Outsourced CT Reporting versus Clinical Assessment for Diagnosing Acute Appendicitis: A Retrospective Diagnostic Accuracy Study

Outsourced CT Reporting versus Clinical Assessment for Diagnosing Acute Appendicitis: A Retrospective Diagnostic Accuracy Study | 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 Outsourced CT Reporting versus Clinical Assessment for Diagnosing Acute Appendicitis: A Retrospective Diagnostic Accuracy Study Sezer Gökçen This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8476177/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Outsourced radiology interpretation is increasingly used to maintain emergency imaging workflows, yet its diagnostic performance in suspected acute appendicitis remains uncertain. We compared outsourced non-contrast CT reporting with bedside clinical assessment in a surgically managed cohort. Methods This retrospective diagnostic accuracy study included adults (≥ 18 years) who underwent appendectomy for suspected acute appendicitis. Index tests were outsourced CT reports and the attending surgeon’s preoperative clinical assessment. The reference standard was intraoperative and/or histopathological diagnosis. Sensitivity, specificity and accuracy were calculated with 95% confidence intervals. Results Among 573 patients, appendicitis was confirmed in 492 (85.9%) and negative appendectomy occurred in 81 (14.1%). Outsourced CT reporting yielded sensitivity 87.4% (95% CI 84.1–90.1), specificity 75.3% (95% CI 64.8–83.6) and accuracy 91.4%. Clinical assessment yielded sensitivity 97.6% (95% CI 95.8–98.6), specificity 54.3% (95% CI 43.6–64.5) and accuracy 85.7%. Conclusions In this cohort, outsourced non-contrast CT reports showed higher specificity than clinical assessment, but clinically meaningful false-positive reporting may contribute to potentially avoidable appendectomies. Quality assurance and standardized protocols may improve performance in outsourced services. Trial registration: Not applicable. acute appendicitis computed tomography teleradiology outsourced radiology Modified Alvarado Score diagnostic accuracy Figures Figure 1 Background Acute appendicitis is among the most frequent causes of acute abdominal pain requiring urgent surgical evaluation and remains a major driver of emergency department admissions and appendectomy worldwide.[ 1 , 2 ] Despite being a common diagnosis, its clinical presentation can be nonspecific, overlapping with gynecologic, urinary, and gastrointestinal conditions, particularly in women and older adults.[ 3 ] Historically, clinicians tolerated relatively high negative appendectomy rates to avoid missed or perforated appendicitis; however, the availability of clinical scoring systems and cross-sectional imaging has shifted modern practice toward greater diagnostic precision.[ 4 , 5 ] Clinical scores such as the Alvarado and modified Alvarado scores (MAS) aggregate symptoms, signs, and basic laboratory parameters into a simple bedside probability estimate and can help standardize decision-making.[ 6 , 7 ] Computed tomography (CT) is widely used when the diagnosis is uncertain or when complications and alternative diagnoses must be considered.[ 1 , 8 ] Systematic reviews report high diagnostic performance of CT for appendicitis in adults, although accuracy depends on patient selection, protocol (contrast vs non-contrast), and reader experience.[ 8 , 9 ] In many institutions, radiology services—especially out-of-hours coverage—are partially or fully provided via teleradiology/outsourcing models. While teleradiology can improve timeliness and access, discordant interpretations and variability in reporting quality remain important safety and governance concerns.[ 10 – 12 ] In this context, understanding how outsourced CT reports perform in real-world surgical pathways is important. The primary aim of this study was to assess and compare the diagnostic accuracy of outsourced non-contrast CT reports and clinical assessment using MAS for detecting acute appendicitis, using operative and histopathological findings as the reference standard. Methods Study design and reporting This retrospective diagnostic accuracy study was conducted at Ağrı Training and Research Hospital (Ağrı, Türkiye) and is reported in line with STARD 2015 where applicable.[ 13 ] Participants Consecutive adult patients (≥ 18 years) who underwent appendectomy for suspected acute appendicitis between January 2020 and January 2025 were screened. The analyzed cohort consisted of patients with complete clinical assessment, a preoperative non-contrast abdominal CT performed during the index emergency visit, and an available operative and/or histopathological final diagnosis. Inclusion criteria (i) clinical suspicion of acute appendicitis; (ii) preoperative non-contrast CT performed at our institution; (iii) an outsourced radiology report available for the CT study; (iv) appendectomy performed during the index admission; and (v) intraoperative findings and/or histopathology available. Exclusion criteria pregnancy, missing key clinical or imaging data, inadequate/poor-quality CT imaging, and prior appendectomy. Clinical assessment (index test 1): Clinical probability was assessed using the Modified Alvarado Score (MAS), incorporating migration of pain, right lower quadrant tenderness, anorexia, nausea/vomiting, fever, and leukocytosis.[ 7 ] Consistent with common clinical practice, MAS in the high-probability range (≥ 7) was categorized as ‘clinically positive’; lower scores were categorized as ‘clinically negative’. CT acquisition and outsourced reporting (index test 2): Non-contrast abdominal CT scans were acquired using an Alexion CT scanner (Canon Medical Systems, Otawara, Japan). Scans were obtained in the supine position without intravenous or oral contrast, and images were typically reconstructed at 3–5 mm slice thickness with multiplanar reformations (coronal and sagittal) according to the institutional emergency abdomen protocol. CT images were interpreted by external radiology providers as part of an outsourced reporting workflow. For this analysis, CT was categorized as positive when the final report impression favored acute appendicitis and negative otherwise. CT images were not re-interpreted by local radiologists for study purposes. Reference standard The final diagnosis of acute appendicitis was defined by intraoperative macroscopic findings consistent with acute appendicitis and/or histopathological confirmation of appendicitis. Negative appendectomy was defined as absence of appendicitis on histopathology. Outcomes and statistical analysis We calculated sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy for MAS-based clinical assessment and outsourced CT reporting, with 95% confidence intervals (CIs). Categorical variables are presented as number (%), and continuous variables as mean and range. Analyses can be performed in SPSS or R; a two-sided p < 0.05 may be used where applicable. Large language model (ChatGPT, OpenAI) assistance was used for English language editing and manuscript structuring. No identifiable patient information was entered, and all outputs were reviewed and verified by the author. Participant flow and reference-standard classification are summarized in the STARD flow diagram (Fig. 1 ). During manuscript preparation, the author used a large language model (ChatGPT, OpenAI) to improve language and clarity. The author reviewed and edited the content and takes full responsibility for the work. Results A total of 573 adult patients were included. Baseline demographics are summarized in Table 1 . The mean age was 36.2 years (range 18–89), and 355 patients (62.0%) were male. Acute appendicitis was confirmed in 492 patients (85.9%). Negative appendectomy occurred in 81 patients (14.1%; 95% CI 11.5–17.1). Clinical assessment using MAS was categorized as positive in 450 patients (78.5%). Outsourced CT reports were categorized as positive in 517 patients (90.2%). Confusion matrices for clinical assessment and outsourced CT reporting are presented in Tables 2 and 3 . Diagnostic performance metrics with 95% CIs are summarized in Table 4 . Table 1 Demographic characteristics of the study population. Characteristic Value (n = 573) Male sex, n (%) 355 (62.0) Female sex, n (%) 218 (38.0) Age, mean (range), years 36.2 (18–89) Table 2 Clinical assessment (MAS-based) diagnostic outcomes versus reference standard. Outcome n True positive (clinical positive; appendicitis confirmed) 430 False positive (clinical positive; no appendicitis) 20 False negative (clinical negative; appendicitis confirmed) 62 True negative (clinical negative; no appendicitis) 61 Table 3 Outsourced CT report diagnostic outcomes versus reference standard. Outcome n True positive (CT positive; appendicitis confirmed) 480 False positive (CT positive; no appendicitis) 37 False negative (CT negative; appendicitis confirmed) 12 True negative (CT negative; no appendicitis) 44 Table 4 Diagnostic performance of clinical assessment and outsourced CT reporting. Metric Clinical assessment (MAS) % (95% CI) Outsourced CT report % (95% CI) Sensitivity 87.4% (84.2–90.0) 97.6% (95.8–98.6) Specificity 75.3% (64.9–83.4) 54.3% (43.5–64.7) PPV 95.6% (93.2–97.1) 92.8% (90.3–94.8) NPV 49.6% (40.9–58.3) 78.6% (66.2–87.3) Accuracy 85.7% (82.6–88.3) 91.4% (88.9–93.5) Note: Performance estimates are calculated within a surgically managed cohort with a high prevalence of appendicitis; predictive values and specificity may differ in unselected emergency department populations. Discussion In this retrospective study of adults who underwent appendectomy for suspected acute appendicitis, outsourced non-contrast CT reports demonstrated very high sensitivity and higher overall accuracy compared with MAS-based clinical assessment. However, outsourced CT reporting showed lower specificity in this cohort. Clinical assessment showed higher specificity but lower sensitivity, emphasizing that neither approach is sufficient as a stand-alone strategy in all cases. Our observed sensitivity for outsourced CT reporting (97.6%) is consistent with evidence that CT is generally highly sensitive for appendicitis in adults.[ 8 , 9 ] Our CT protocol was non-contrast; prior syntheses report that unenhanced standard-dose CT may have lower sensitivity than contrast-enhanced protocols, though specificity is less affected.[ 8 , 14 ] The high sensitivity in our cohort may also reflect spectrum effects and a cautious (rule-out) reporting style in an emergency surgical pathway, where missing appendicitis has high perceived risk. The specificity of outsourced CT reports (54.3%) was lower than expected from many CT accuracy studies.[ 8 , 9 ] This likely reflects study design: only operated patients were included, and the non-appendicitis group represents negative appendectomies rather than the full spectrum of CT-negative patients managed conservatively (verification bias).[ 13 ] Additionally, outsourced reporting can introduce inter-reader variability related to case volume, experience, reporting templates, and communication with the treating team.[ 10 – 12 ] In our data, CT categorized more patients as ‘positive’ than clinical assessment (90.2% vs 78.5%), which increases sensitivity but may contribute to a higher false-positive burden and potentially unnecessary surgery.[ 16 , 17 ] Standardized structured reports for suspected appendicitis and routine audit of discordant cases are pragmatic quality-improvement measures.[ 10 – 12 ] Potential impact on unnecessary surgery: In our cohort, 81 patients (14.1%) had no histopathologic appendicitis. Outsourced CT reports were positive in 37 of these patients (45.7%), compared with 20 (24.7%) classified as high-probability appendicitis by MAS. If a CT-positive report is weighted heavily in operative decision-making, this level of false-positive imaging could translate into a meaningful proportion of potentially avoidable appendectomies (37/573, 6.5% of all operations) and 17 more false-positive classifications than clinical assessment alone. This interpretation should be cautious: management decisions are multifactorial, and our surgically selected cohort likely inflates disease prevalence and underestimates specificity compared with an unselected emergency department population. Negative appendectomy is an important quality metric in appendicitis pathways. In our cohort, 14.1% of operated patients had no histologic appendicitis, which is within historical ranges but may be higher than rates reported in settings with routine CT use and standardized diagnostic pathways. Prior population-based analyses have described a decline in negative appendectomy during the era of widespread CT, although rates remain heterogeneous across institutions and patient subgroups.[ 16 , 17 ] When appendicitis is not confirmed, pathology may show a normal appendix or non-specific inflammatory changes (e.g., lymphoid hyperplasia or periappendicitis), and symptoms may reflect alternative diagnoses; documenting these findings can help refine false-positive patterns in outsourced reporting and guide local quality improvement. Clinical scoring remains valuable because it is immediate, repeatable, and can reduce reliance on imaging in clearly low- or high-probability cases.[ 2 , 6 , 7 ] Using a high-probability MAS threshold, clinical assessment in our cohort achieved sensitivity 87.4% and specificity 75.3%. This pattern mirrors prior work: higher score thresholds can ‘rule in’ appendicitis reasonably well, but lower scores do not reliably exclude it, particularly in women and older adults where alternative diagnoses are common.[ 6 , 7 ] For this reason, international guidelines recommend using clinical scores as part of a risk-stratification pathway rather than as a definitive diagnostic test.[ 2 ] From a practical standpoint, our findings support combined pathways: initial clinical risk stratification (e.g., MAS or AIR), selective imaging for intermediate-risk presentations or when complications or alternative diagnoses are suspected, and reassessment over time.[ 2 ] When CT is used, protocol choices (contrast vs non-contrast, standard-dose vs low-dose) and reporting practices influence downstream management; low-dose CT strategies have been shown to maintain diagnostic performance while reducing radiation exposure.[ 15 ] For centers using outsourced reporting, alignment on diagnostic criteria and turnaround targets, access to clinical information, and feedback loops between surgeons and radiologists may improve specificity without compromising safety.[ 10 – 12 ] Strengths include the relatively large sample size and the use of operative and histopathological findings as a reference standard. Limitations include the retrospective design; selection of only surgically managed patients (verification bias); lack of independent local re-interpretation of CT images; and potential incorporation bias if CT reports influenced the decision to operate.[ 13 ] We also did not capture external radiologist-level variables (experience, subspecialty training) or turnaround times, limiting exploration of sources of variability. Finally, the chosen MAS positivity threshold may affect performance estimates, and alternative cutoffs could be explored in sensitivity analyses. Additionally, CT studies were performed without IV contrast. Although unenhanced CT can be accurate, lack of IV contrast may reduce conspicuity in borderline cases and limit identification of alternative diagnoses, potentially encouraging overcalling and contributing to the lower specificity observed in our dataset.[ 8 , 9 ] Future studies should include all patients assessed for suspected appendicitis (including those discharged or managed non-operatively) and directly compare in-house versus outsourced interpretations with blinded re-reading and STARD-compliant reporting.[ 13 , 19 ] Linking diagnostic pathways to clinical outcomes (perforation rate, negative appendectomy, time to surgery, length of stay) would better quantify the practical impact of outsourcing.[ 16 , 17 ] Conclusions In a high-prevalence, surgically managed cohort, outsourced non-contrast CT reporting showed higher sensitivity and higher overall accuracy than MAS-based clinical assessment, but lower specificity. Optimized appendicitis pathways should integrate structured clinical scoring with imaging and implement quality assurance for outsourced reporting. Abbreviations CI confidence interval; CT computed tomography; FN false negative; FP false positive; MAS Modified Alvarado Score; NPV negative predictive value; PPV positive predictive value; STARD Standards for Reporting Diagnostic Accuracy Studies; TN true negative; TP true positive. Declarations CT: Computed tomography; MAS: Modified Alvarado Score; CI: Confidence interval; PPV: Positive predictive value; NPV: Negative predictive value; STARD: Standards for Reporting of Diagnostic Accuracy Studies. Authors' information: Not applicable. Acknowledgements: The author thanks the surgical and radiology teams involved in the routine clinical care of the patients. A large language model (ChatGPT, OpenAI) was used for language editing and clarity; the author takes full responsibility for the content. Authors' contributions: SG conceived and designed the study, curated the data, performed the statistical analyses, interpreted the results, drafted the manuscript, and approved the final version. Funding: No specific funding was received for this work. Competing interests: The author declares that he has no competing interests. Availability of data and materials: The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request, subject to institutional regulations. Consent for publication: Not applicable. Ethics approval and consent to participate: This study was approved by the relevant Institutional Ethics Committee (Approval No: [to be added], Date: [to be added]). The requirement for informed consent was waived due to the retrospective design and use of de-identified data. References Ferris M, Quan S, Kaplan BS, Molodecky N, Ball CG, Chernoff GW, et al. The global incidence of appendicitis: a systematic review of population-based studies. Ann Surg. 2017;266(2):237–41. https://doi.org/10.1097/SLA.0000000000002188 . Di Saverio S, Podda M, De Simone B, Ceresoli M, Augustin G, Gori A, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020;15(1):27. https://doi.org/10.1186/s13017-020-00306-3 . Lewis FR, Holcroft JW, Boey J, Dunphy E. Appendicitis: a critical review of diagnosis and treatment in 1,000 cases. Arch Surg. 1975;110(5):677–84. https://doi.org/10.1001/archsurg.1975.01360110223039 . Colson M, Skinner KA, Dunnington G. High negative appendectomy rates are no longer acceptable. Am J Surg. 1997;174(6):723–6. https://doi.org/10.1016/S0002-9610(97)00183-9 . Petroianu A. Diagnosis of acute appendicitis. Int J Surg. 2012;10(3):115–9. https://doi.org/10.1016/j.ijsu.2012.02.006 . Alvarado A. A practical score for the early diagnosis of acute appendicitis. Ann Emerg Med. 1986;15(5):557–64. https://doi.org/10.1016/S0196-0644(86)80993-3 . Kalan M, Talbot D, Cunliffe WJ, Rich AJ. Evaluation of the modified Alvarado score in the diagnosis of acute appendicitis: a prospective study. Ann R Coll Surg Engl. 1994;76(6):418–9. Rud B, Vejborg TS, Rappeport ED, Reitsma JB, Wille-Jørgensen P. Computed tomography for diagnosis of acute appendicitis in adults. Cochrane Database Syst Rev. 2019;2019(11):CD009977. https://doi.org/10.1002/14651858.CD009977.pub2 . Arruzza E, Rysavy M, Sahoo S, Benhamou D, Cadwallader S, Helm A, et al. Diagnostic accuracy of computed tomography and ultrasound for suspected acute appendicitis in adults: a systematic review and meta-analysis. Radiography (Lond). 2022;28(4):1092–101. https://doi.org/10.1016/j.radi.2022.08.006 . Hanna TN, Steenburg SD, Rosenkrantz AB, Pyatt RS Jr, Duszak R Jr, Friedberg EB. Emerging Challenges and Opportunities in the Evolution of Teleradiology. AJR Am J Roentgenol. 2020;215(6):1411–6. https://doi.org/10.2214/AJR.20.23007 . Wong WS. Outsourced teleradiology imaging services. J Am Coll Radiol. 2005;2(1):47–55. https://doi.org/10.1016/j.jacr.2004.09.010 . Howlett DC, Drinkwater K, Frost C, et al. The accuracy of interpretation of emergency abdominal CT: evaluation of major and minor discrepancy rates for provisional and addendum reports. Clin Radiol. 2017;72(1):41–6. https://doi.org/10.1016/j.crad.2016.10.008 . Bossuyt PM, Reitsma JB, Bruns DE, Gatsonis CA, Glasziou PP, Irwig L, et al. STARD 2015: an updated list of essential items for reporting diagnostic accuracy studies. BMJ. 2015;351:h5527. https://doi.org/10.1136/bmj.h5527 . Hlibczuk V, Dattaro JA, Jin Z, Falzon L, Brown MD. Diagnostic accuracy of noncontrast computed tomography for appendicitis in adults: a systematic review. Ann Emerg Med. 2010;55(1):51–e591. https://doi.org/10.1016/j.annemergmed.2009.06.509 . Kim K, Kim YH, Kim SY, et al. Low-dose abdominal CT for evaluating suspected appendicitis. N Engl J Med. 2012;366(17):1596–605. https://doi.org/10.1056/NEJMoa1110734 . Raja AS, Wright C, Sodickson AD, Zane RD, Schiff GD, Hanson R, et al. Negative appendectomy rate in the era of CT: an 18-year perspective. Radiology. 2010;256(2):460–5. https://doi.org/10.1148/radiol.10091570 . Guller U, Rosella L, McCall J, et al. Negative appendicectomy and perforation rates in patients undergoing appendicectomy. Br J Surg. 2011;98(4):589–95. https://doi.org/10.1002/bjs.7406 . Atema JJ, van Rossem CC, Leeuwenburgh MMN, et al. Scoring system to distinguish uncomplicated from complicated acute appendicitis. Br J Surg. 2015;102(8):979–90. https://doi.org/10.1002/bjs.9835 . Cohen JF, Korevaar DA, Gatsonis CA, et al. STARD 2015 guidelines for reporting diagnostic accuracy studies: explanation and elaboration. BMJ Open. 2016;6(11):e012799. https://doi.org/10.1136/bmjopen-2016-012799 . Wilkinson M, et al. Accuracy of outsourced radiology reports in emergency surgical care. Cureus. 2024;16(11):e72852. https://doi.org/10.7759/cureus.72852 . Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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13:33:46","extension":"xml","order_by":11,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":69742,"visible":true,"origin":"","legend":"","description":"","filename":"5362c2b101754940bda50c0e97c9d1181structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-8476177/v1/f60ad59a6c6e07ec725823d7.xml"},{"id":99636492,"identity":"8a1b789d-2ce6-4941-a460-e6d0822c9d9a","added_by":"auto","created_at":"2026-01-06 17:13:32","extension":"html","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":77830,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-8476177/v1/74c4248229242b88dfae80eb.html"},{"id":99636480,"identity":"71fa897e-095a-4cf1-8378-3b164cd0ee50","added_by":"auto","created_at":"2026-01-06 17:13:32","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":302482,"visible":true,"origin":"","legend":"\u003cp\u003eSTARD flow diagram of participant inclusion and reference-standard classification.\u003c/p\u003e","description":"","filename":"Figure1STARDFlow.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8476177/v1/7e6e028f5a6be5c0f446c38e.jpeg"},{"id":108760078,"identity":"f123949a-783a-4e9e-9339-0df977c490cd","added_by":"auto","created_at":"2026-05-08 06:26:20","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":511917,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8476177/v1/0de5a041-2683-40b9-ac76-fdae45b00bd8.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Outsourced CT Reporting versus Clinical Assessment for Diagnosing Acute Appendicitis: A Retrospective Diagnostic Accuracy Study","fulltext":[{"header":"Background","content":"\u003cp\u003eAcute appendicitis is among the most frequent causes of acute abdominal pain requiring urgent surgical evaluation and remains a major driver of emergency department admissions and appendectomy worldwide.[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e] Despite being a common diagnosis, its clinical presentation can be nonspecific, overlapping with gynecologic, urinary, and gastrointestinal conditions, particularly in women and older adults.[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/p\u003e \u003cp\u003eHistorically, clinicians tolerated relatively high negative appendectomy rates to avoid missed or perforated appendicitis; however, the availability of clinical scoring systems and cross-sectional imaging has shifted modern practice toward greater diagnostic precision.[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e] Clinical scores such as the Alvarado and modified Alvarado scores (MAS) aggregate symptoms, signs, and basic laboratory parameters into a simple bedside probability estimate and can help standardize decision-making.[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]\u003c/p\u003e \u003cp\u003eComputed tomography (CT) is widely used when the diagnosis is uncertain or when complications and alternative diagnoses must be considered.[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] Systematic reviews report high diagnostic performance of CT for appendicitis in adults, although accuracy depends on patient selection, protocol (contrast vs non-contrast), and reader experience.[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] In many institutions, radiology services\u0026mdash;especially out-of-hours coverage\u0026mdash;are partially or fully provided via teleradiology/outsourcing models. While teleradiology can improve timeliness and access, discordant interpretations and variability in reporting quality remain important safety and governance concerns.[\u003cspan additionalcitationids=\"CR11\" citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/p\u003e \u003cp\u003eIn this context, understanding how outsourced CT reports perform in real-world surgical pathways is important. The primary aim of this study was to assess and compare the diagnostic accuracy of outsourced non-contrast CT reports and clinical assessment using MAS for detecting acute appendicitis, using operative and histopathological findings as the reference standard.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e \u003cstrong\u003eStudy design and reporting\u003c/strong\u003e \u003cp\u003eThis retrospective diagnostic accuracy study was conducted at Ağrı Training and Research Hospital (Ağrı, T\u0026uuml;rkiye) and is reported in line with STARD 2015 where applicable.[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eParticipants\u003c/strong\u003e \u003cp\u003eConsecutive adult patients (\u0026ge;\u0026thinsp;18 years) who underwent appendectomy for suspected acute appendicitis between January 2020 and January 2025 were screened. The analyzed cohort consisted of patients with complete clinical assessment, a preoperative non-contrast abdominal CT performed during the index emergency visit, and an available operative and/or histopathological final diagnosis.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eInclusion criteria\u003c/strong\u003e \u003cp\u003e(i) clinical suspicion of acute appendicitis; (ii) preoperative non-contrast CT performed at our institution; (iii) an outsourced radiology report available for the CT study; (iv) appendectomy performed during the index admission; and (v) intraoperative findings and/or histopathology available.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eExclusion criteria\u003c/strong\u003e \u003cp\u003epregnancy, missing key clinical or imaging data, inadequate/poor-quality CT imaging, and prior appendectomy.\u003c/p\u003e \u003c/p\u003e \u003cp\u003eClinical assessment (index test 1): Clinical probability was assessed using the Modified Alvarado Score (MAS), incorporating migration of pain, right lower quadrant tenderness, anorexia, nausea/vomiting, fever, and leukocytosis.[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] Consistent with common clinical practice, MAS in the high-probability range (\u0026ge;\u0026thinsp;7) was categorized as \u0026lsquo;clinically positive\u0026rsquo;; lower scores were categorized as \u0026lsquo;clinically negative\u0026rsquo;.\u003c/p\u003e \u003cp\u003eCT acquisition and outsourced reporting (index test 2): Non-contrast abdominal CT scans were acquired using an Alexion CT scanner (Canon Medical Systems, Otawara, Japan). Scans were obtained in the supine position without intravenous or oral contrast, and images were typically reconstructed at 3\u0026ndash;5 mm slice thickness with multiplanar reformations (coronal and sagittal) according to the institutional emergency abdomen protocol. CT images were interpreted by external radiology providers as part of an outsourced reporting workflow. For this analysis, CT was categorized as positive when the final report impression favored acute appendicitis and negative otherwise. CT images were not re-interpreted by local radiologists for study purposes.\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eReference standard\u003c/strong\u003e \u003cp\u003eThe final diagnosis of acute appendicitis was defined by intraoperative macroscopic findings consistent with acute appendicitis and/or histopathological confirmation of appendicitis. Negative appendectomy was defined as absence of appendicitis on histopathology.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eOutcomes and statistical analysis\u003c/strong\u003e \u003cp\u003eWe calculated sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy for MAS-based clinical assessment and outsourced CT reporting, with 95% confidence intervals (CIs). Categorical variables are presented as number (%), and continuous variables as mean and range. Analyses can be performed in SPSS or R; a two-sided p\u0026thinsp;\u0026lt;\u0026thinsp;0.05 may be used where applicable.\u003c/p\u003e \u003c/p\u003e \u003cp\u003eLarge language model (ChatGPT, OpenAI) assistance was used for English language editing and manuscript structuring. No identifiable patient information was entered, and all outputs were reviewed and verified by the author.\u003c/p\u003e \u003cp\u003eParticipant flow and reference-standard classification are summarized in the STARD flow diagram (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eDuring manuscript preparation, the author used a large language model (ChatGPT, OpenAI) to improve language and clarity. The author reviewed and edited the content and takes full responsibility for the work.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 573 adult patients were included. Baseline demographics are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The mean age was 36.2 years (range 18\u0026ndash;89), and 355 patients (62.0%) were male.\u003c/p\u003e \u003cp\u003eAcute appendicitis was confirmed in 492 patients (85.9%). Negative appendectomy occurred in 81 patients (14.1%; 95% CI 11.5\u0026ndash;17.1).\u003c/p\u003e \u003cp\u003eClinical assessment using MAS was categorized as positive in 450 patients (78.5%). Outsourced CT reports were categorized as positive in 517 patients (90.2%).\u003c/p\u003e \u003cp\u003eConfusion matrices for clinical assessment and outsourced CT reporting are presented in Tables\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e and \u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. Diagnostic performance metrics with 95% CIs are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDemographic characteristics of the study population.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCharacteristic\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eValue (n\u0026thinsp;=\u0026thinsp;573)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale sex, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e355 (62.0)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale sex, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e218 (38.0)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge, mean (range), years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e36.2 (18\u0026ndash;89)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eClinical assessment (MAS-based) diagnostic outcomes versus reference standard.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOutcome\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003en\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTrue positive (clinical positive; appendicitis confirmed)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e430\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFalse positive (clinical positive; no appendicitis)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFalse negative (clinical negative; appendicitis confirmed)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e62\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTrue negative (clinical negative; no appendicitis)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e61\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eOutsourced CT report diagnostic outcomes versus reference standard.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOutcome\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003en\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTrue positive (CT positive; appendicitis confirmed)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e480\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFalse positive (CT positive; no appendicitis)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e37\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFalse negative (CT negative; appendicitis confirmed)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTrue negative (CT negative; no appendicitis)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e44\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDiagnostic performance of clinical assessment and outsourced CT reporting.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMetric\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eClinical assessment (MAS) % (95% CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eOutsourced CT report % (95% CI)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSensitivity\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e87.4% (84.2\u0026ndash;90.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e97.6% (95.8\u0026ndash;98.6)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSpecificity\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e75.3% (64.9\u0026ndash;83.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e54.3% (43.5\u0026ndash;64.7)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePPV\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e95.6% (93.2\u0026ndash;97.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e92.8% (90.3\u0026ndash;94.8)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNPV\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e49.6% (40.9\u0026ndash;58.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e78.6% (66.2\u0026ndash;87.3)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAccuracy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e85.7% (82.6\u0026ndash;88.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e91.4% (88.9\u0026ndash;93.5)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cem\u003eNote: Performance estimates are calculated within a surgically managed cohort with a high prevalence of appendicitis; predictive values and specificity may differ in unselected emergency department populations.\u003c/em\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn this retrospective study of adults who underwent appendectomy for suspected acute appendicitis, outsourced non-contrast CT reports demonstrated very high sensitivity and higher overall accuracy compared with MAS-based clinical assessment. However, outsourced CT reporting showed lower specificity in this cohort. Clinical assessment showed higher specificity but lower sensitivity, emphasizing that neither approach is sufficient as a stand-alone strategy in all cases.\u003c/p\u003e \u003cp\u003eOur observed sensitivity for outsourced CT reporting (97.6%) is consistent with evidence that CT is generally highly sensitive for appendicitis in adults.[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] Our CT protocol was non-contrast; prior syntheses report that unenhanced standard-dose CT may have lower sensitivity than contrast-enhanced protocols, though specificity is less affected.[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e] The high sensitivity in our cohort may also reflect spectrum effects and a cautious (rule-out) reporting style in an emergency surgical pathway, where missing appendicitis has high perceived risk.\u003c/p\u003e \u003cp\u003eThe specificity of outsourced CT reports (54.3%) was lower than expected from many CT accuracy studies.[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] This likely reflects study design: only operated patients were included, and the non-appendicitis group represents negative appendectomies rather than the full spectrum of CT-negative patients managed conservatively (verification bias).[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] Additionally, outsourced reporting can introduce inter-reader variability related to case volume, experience, reporting templates, and communication with the treating team.[\u003cspan additionalcitationids=\"CR11\" citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] In our data, CT categorized more patients as \u0026lsquo;positive\u0026rsquo; than clinical assessment (90.2% vs 78.5%), which increases sensitivity but may contribute to a higher false-positive burden and potentially unnecessary surgery.[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] Standardized structured reports for suspected appendicitis and routine audit of discordant cases are pragmatic quality-improvement measures.[\u003cspan additionalcitationids=\"CR11\" citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/p\u003e \u003cp\u003ePotential impact on unnecessary surgery: In our cohort, 81 patients (14.1%) had no histopathologic appendicitis. Outsourced CT reports were positive in 37 of these patients (45.7%), compared with 20 (24.7%) classified as high-probability appendicitis by MAS. If a CT-positive report is weighted heavily in operative decision-making, this level of false-positive imaging could translate into a meaningful proportion of potentially avoidable appendectomies (37/573, 6.5% of all operations) and 17 more false-positive classifications than clinical assessment alone. This interpretation should be cautious: management decisions are multifactorial, and our surgically selected cohort likely inflates disease prevalence and underestimates specificity compared with an unselected emergency department population.\u003c/p\u003e \u003cp\u003eNegative appendectomy is an important quality metric in appendicitis pathways. In our cohort, 14.1% of operated patients had no histologic appendicitis, which is within historical ranges but may be higher than rates reported in settings with routine CT use and standardized diagnostic pathways. Prior population-based analyses have described a decline in negative appendectomy during the era of widespread CT, although rates remain heterogeneous across institutions and patient subgroups.[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] When appendicitis is not confirmed, pathology may show a normal appendix or non-specific inflammatory changes (e.g., lymphoid hyperplasia or periappendicitis), and symptoms may reflect alternative diagnoses; documenting these findings can help refine false-positive patterns in outsourced reporting and guide local quality improvement.\u003c/p\u003e \u003cp\u003eClinical scoring remains valuable because it is immediate, repeatable, and can reduce reliance on imaging in clearly low- or high-probability cases.[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] Using a high-probability MAS threshold, clinical assessment in our cohort achieved sensitivity 87.4% and specificity 75.3%. This pattern mirrors prior work: higher score thresholds can \u0026lsquo;rule in\u0026rsquo; appendicitis reasonably well, but lower scores do not reliably exclude it, particularly in women and older adults where alternative diagnoses are common.[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] For this reason, international guidelines recommend using clinical scores as part of a risk-stratification pathway rather than as a definitive diagnostic test.[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]\u003c/p\u003e \u003cp\u003eFrom a practical standpoint, our findings support combined pathways: initial clinical risk stratification (e.g., MAS or AIR), selective imaging for intermediate-risk presentations or when complications or alternative diagnoses are suspected, and reassessment over time.[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e] When CT is used, protocol choices (contrast vs non-contrast, standard-dose vs low-dose) and reporting practices influence downstream management; low-dose CT strategies have been shown to maintain diagnostic performance while reducing radiation exposure.[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] For centers using outsourced reporting, alignment on diagnostic criteria and turnaround targets, access to clinical information, and feedback loops between surgeons and radiologists may improve specificity without compromising safety.[\u003cspan additionalcitationids=\"CR11\" citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/p\u003e \u003cp\u003eStrengths include the relatively large sample size and the use of operative and histopathological findings as a reference standard. Limitations include the retrospective design; selection of only surgically managed patients (verification bias); lack of independent local re-interpretation of CT images; and potential incorporation bias if CT reports influenced the decision to operate.[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] We also did not capture external radiologist-level variables (experience, subspecialty training) or turnaround times, limiting exploration of sources of variability. Finally, the chosen MAS positivity threshold may affect performance estimates, and alternative cutoffs could be explored in sensitivity analyses. Additionally, CT studies were performed without IV contrast. Although unenhanced CT can be accurate, lack of IV contrast may reduce conspicuity in borderline cases and limit identification of alternative diagnoses, potentially encouraging overcalling and contributing to the lower specificity observed in our dataset.[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/p\u003e \u003cp\u003eFuture studies should include all patients assessed for suspected appendicitis (including those discharged or managed non-operatively) and directly compare in-house versus outsourced interpretations with blinded re-reading and STARD-compliant reporting.[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e] Linking diagnostic pathways to clinical outcomes (perforation rate, negative appendectomy, time to surgery, length of stay) would better quantify the practical impact of outsourcing.[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eIn a high-prevalence, surgically managed cohort, outsourced non-contrast CT reporting showed higher sensitivity and higher overall accuracy than MAS-based clinical assessment, but lower specificity. Optimized appendicitis pathways should integrate structured clinical scoring with imaging and implement quality assurance for outsourced reporting.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eCI confidence interval; CT computed tomography; FN false negative; FP false positive; MAS Modified Alvarado Score; NPV negative predictive value; PPV positive predictive value; STARD Standards for Reporting Diagnostic Accuracy Studies; TN true negative; TP true positive.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eCT: Computed tomography; MAS: Modified Alvarado Score; CI: Confidence interval; PPV: Positive predictive value; NPV: Negative predictive value; STARD: Standards for Reporting of Diagnostic Accuracy Studies.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; information:\u0026nbsp;\u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements:\u0026nbsp;\u003c/strong\u003eThe author thanks the surgical and radiology teams involved in the routine clinical care of the patients. A large language model (ChatGPT, OpenAI) was used for language editing and clarity; the author takes full responsibility for the content.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions:\u0026nbsp;\u003c/strong\u003eSG conceived and designed the study, curated the data, performed the statistical analyses, interpreted the results, drafted the manuscript, and approved the final version.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u0026nbsp;\u003c/strong\u003eNo specific funding was received for this work.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests:\u0026nbsp;\u003c/strong\u003eThe author declares that he has no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials:\u0026nbsp;\u003c/strong\u003eThe datasets used and/or analysed during the current study are available from the corresponding author on reasonable request, subject to institutional regulations.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication:\u0026nbsp;\u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate:\u0026nbsp;\u003c/strong\u003eThis study was approved by the relevant Institutional Ethics Committee (Approval No: [to be added], Date: [to be added]). The requirement for informed consent was waived due to the retrospective design and use of de-identified data.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eFerris M, Quan S, Kaplan BS, Molodecky N, Ball CG, Chernoff GW, et al. The global incidence of appendicitis: a systematic review of population-based studies. Ann Surg. 2017;266(2):237\u0026ndash;41. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1097/SLA.0000000000002188\u003c/span\u003e\u003cspan address=\"10.1097/SLA.0000000000002188\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDi Saverio S, Podda M, De Simone B, Ceresoli M, Augustin G, Gori A, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020;15(1):27. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1186/s13017-020-00306-3\u003c/span\u003e\u003cspan address=\"10.1186/s13017-020-00306-3\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLewis FR, Holcroft JW, Boey J, Dunphy E. Appendicitis: a critical review of diagnosis and treatment in 1,000 cases. Arch Surg. 1975;110(5):677\u0026ndash;84. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1001/archsurg.1975.01360110223039\u003c/span\u003e\u003cspan address=\"10.1001/archsurg.1975.01360110223039\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eColson M, Skinner KA, Dunnington G. High negative appendectomy rates are no longer acceptable. Am J Surg. 1997;174(6):723\u0026ndash;6. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/S0002-9610(97)00183-9\u003c/span\u003e\u003cspan address=\"10.1016/S0002-9610(97)00183-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePetroianu A. Diagnosis of acute appendicitis. Int J Surg. 2012;10(3):115\u0026ndash;9. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ijsu.2012.02.006\u003c/span\u003e\u003cspan address=\"10.1016/j.ijsu.2012.02.006\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAlvarado A. A practical score for the early diagnosis of acute appendicitis. Ann Emerg Med. 1986;15(5):557\u0026ndash;64. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/S0196-0644(86)80993-3\u003c/span\u003e\u003cspan address=\"10.1016/S0196-0644(86)80993-3\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKalan M, Talbot D, Cunliffe WJ, Rich AJ. Evaluation of the modified Alvarado score in the diagnosis of acute appendicitis: a prospective study. Ann R Coll Surg Engl. 1994;76(6):418\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRud B, Vejborg TS, Rappeport ED, Reitsma JB, Wille-J\u0026oslash;rgensen P. Computed tomography for diagnosis of acute appendicitis in adults. Cochrane Database Syst Rev. 2019;2019(11):CD009977. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1002/14651858.CD009977.pub2\u003c/span\u003e\u003cspan address=\"10.1002/14651858.CD009977.pub2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eArruzza E, Rysavy M, Sahoo S, Benhamou D, Cadwallader S, Helm A, et al. Diagnostic accuracy of computed tomography and ultrasound for suspected acute appendicitis in adults: a systematic review and meta-analysis. Radiography (Lond). 2022;28(4):1092\u0026ndash;101. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.radi.2022.08.006\u003c/span\u003e\u003cspan address=\"10.1016/j.radi.2022.08.006\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHanna TN, Steenburg SD, Rosenkrantz AB, Pyatt RS Jr, Duszak R Jr, Friedberg EB. Emerging Challenges and Opportunities in the Evolution of Teleradiology. AJR Am J Roentgenol. 2020;215(6):1411\u0026ndash;6. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.2214/AJR.20.23007\u003c/span\u003e\u003cspan address=\"10.2214/AJR.20.23007\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWong WS. Outsourced teleradiology imaging services. J Am Coll Radiol. 2005;2(1):47\u0026ndash;55. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jacr.2004.09.010\u003c/span\u003e\u003cspan address=\"10.1016/j.jacr.2004.09.010\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHowlett DC, Drinkwater K, Frost C, et al. The accuracy of interpretation of emergency abdominal CT: evaluation of major and minor discrepancy rates for provisional and addendum reports. Clin Radiol. 2017;72(1):41\u0026ndash;6. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.crad.2016.10.008\u003c/span\u003e\u003cspan address=\"10.1016/j.crad.2016.10.008\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBossuyt PM, Reitsma JB, Bruns DE, Gatsonis CA, Glasziou PP, Irwig L, et al. STARD 2015: an updated list of essential items for reporting diagnostic accuracy studies. BMJ. 2015;351:h5527. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1136/bmj.h5527\u003c/span\u003e\u003cspan address=\"10.1136/bmj.h5527\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHlibczuk V, Dattaro JA, Jin Z, Falzon L, Brown MD. Diagnostic accuracy of noncontrast computed tomography for appendicitis in adults: a systematic review. Ann Emerg Med. 2010;55(1):51\u0026ndash;e591. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.annemergmed.2009.06.509\u003c/span\u003e\u003cspan address=\"10.1016/j.annemergmed.2009.06.509\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim K, Kim YH, Kim SY, et al. Low-dose abdominal CT for evaluating suspected appendicitis. N Engl J Med. 2012;366(17):1596\u0026ndash;605. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1056/NEJMoa1110734\u003c/span\u003e\u003cspan address=\"10.1056/NEJMoa1110734\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRaja AS, Wright C, Sodickson AD, Zane RD, Schiff GD, Hanson R, et al. Negative appendectomy rate in the era of CT: an 18-year perspective. Radiology. 2010;256(2):460\u0026ndash;5. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1148/radiol.10091570\u003c/span\u003e\u003cspan address=\"10.1148/radiol.10091570\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGuller U, Rosella L, McCall J, et al. Negative appendicectomy and perforation rates in patients undergoing appendicectomy. Br J Surg. 2011;98(4):589\u0026ndash;95. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1002/bjs.7406\u003c/span\u003e\u003cspan address=\"10.1002/bjs.7406\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAtema JJ, van Rossem CC, Leeuwenburgh MMN, et al. Scoring system to distinguish uncomplicated from complicated acute appendicitis. Br J Surg. 2015;102(8):979\u0026ndash;90. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1002/bjs.9835\u003c/span\u003e\u003cspan address=\"10.1002/bjs.9835\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCohen JF, Korevaar DA, Gatsonis CA, et al. STARD 2015 guidelines for reporting diagnostic accuracy studies: explanation and elaboration. BMJ Open. 2016;6(11):e012799. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1136/bmjopen-2016-012799\u003c/span\u003e\u003cspan address=\"10.1136/bmjopen-2016-012799\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWilkinson M, et al. Accuracy of outsourced radiology reports in emergency surgical care. Cureus. 2024;16(11):e72852. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.7759/cureus.72852\u003c/span\u003e\u003cspan address=\"10.7759/cureus.72852\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"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":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"acute appendicitis, computed tomography, teleradiology, outsourced radiology, Modified Alvarado Score, diagnostic accuracy","lastPublishedDoi":"10.21203/rs.3.rs-8476177/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8476177/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eOutsourced radiology interpretation is increasingly used to maintain emergency imaging workflows, yet its diagnostic performance in suspected acute appendicitis remains uncertain. We compared outsourced non-contrast CT reporting with bedside clinical assessment in a surgically managed cohort.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThis retrospective diagnostic accuracy study included adults (\u0026ge;\u0026thinsp;18 years) who underwent appendectomy for suspected acute appendicitis. Index tests were outsourced CT reports and the attending surgeon\u0026rsquo;s preoperative clinical assessment. The reference standard was intraoperative and/or histopathological diagnosis. Sensitivity, specificity and accuracy were calculated with 95% confidence intervals.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eAmong 573 patients, appendicitis was confirmed in 492 (85.9%) and negative appendectomy occurred in 81 (14.1%). Outsourced CT reporting yielded sensitivity 87.4% (95% CI 84.1\u0026ndash;90.1), specificity 75.3% (95% CI 64.8\u0026ndash;83.6) and accuracy 91.4%. Clinical assessment yielded sensitivity 97.6% (95% CI 95.8\u0026ndash;98.6), specificity 54.3% (95% CI 43.6\u0026ndash;64.5) and accuracy 85.7%.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eIn this cohort, outsourced non-contrast CT reports showed higher specificity than clinical assessment, but clinically meaningful false-positive reporting may contribute to potentially avoidable appendectomies. Quality assurance and standardized protocols may improve performance in outsourced services.\u003c/p\u003e\u003ch2\u003eTrial registration:\u003c/h2\u003e \u003cp\u003eNot applicable.\u003c/p\u003e","manuscriptTitle":"Outsourced CT Reporting versus Clinical Assessment for Diagnosing Acute Appendicitis: A Retrospective Diagnostic Accuracy Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-06 17:13:27","doi":"10.21203/rs.3.rs-8476177/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"b1597693-42c5-4742-ac90-3ab5a6643728","owner":[],"postedDate":"January 6th, 2026","published":true,"recentEditorialEvents":[{"type":"decision","content":"Rejected","date":"2026-05-08T06:14:33+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-05-06T09:30:39+00:00","index":110,"fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-05-08T06:25:51+00:00","versionOfRecord":[],"versionCreatedAt":"2026-01-06 17:13:27","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8476177","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8476177","identity":"rs-8476177","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}