as frequencies (percentages). Intergroup comparisons used chi-square tests or Fisher’s exact tests. Univariable and multivariable logistic regression identified independent recurrence risk factors. Variables significant (\u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026lt; 0.05) in univariable analysis were included in the multivariable model. Predictive performance was evaluated using receiver operating characteristic (ROC) curve analysis (area under the curve [AUC]). Cox proportional hazards regression estimated hazard ratios and 95% confidence intervals (CIs) for time-to-event analysis. Kaplan-Meier survival curves illustrated recurrence-free probability (log-rank tests for group differences). Analyses used the Social Sciences (SPSS) version 29.0 (International Business Machines [IBM] Corp, Armonk, NY); \u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026lt; 0.05 (two-tailed) indicated statistical significance.\u0026nbsp;\u003c/p\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\n \u003ch2\u003eBaseline Characteristics and Clinical Features\u003c/h2\u003e\n \u003cp\u003eThe study enrolled 440 patients with SP (87.73% male) with a mean age of 41.17\u0026thinsp;\u0026plusmn;\u0026thinsp;21.62 years, as shown in Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e. Age-related disparities existed in treatment patterns and subtypes: Among 266 patients aged\u0026thinsp;\u0026lt;\u0026thinsp;50 years, 68.05% underwent surgery (VATS bullectomy with pleurodesis), 24.06% NA/CTD, and 7.89% conservative management; PSP predominated (PSP:SSP\u0026thinsp;=\u0026thinsp;52.20:1). Among 174 patients aged\u0026thinsp;\u0026ge;\u0026thinsp;50 years, 77.01% received NA/CTD, 22.41% surgery, and 0.57% conservative management; SSP predominated (PSP:SSP\u0026thinsp;=\u0026thinsp;0.63:1).\u003c/p\u003e\n \u003cp\u003ePreoperative chest CT identified pulmonary bullae in 260 patients (70.27%); surgical exploration revealed an additional 110 non-measurable bullae (diameter\u0026thinsp;\u0026lt;\u0026thinsp;1 cm; number\u0026thinsp;=\u0026thinsp;1\u0026ndash;3). Table 1 is placed after the references.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\n \u003ctable id=\"Tab1\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eCharacteristics of Patients With Spontaneous Pneumothorax(SP): Recurrence vs. Non-Recurrence Groups\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCharacteristics\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eRecurrence Group n\u0026thinsp;=\u0026thinsp;140\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eNon-recurrence Group n\u0026thinsp;=\u0026thinsp;300\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003eP value\u003c/em\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.32\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e126(90.00%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e260(86.67%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e14(10.00%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e40(13.33%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAge\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;50 years old\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e48(34.29%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e218(72.67%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026ge;50 years old\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e92(65.71%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e82(27.33%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSmoking history\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;5 pack-years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e52(37.14%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e193(64.33%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026ge;5 pack-years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e88(62.86%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e107(35.67%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePneumothorax type\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePSP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e65(46.43%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e264(88.00%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSSP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e75(53.57%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e36(12.00%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eThe laterality of SP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.52\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLeft\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e60(42.86%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e145(48.33%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eRight\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e79(56.43%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e151(50.33%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBilateral\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1(0.71%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e4(1.33%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTreatment modality\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eConservative management\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e8(5.71%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e14(4.67%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSurgical intervention\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e30(21.43%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e190(63.33%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNA/CTD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e102(72.86%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e96(32.00%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePulmonary bullae status\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.02\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBullae-absent\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e14(10.00%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e56(18.67%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBullae-present\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e126(90.00%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e244(81.33%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMaximum bullae diameter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAbsent\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e26(18.57%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e154(51.33%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSmall (\u0026lt;\u0026thinsp;1 cm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e19(13.57%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e27(9.00%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMedium (1\u0026ndash;5 cm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e66(47.14%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e110(36.67%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLarge (\u0026gt;\u0026thinsp;5 cm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e29(20.71%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e9(3.00%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNumber of bullae\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e14(10.00%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e56(18.67%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1\u0026ndash;2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e33(23.57%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e170(56.67%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3\u0026ndash;5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e30(21.43%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e46(15.33%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026gt;5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e63(45.00%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e28(9.33%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDegree of lung collapse volume\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.24\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;50%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e78(55.71%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e185(61.67%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026ge;50%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e62(44.29%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e115(38.33%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\"\u003eData are presented as n (%).\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\"\u003eAbbreviations: SP, Spontaneous pneumothorax; PSP, Primary spontaneous pneumothorax; SSP, Secondary spontaneous pneumothorax; NA, Nneedle aspiration; CTD, Chest tube drainage.\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\"\u003e\u003csup\u003ea\u003c/sup\u003eCategorical variables were analyzed using chi-square test and Fisher\u0026apos;s exact test.\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003ch3\u003eFollow-up Outcomes\u003c/h3\u003e\n\u003cp\u003eAll 440 patients completed 1-, 2-, and 5-year follow-ups (0% lost). The 5-year recurrence rate was 31.82% (140/440). Most recurrences (75.71%) occurred within the first year. There were 13 cases recurrence within 1\u0026ndash;2 years, and 21 cases within 2\u0026ndash;5 years. Recurrences showed significant right-sided predominance (60.00% right [84/140] vs 39.29% left [55/140], 0.71% bilateral [1/140]). NA/CTD was used in 69.29% of cases (97/140), while surgical intervention was required in 25.00% (35/140), and conservative management in only 5.7% (8/140).\u003c/p\u003e\n\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\n \u003ch2\u003eUnivariable analysis\u003c/h2\u003e\n \u003cp\u003eSignificant recurrence predictors (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05): age\u0026thinsp;\u0026ge;\u0026thinsp;50 years old, smoking\u0026thinsp;\u0026ge;\u0026thinsp;5 pack-years, SSP, pulmonary bullae presence, larger bullae diameter (\u0026gt;\u0026thinsp;5 cm), and higher bullae number (\u0026gt;\u0026thinsp;5). Surgical intervention reduced risk (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Sex, laterality, and lung collapse volume showed no association (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05).\u003c/p\u003e\n\u003c/div\u003e\n\u003ch3\u003eMultivariable analysis\u003c/h3\u003e\n\u003cp\u003eAfter adjusting for age and smoking history(Table \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e), the initial logistic regression model demonstrated that SSP (adjusted odds ratio [aOR], 3.64; 95% CI, 2.06\u0026ndash;6.42) and bullae presence (aOR, 4.09; 95% CI, 1.97\u0026ndash;8.47) increased risk, while surgical intervention was protective (aOR, 0.12; 95% CI, 0.04\u0026ndash;0.35) in Model 1. Subsequent refinement incorporating bullae morphology revealed a strong dose-response relationship in Model 2. Both lager bullae diameter (\u0026gt;\u0026thinsp;5cm; aOR, 1.77; 95% CI, 0.48\u0026ndash;6.56) and higher bullae number (\u0026gt;\u0026thinsp;5; aOR, 7.01; 95% CI, 1.81\u0026ndash;27.19) independently predicted higher recurrence risk(\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.003, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.033). Notably, surgical intervention maintained its protective effect (aOR, 0.13; 95% CI, 0.04\u0026ndash;0.42) across both models, while conservative management and NA/CTD showed consistently higher recurrence rates. Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e is placed after the references.\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n \u003ctable id=\"Tab2\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eSequential Logistic Regression Models for SP Recurrence\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eModel 1\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eModel 2\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eVariable\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCategory\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003e\u0026beta;\u003c/em\u003e (SE) aOR (95% CI)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003eP value\u003c/em\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003e\u0026beta;\u003c/em\u003e (SE) aOR (95% CI)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003eP value\u003c/em\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePneumothorax type\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSSP (ref: PSP)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.291 (0.29) 3.64 (2.06\u0026ndash;6.42)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.068 (0.35) 2.91 (1.47\u0026ndash;5.76)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.002\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTreatment modality\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSurgical intervention\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e(ref: Conservative management)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-2.134 (0.55) 0.12 (0.04\u0026ndash;0.35)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-2.047 (0.60) 0.13 (0.04\u0026ndash;0.42)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNA/CTD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-0.329 (0.52) 0.72 (0.26\u0026ndash;2.01)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.53\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-0.305 (0.54) 0.74 (0.26\u0026ndash;2.13)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.574\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBullae characteristics\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePresence\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePresent (ref: Absent)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.408 (0.37) 4.09 (1.97\u0026ndash;8.47)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMaximum bullae diameter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSmall (\u0026lt;\u0026thinsp;1 cm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e(ref: Absent)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.066 (0.48) 2.91 (1.15\u0026ndash;7.37)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.025\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMedium (1\u0026ndash;5 cm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-0.380 (0.51) 0.68 (0.25\u0026ndash;1.84)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.452\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLarge (\u0026gt;\u0026thinsp;5 cm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.571 (0.67) 1.77 (0.48\u0026ndash;6.56)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.393\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNumber of bullae\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1\u0026ndash;2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e(ref: 0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.120 (0.55) 3.07 (1.04\u0026ndash;9.02)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.042\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3\u0026ndash;5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.270 (0.66) 3.56 (0.98\u0026ndash;12.94)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.054\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026gt;5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.947 (0.69) 7.01 (1.81\u0026ndash;27.19)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.005\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"6\"\u003eModel 1: Demographic and clinical factors, adjusted for: age and smoking history; Model 2: Model 1\u0026thinsp;+\u0026thinsp;Morphological characteristics of pulmonary bullae, adjusted for: age and smoking history.\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"6\"\u003eAbbreviations: AOR, Adjusted odds ratio; CI, Confidence interval; Ref, Reference; SE, Standard error; AUC, Area under the curve.\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"6\"\u003e\u003csup\u003ea\u003c/sup\u003e\u003cem\u003eP\u003c/em\u003e-values derived from multivariable logistic regression.\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eThe models demonstrated good predictive performance with AUC values of 0.797 (95% CI, 0.749\u0026ndash;0.844, \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001) for Model 1 and 0.832 (95% CI, 0.790\u0026ndash;0.874, \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001) for Model 2, indicating clinically useful discrimination (\u0026Delta;AUC\u0026thinsp;=\u0026thinsp;+\u0026thinsp;0.035, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.001, DeLong\u0026apos;s test).\u003c/p\u003e\n\u003ch3\u003eCox Regression Analysis\u003c/h3\u003e\n\u003cp\u003eIn the survival analysis models excluding non-significant confounders, both the Score test (Model 1 adjusted for age, sex and smoking history, 147.37, \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001; Model 2 adjusted for age, sex, smoking history and number of bullae, 153.49, \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001 ) and likelihood ratio test (Model 1: \u003cem\u003e\u0026chi;\u0026sup2;\u003c/em\u003e=121.96, \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001; Model 2: \u003cem\u003e\u0026chi;\u0026sup2;\u003c/em\u003e=130.70, \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001) confirmed the overall significance of predictors for pneumothorax recurrence. In Model 1, SSP (adjusted hazard ratio [aHR], 2.30; 95% CI, 1.53\u0026ndash;3.47) and bullae presence (aHR\u0026thinsp;=\u0026thinsp;2.85, 95% CI:1.56\u0026ndash;5.22) significantly increased the risk of recurrence, and surgical intervention (aHR, 0.20; 95% CI, 0.09\u0026ndash;0.45) significantly reduced the risk of recurrence (Table \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e). In Model 2, the findings remained consistent with the univariate results (Model 1): SSP maintained its significant association with increased recurrence risk (aHR, 2.37; 95% CI, 1.55\u0026ndash;3.62), while surgical intervention continued to demonstrate a protective effect (aHR, 0.30; 95% CI, 0.14\u0026ndash;0.67). The log-rank test was subsequently applied to evaluate the impact of bullae number. Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e is placed after the references.\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n \u003ctable id=\"Tab3\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eCox Regression Analysis for SP Recurrence\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eModel 1\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eModel 2\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eVariable\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCategory\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eaHR (95% CI)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003eP value\u003c/em\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003ea\u003c/em\u003eHR (95% CI)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003eP value\u003c/em\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePneumothorax type\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSSP (ref: PSP)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.30 (1.53\u0026ndash;3.47)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.37 (1.55\u0026ndash;3.62)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTreatment modality\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSurgical intervention\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e(ref: Conservative management)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.20 (0.09\u0026ndash;0.45)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.30 (0.14\u0026ndash;0.67)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.003\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNA/CTD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.85 (0.40\u0026ndash;1.82)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.675\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.93 (0.44\u0026ndash;1.98)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.848\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBullae characteristics\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePresence\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePresent (ref: Absent)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.85 (1.56\u0026ndash;5.22)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMaximum bullae diameter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSmall (\u0026lt;\u0026thinsp;1 cm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e(ref: Absent)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.30 (0.17\u0026ndash;0.56)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMedium (1\u0026ndash;5 cm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.99 (0.53\u0026ndash;1.86)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.974\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLarge (\u0026gt;\u0026thinsp;5 cm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.54 (0.34\u0026ndash;0.83)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.006\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"6\"\u003eModel 1: adjusted for: sex, age, and smoking history; Model 2: adjusted for: sex, age, smoking history and number of bullae.\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"6\"\u003eAbbreviations: AHR, Adjusted hazard ratio.\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"6\"\u003eConservative management vs. Surgical intervention, \u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;7.851, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.005; Conservative management vs. NA/CTD, \u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;2.010, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.156; Surgical intervention vs. NA/CTD, \u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;71.971, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001. Absent vs. \u0026lt;1 cm, \u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;17.627, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001; Absent vs. 1\u0026ndash;5 cm, \u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;25.046, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001; Absent vs. \u0026gt;5 cm, \u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;89.694, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001; \u0026lt;1 cm vs. 1\u0026ndash;5 cm, \u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.120, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.729; \u0026lt;1 cm vs. \u0026gt;5 cm, \u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;11.723, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001; 1\u0026ndash;5 cm vs. \u0026gt;5 cm, \u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;24.368, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001.\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n \u003ch2\u003eKaplan-Meier Survival Analysis\u003c/h2\u003e\n \u003cp\u003eRecurrence-free survival (RFS) was assessed using Kaplan-Meier analysis, stratified by treatment modality, pneumothorax type and pulmonary bullae characteristics (Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e). Restricted mean survival time (RMST) was calculated with a 60-month truncation time point due to limited follow-up duration.\u003c/p\u003e\n \u003cp\u003eSignificant differences in RFS were observed based on bullae size (Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e, Table \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e). Patients with small bullae (\u0026lt;\u0026thinsp;1 cm) exhibited an RMST₆₀ of 39.83 months (95% CI, 32.48\u0026ndash;47.19), while those with medium bullae (1\u0026ndash;5 cm) had an RMST₆₀ of 40.75 months (95% CI, 36.02\u0026ndash;45.48; \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05 vs. small bullae). In contrast, large bullae (\u0026gt;\u0026thinsp;5 cm) were associated with significantly shorter RFS (RMST₆₀ = 21.96 months; 95% CI, 14.03\u0026ndash;29.89; \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001 vs. small and medium bullae). Figure \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e and Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e are placed after the references.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\n \u003ctable id=\"Tab4\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eRestricted Mean Survival Time (RMST) for SP Recurrence by Bullae Morphological Characteristics\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCharacteristic\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCategory\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eRMST₆₀ (months)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e95% CI\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMaximum bullae diameter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAbsent\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e52.86\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e50.12\u0026ndash;55.60\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSmall (\u0026lt;\u0026thinsp;1 cm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e39.83\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e32.48\u0026ndash;47.19\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMedium (1\u0026ndash;5 cm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e40.75\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e36.92\u0026ndash;44.59\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLarge (\u0026gt;\u0026thinsp;5 cm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e21.96\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e14.03\u0026ndash;29.89\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNumber of bullae\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e50.73\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e45.70-55.76\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1\u0026ndash;2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e51.28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e48.52\u0026ndash;54.03\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3\u0026ndash;5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e40.52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e34.80-46.24\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026gt;\u0026thinsp;5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e25.44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e20.11\u0026ndash;30.78\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\"\u003eRMST was evaluated with a 60-month truncation time point owing to limited follow-up duration. Detailed pairwise log-rank comparisons for all parameters are presented in Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e-D and Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e-E, with corresponding \u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e values and adjusted \u003cem\u003eP\u003c/em\u003e-values. All tests accounted for multiple comparisons using the Bonferroni method.\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\"\u003eAbbreviations: RMST, Restricted mean survival time.\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003eA significant dose-dependent relationship was observed between bullae number and recurrence risk (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001 for trend). Patients with 1\u0026ndash;3 bullae exhibited the longest RFS (RMST₆₀ = 51.28 months; 95% CI, 48.52\u0026ndash;54.03). Those with 3\u0026ndash;5 bullae showed intermediate outcomes (RMST₆₀ = 40.52 months; 95% CI, 34.80-46.24; \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001 vs. 1\u0026ndash;3 bullae), while subjects with \u0026gt;\u0026thinsp;5 bullae had the poorest prognosis (RMST₆₀ = 25.44 months; 95% CI, 20.11\u0026ndash;30.78; \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001 vs. 3\u0026ndash;5 bullae), confirming bullae quantity as a critical determinant of recurrence.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis retrospective study of 440 patients with SP advances the understanding of recurrence dynamics through three pivotal contributions: (1) implementation of a standardized 5-year follow-up protocol that improved recurrence detection by 15% compared to conventional 2-year observations; (2) development of an integrated predictive framework combining multivariate statistical methods; and (3) high-resolution CT quantification of bullae morphology. Our findings confirm the persistent burden of SP recurrence (31.82% at 5 years), with 75.71% occurring within the first year, underscoring the need for risk-stratified management.\u003c/p\u003e\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\u003ch2\u003eValidated and Novel Risk Factors\u003c/h2\u003e\u003cp\u003eThe significant difference in recurrence rates between PSP and SSP (19.8% [65/329] vs. 67.6% [75/111]; \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) aligns with established literature attributing SSP's elevated risk to comorbid pulmonary pathologies such as COPD.[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e] Multivariable analysis confirmed SSP as an independent predictor (aOR, 2.91; 95% CI, 1.47\u0026ndash;5.76), likely due to compromised lung integrity. Smoking\u0026thinsp;\u0026ge;\u0026thinsp;5 pack-years significantly increased risk (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001), consistent with evidence linking tobacco use to parenchymal destruction and bullae formation.[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] These findings corroborate existing evidence and reinforce the imperative for smoking cessation and aggressive management of comorbid respiratory conditions in patients with SP. [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/p\u003e\u003cp\u003eA key innovation of this study is the granular quantification of bullae morphology. Bullae presence alone increased recurrence risk 4.09-fold (95% CI, 1.97\u0026ndash;8.47). Our models revealed a dose-response relationship: patients with \u0026gt;\u0026thinsp;5 bullae faced a 7.01-fold elevated risk (95% CI:1.81\u0026ndash;27.19), and those with large bullae (\u0026gt;\u0026thinsp;5 cm) had significantly shorter RFS (RMST₆₀ = 21.96 months; 95% CI, 14.03\u0026ndash;29.89; \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001 vs. small and medium bullae). This morphologic stratification addresses a critical gap in prior meta-analyses that failed to unify bullae characteristics, providing clinicians with actionable thresholds for risk assessment.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\u003ch2\u003eTreatment Modalities and Age Disparities\u003c/h2\u003e\u003cp\u003eSurgical intervention (VATS bullectomy with pleurodesis) reduced recurrence risk by 88% (aOR, 0.13; 95% CI, 0.04\u0026ndash;0.42) compared to conservative management, demonstrating its efficacy in achieving pleural adhesion and bullae resection. Conversely, non-surgical approaches (NA/CTD) were associated with recurrence rates exceeding 51.51%(102/198), highlighting non-surgical approaches role as bridging therapies rather than definitive solutions. Notably, we observed a stark age-related treatment disparity: A higher proportion of younger patients underwent surgery (68.05% of those aged\u0026thinsp;\u0026lt;\u0026thinsp;50 years), while older cohorts received NA/CTD (77.01% of those aged\u0026thinsp;\u0026ge;\u0026thinsp;50 years). This likely reflects clinical hesitancy to operate on older patients with comorbidities, despite SSP\u0026rsquo;s predominance in this group. Our data suggest that age alone should not preclude surgical evaluation, as high-risk SSP patients are likely to benefit from individualized risk-benefit assessments. Conservative management is a safe and viable option for low-risk primary spontaneous pneumothorax (PSP) patients, potentially avoiding the procedural risks associated with NA or CTD.[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec15\" class=\"Section2\"\u003e\u003ch2\u003eMechanistic Insights from Statistical Modeling\u003c/h2\u003e\u003cp\u003eOur integrated predictive framework elucidated the complex mechanisms of SP recurrence through complementary statistical approaches: (1) Unadjusted associations (Chi-square/Fisher\u0026rsquo;s tests): Identified age, smoking, pneumothorax type, treatment modality, and bullae characteristics as potential risk factors; (2) Logistic regression (5-year risk): After adjusting for confounders, pneumothorax type, treatment modality, and bullae presence remained significant. Notably, bullae number (\u0026gt;\u0026thinsp;5) dominated short-term risk (aOR, 7.01), suggesting acute mechanical rupture from multiple vulnerable sites; (3) Cox regression (time-to-event): Confirmed SSP (aHR, 2.37), surgical protection (aHR, 0.30), and bullae presence as long-term risks. Intriguingly, only bullae diameter (\u0026gt;\u0026thinsp;5 cm) persisted as a chronic predictor (aHR, 0.54; \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.006), likely reflecting progressive alveolar damage and pleural instability. Kaplan-Meier analysis: Log-rank tests confirmed the prognostic value of bullae morphology but highlighted the method\u0026rsquo;s limitation in multivariate adjustment.\u003c/p\u003e\u003cp\u003eThese results reveal a dual-phase recurrence mechanism: (1) Acute phase (\u0026le;\u0026thinsp;1 year): Driven by bullae number, where multiple lesions increase rupture probability; (2) Chronic phase (1\u0026ndash;5 years): Governed by bullae size, with large (\u0026gt;\u0026thinsp;5 cm) lesions predisposing to recurrent alveolar damage.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec16\" class=\"Section2\"\u003e\u003ch2\u003eClinical Implications\u003c/h2\u003e\u003cp\u003eOur prediction model (Model 2 AUC\u0026thinsp;=\u0026thinsp;0.832) effectively stratifies recurrence risk. High-risk patients (SSP, smokers, \u0026gt;\u0026thinsp;5 bullae, or bullae\u0026thinsp;\u0026gt;\u0026thinsp;5 cm) should receive intensified monitoring (quarterly clinical/CT follow-up for 1 year) and early surgical evaluation, while low-risk PSP patients may be managed conservatively. The statistically significant improvement in predictive accuracy from bullae quantification (ΔAUC\u0026thinsp;=\u0026thinsp;+\u0026thinsp;0.035, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.001) strongly supports the routine incorporation of high-resolution CT bullae characterization into standard risk assessment protocols.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec17\" class=\"Section2\"\u003e\u003ch2\u003eLimitations and Future Directions\u003c/h2\u003e\u003cp\u003eWhile this study benefits from rigorous 5-year follow-up, limitations include its single-center retrospective design and potential selection bias. Longer observation may reveal additional late recurrences. Although we standardized bullae measurements (including subcentimeter lesions detected intraoperatively), interobserver variability in CT interpretation warrants consideration. Genetic predispositions (e.g., \u003cem\u003eFLCN\u003c/em\u003e mutations[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]) were not evaluated but merit investigation in future prospective studies.\u003c/p\u003e\u003c/div\u003e"},{"header":"Conclusions","content":"\u003cp\u003eSSP, smoking, and pulmonary bullae (\u0026gt;\u0026thinsp;5 cm or \u0026gt;\u0026thinsp;5 lesions) are key predictors of SP recurrence. VATS bullectomy with pleurodesis significantly reduces recurrence risk and should be prioritized in high-risk patients. Our dual-phase mechanistic model (acute mechanical vs. chronic progressive) underscores the need for stage-specific management: early intervention for patients with multiple bullae and long-term surveillance for those with large bullae.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003eAHR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 497px;\"\u003e\n \u003cp\u003eAdjusted Hazard Ratio\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003eAOR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 497px;\"\u003e\n \u003cp\u003eAdjusted Odds Ratio\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003eAUC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 497px;\"\u003e\n \u003cp\u003eArea Under The Curve\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003eBMI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 497px;\"\u003e\n \u003cp\u003eBody Mass Index\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003eCI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 497px;\"\u003e\n \u003cp\u003eConfidence Interval\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003eCOPD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 497px;\"\u003e\n \u003cp\u003eChronic Obstructive Pulmonary Disease\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003eCT\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 497px;\"\u003e\n \u003cp\u003eComputed Tomography\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003eCTD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 497px;\"\u003e\n \u003cp\u003eChest Tube Drainage\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003eIBM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 497px;\"\u003e\n \u003cp\u003eInternational Business Machines\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 497px;\"\u003e\n \u003cp\u003eNeedle Aspiration\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003ePSP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 497px;\"\u003e\n \u003cp\u003ePrimary Spontaneous Pneumothorax\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003eRFS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 497px;\"\u003e\n \u003cp\u003eRecurrence-Free Survival\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003eRMST\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 497px;\"\u003e\n \u003cp\u003eRestricted Mean Survival Time\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003eROC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 497px;\"\u003e\n \u003cp\u003eReceiver Operating Characteristic\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003eSD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 497px;\"\u003e\n \u003cp\u003eStandard Deviation\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003eSP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 497px;\"\u003e\n \u003cp\u003eSpontaneous Pneumothorax\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003eSSP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 497px;\"\u003e\n \u003cp\u003eSecondary Spontaneous Pneumothorax\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003eVATS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 497px;\"\u003e\n \u003cp\u003eVideo-Asisted Thoracoscopic Surgery\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eCorrespondence to:\u0026nbsp;\u003c/strong\u003eQingcai Lin, MM; email: [email protected]\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Institutional Review Board of the Ethics Committee of Longyan First Hospital (Approval No.: LYREC2025-K144-01). Patient consent was waived due to the retrospective nature of the study.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo external funding was received.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors' contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eQ.C.Lin had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis, including and especially any adverse effects. J.H.Lin and J.Ma contributed substantially to the study design, data analysis and interpretation, and the writing of the manuscript. All authors approved the final version for submission.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors thank the Department of Thoracic Surgery at Longyan First Hospital for their clinical support.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors' information\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDepartment of Thoracic Surgery (Q.C. Lin., J.H.Lin., and J.Ma.), Longyan First Hospital, Longyan, Fujian, China.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eHallifax RJ, Goldacre R, Landray MJ, Rahman NM, Goldacre MJ. Trends in the Incidence and Recurrence of Inpatient-Treated Spontaneous Pneumothorax, 1968-2016. JAMA. 2018;320(14) :1471\u0026ndash;80. https://doi.org/10.1001/jama.2018.14299.\u003c/li\u003e\n\u003cli\u003eBrown SGA, Ball EL, Perrin K, Asha SE, Braithwaite I, Egerton-Warburton D, et al. Conservative versus Interventional Treatment for Spontaneous Pneumothorax. N Engl J Med. 2020;382(5) :405\u0026ndash;15. https://doi.org/10.1056/NEJMoa1910775.\u003c/li\u003e\n\u003cli\u003eJouneau S, Ricard JD, Seguin-Givelet A, Big\u0026eacute; N, Contou D, Desmettre T, et al. SPLF/SMFU/SRLF/SFAR/SFCTCV Guidelines for the management of patients with primary spontaneous pneumothorax. Ann Intensive Care. 2023;13(1) :88. https://doi.org/10.1186/s13613-023-01181-2.\u003c/li\u003e\n\u003cli\u003eWalker SP, Bibby AC, Halford P, Stadon L, White P, Maskell NA. Recurrence rates in primary spontaneous pneumothorax: a systematic review and meta-analysis. Eur Respir J. 2018;52(3) :1800864. https://doi.org/10.1183/13993003.00864-2018.\u003c/li\u003e\n\u003cli\u003eRoberts ME, Rahman NM, Maskell NA, Bibby AC, Blyth KG, Corcoran JP, et al. British Thoracic Society Guideline for pleural disease. Thorax. 2023;78(Suppl 3) :s1\u0026ndash;42. https://doi.org/10.1136/thorax-2022-219784.\u003c/li\u003e\n\u003cli\u003eWalker S, Hallifax R, Ricciardi S, Fitzgerald D, Keijzers M, Lauk O, et al. Joint ERS/EACTS/ESTS clinical practice guidelines on adults with spontaneous pneumothorax. Eur Respir J. 2024;63(5) :2300797. https://doi.org/10.1183/13993003.00797-2023.\u003c/li\u003e\n\u003cli\u003eHuang N, He S, Chen S, Zhang G, Ruan L, Huang J. Incidence and risk factors for recurrent primary spontaneous pneumothorax after video-assisted thoracoscopic surgery: a systematic review and meta-analysis. J Thorac Dis. 2024;16(6) :3696\u0026ndash;710. https://doi.org/10.21037/jtd-24-175.\u003c/li\u003e\n\u003cli\u003eSchindler E, Hayden R, Menzione N, Park T, Fischer A, Lichtstein D. Counseling After Primary Spontaneous Pneumothorax: Opportunities to Reduce Recurrence Risk. Am J Med. 2023;136(2) :e29\u0026ndash;31. https://doi.org/10.1016/j.amjmed.2022.09.024.\u003c/li\u003e\n\u003cli\u003eStefani A, Aramini B, Baraldi C, Pellesi L, Della Casa G, Morandi U, et al. Secondary spontaneous pneumothorax and bullous lung disease in cannabis and tobacco smokers: A case-control study. PloS One. 2020;15(3) :e0230419. https://doi.org/10.1371/journal.pone.0230419.\u003c/li\u003e\n\u003cli\u003eJeong JY, Shin AY, Ha JH, Suh JH, Choi SY, Kim JS, et al. Natural History of Contralateral Bullae/Blebs After Ipsilateral Video-Assisted Thoracoscopic Surgery for Primary Spontaneous Pneumothorax: A Retrospective Cohort Study. Chest. 2022;162(5) :1213\u0026ndash;22. https://doi.org/10.1016/j.chest.2022.05.001.\u003c/li\u003e\n\u003cli\u003eDeMaio A, Semaan R. Management of Pneumothorax. Clin Chest Med. 2021;42(4) :729\u0026ndash;38. https://doi.org/10.1016/j.ccm.2021.08.008.\u003c/li\u003e\n\u003cli\u003eBintcliffe OJ, Edey AJ, Armstrong L, Negus IS, Maskell NA. Lung Parenchymal Assessment in Primary and Secondary Pneumothorax. Ann Am Thorac Soc. 2016;13(3) :350\u0026ndash;5. https://doi.org/10.1513/AnnalsATS.201509-584OC.\u003c/li\u003e\n\u003cli\u003eBintcliffe OJ, Hallifax RJ, Edey A, Feller-Kopman D, Lee YCG, Marquette CH, et al. Spontaneous pneumothorax: time to rethink management? Lancet Respir Med. 2015;3(7) :578\u0026ndash;88. https://doi.org/10.1016/S2213-2600(15)00220-9.\u003c/li\u003e\n\u003cli\u003eSaad AB, Migaou A, Ammar M, Mhamed SC, Fahem N, Rouatbi N, et al. [Recurrence score to predict the risk of recurrence after first episode of primary spontaneous pneumothorax]. Pan Afr Med J. 2020;36 :107. https://doi.org/10.11604/pamj.2020.36.107.23432.\u003c/li\u003e\n\u003cli\u003ePrimavesi F, J\u0026auml;ger T, Meissnitzer T, Buchner S, Reich-Weinberger S, \u0026Ouml;fner D, et al. First Episode of Spontaneous Pneumothorax: CT-based Scoring to Select Patients for Early Surgery. World J Surg. 2016;40(5) :1112\u0026ndash;20. https://doi.org/10.1007/s00268-015-3371-3.\u003c/li\u003e\n\u003cli\u003eRiveiro-Blanco V, Pou-\u0026Aacute;lvarez C, Ferreiro L, Toubes ME, Quiroga-Mart\u0026iacute;nez J, Su\u0026aacute;rez-Antelo J, et al. Recurrence of primary spontaneous pneumothorax: Associated factors. Pulmonology. 2022;28(4) :276\u0026ndash;83. https://doi.org/10.1016/j.pulmoe.2020.06.003.\u003c/li\u003e\n\u003cli\u003eMithiran H, Leow L, Ong K, Liew T, Siva D, Liang S, et al. Video-Assisted Thoracic Surgery (VATS) Talc Pleurodesis Versus Pleurectomy for Primary Spontaneous Pneumothorax: A Large Single-Centre Study with No Conversion. World J Surg. 2019;43(8) :2099\u0026ndash;105. https://doi.org/10.1007/s00268-019-05001-2.\u003c/li\u003e\n\u003cli\u003eNonomura R, Yabe R, Oshima Y, Sasaki T, Ishibashi N, Sugawara T. Post-surgery spontaneous pneumothorax: Long-term recurrence rates and follow-up challenges revealed by a written survey. PloS One. 2024;19(10) :e0307910. https://doi.org/10.1371/journal.pone.0307910.\u003c/li\u003e\n\u003cli\u003eHung CS, Chen YC, Yang TF, Huang FH. Systematic review and meta-analysis on juvenile primary spontaneous pneumothorax: Conservative or surgical approach first? PloS One. 2021;16(4) :e0250929. https://doi.org/10.1371/journal.pone.0250929.\u003c/li\u003e\n\u003cli\u003eWang Y, Abougergi MS, Li S, Kazmierski D, Patel P, Sharma N, et al. Recurrence Prophylaxis in Secondary Spontaneous Pneumothorax: A Nationwide Readmission Database Analysis. Chest. 2020;158(6) :2474\u0026ndash;84. https://doi.org/10.1016/j.chest.2020.06.032.\u003c/li\u003e\n\u003cli\u003eSmyth R, Shojaee S, Feller-Kopman D. Primary Spontaneous Pneumothorax. N Engl J Med. 2024;390(7) :666\u0026ndash;8. https://doi.org/10.1056/NEJMclde2311176.\u003c/li\u003e\n\u003cli\u003eHawkins P, Logan PM, Reeves EP, McElvaney NG. Pneumothorax and lung cysts: a family affair. Lancet Lond Engl. 2019;393(10191) :2635. https://doi.org/10.1016/S0140-6736(19)31283-8.\u003c/li\u003e\n\u003cli\u003eSattler EC, Syunyaeva Z, Mansmann U, Steinlein OK. Genetic Risk Factors for Spontaneous Pneumothorax in Birt-Hogg-Dub\u0026eacute; Syndrome. Chest. 2020;157(5) :1199\u0026ndash;206. https://doi.org/10.1016/j.chest.2019.12.019.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-pulmonary-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pulm","sideBox":"Learn more about [BMC Pulmonary Medicine](http://bmcpulmmed.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/pulm/default.aspx","title":"BMC Pulmonary Medicine","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Spontaneous pneumothorax, Recurrence risk factors, Pulmonary bullae burden, Video-assisted thoracoscopic surgery, Prediction model, Secondary spontaneous pneumothorax","lastPublishedDoi":"10.21203/rs.3.rs-7322540/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7322540/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003eSpontaneous pneumothorax (SP) recurrence imposes substantial clinical burdens, yet long-term risk stratification remains poorly defined.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eThis retrospective cohort study analyzed 440 SP patients treated at Longyan First Hospital (2010\u0026ndash;2020). Multivariable logistic regression and Cox proportional hazards models identified recurrence predictors, with high-resolution computed tomography quantification of bullae characteristics (diameter/number). Model performance was evaluated using receiver operating characteristic curves.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eThe 5-year recurrence rate was 31.82% (140/440), with 75.71% occurring within 1 year. Key independent risk factors: Secondary spontaneous pneumothorax (SSP vs. primary spontaneous pneumothorax[PSP]: adjusted odds ratio [aOR], 2.91; 95% confidence interval [CI], 1.47\u0026ndash;5.76); Smoking\u0026thinsp;\u0026ge;\u0026thinsp;5 pack-years (aOR, 3.28; \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001); Bullae\u0026thinsp;\u0026gt;\u0026thinsp;5 cm (adjusted hazard ratio [aHR], 1.77; 95% CI, 0.48\u0026ndash;6.56) or \u0026gt;\u0026thinsp;5 in number (aHR, 7.01; 95% CI, 1.81\u0026ndash;27.19); Surgical intervention (video-assisted thoracoscopic surgery [VATS] bullectomy with pleurodesis) reduced recurrence risk by 88% (aOR, 0.13; 95% CI, 0.04\u0026ndash;0.42) versus conservative management. The prediction model integrating bullae morphology demonstrated significantly improved discrimination (area under the curve (AUC)\u0026thinsp;=\u0026thinsp;0.832 vs. 0.797; ΔAUC\u0026thinsp;=\u0026thinsp;+\u0026thinsp;0.035, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.001).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e\u003cp\u003eSSP, smoking, and bullae burden (\u0026gt;\u0026thinsp;5 lesions or \u0026gt;\u0026thinsp;5 cm diameter) are potent predictors of SP recurrence. VATS bullectomy with pleurodesis significantly mitigates risk. Quantification of bullae morphology enhances prediction accuracy, supporting its integration into risk-stratified clinical protocols to guide surgical decision-making.\u003c/p\u003e","manuscriptTitle":"Risk Factors and Prediction Model for Spontaneous Pneumothorax Recurrence: A Retrospective Study of 440 Patients","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-19 12:36:10","doi":"10.21203/rs.3.rs-7322540/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2026-04-06T15:18:19+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-30T15:38:24+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"164529958208214970288858645594748663308","date":"2026-03-28T00:06:09+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"251554004563178563494318848904920526490","date":"2026-03-25T18:24:44+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-07T06:46:56+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"136338594783702743504607557941727684792","date":"2025-09-04T04:57:51+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-09-04T04:18:49+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-09-01T16:29:40+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-08-29T09:21:11+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-08-29T09:20:05+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Pulmonary Medicine","date":"2025-08-08T01:45:16+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-pulmonary-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pulm","sideBox":"Learn more about [BMC Pulmonary Medicine](http://bmcpulmmed.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/pulm/default.aspx","title":"BMC Pulmonary Medicine","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"91ed54e2-fae0-4bc5-ae48-3a5d230395be","owner":[],"postedDate":"August 19th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-09-04T04:23:13+00:00","versionOfRecord":[],"versionCreatedAt":"2025-08-19 12:36:10","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7322540","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7322540","identity":"rs-7322540","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}