Rising Public Cost of Preterm Infant Hospitalization: A nationwide observational study in South Korea

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We analyze hospitalization costs covered by national public insurance for preterm infants. Methods: Population-based data, obtained from the National Health Insurance Service (NHIS), which is operated by the Health Insurance Review and Assessment Service, were used for the study. Preterm births from January 1, 2008 to December 31, 2020 were included, using International Classification of Diseases and Related Health Problems, 10 th edition (P0.72, extremely preterm <28 weeks gestational age, P07.3, non-extremely preterm). The primary outcomes related to cost from the first hospitalization due to preterm births and medication, and laboratory, radiological, and functional tests by gestational age and birth weight. Additionally, we assessed the readmission rates of preterm infants and the associated medical costs. Results: A total of 5,312,886 live infants were born, of which 90,575 were claimed as preterm birth hospitalization. The total medical cost per patient increased almost three-fold from $7,390.90 to $20,209.59 from 2008 to 2020; for the extremely preterm group, it increased four-fold ($13,961.03 to $55,984.47 $). The readmission rate within 90 days of discharge was 62.5%; however, a greater proportion of the extremely preterm, as compared to the non-extremely preterm (16.1% vs. 8.32%, P < 0.001) group was readmitted within 30 days,. The extremely preterm group also incurred higher costs associated with readmission (mean $4293.8 vs. $2975.4, P < 0.001). Conclusion: This study reveals not only the increase in preterm birth rate in South Korea, but also in the associated medical costs. Further attention should be paid to efficient resource allocation at the national level to relieve the medical burden of preterm births. Health sciences/Medical research/Epidemiology Health sciences/Health care/Health policy Prematurity Cost health insurance hospitalization preterm birth Figures Figure 1 Figure 2 INTRODUCTION Neonatal diseases account for the largest share of pediatric hospital stays and costs in the United States. 1 Of these, premature birth is still the leading cause of neonatal mortality and morbidities in developed countries. 2 The rate of preterm birth in the United States increased steadily to 12.3% in 2004. 3 , 4 The global burden of disease reported that neonatal disorders, still one of the leading causes of death among children under five years, accounted for 2.1–2.2 million deaths in 2015. 5 Some worldwide cohort studies reported that the increasing trend of preterm birth has been mitigated. 6 – 8 However, our study group reported, in a previous study, that even during COVID-19 pandemics, the preterm birth rate in South Korea increased consistently, until recently. 9 Additionally, hospital fees per single preterm infant have also increased, according to annual reports from the United States. 2 Korean data have not been investigated; however, we can assume that trends in neonatal practice in Korea have moved commensurately with technical advancement. National health insurance coverage should be considered as one of the factors for total expenditure on hospitalization, as financial accessibility has increased the availability of medical practice and examinations. The objective of this study is to estimate the preterm infant hospitalization costs covered by national public insurance in South Korea, and to compare the yearly changes from the data and indicated annual events, such as changes in the government’s insurance coverage policies. METHODS Data Source We used population-based data from the National Health Insurance Service (NHIS), operated by the Health Insurance Review and Assessment Service, a universal health reimbursement insurer that covers 98% of the Korean population. The database includes information on not only the clinical characteristics of the cohort, but also the prescribed diagnostic tests and treatments covered by the NHIS. The information from the first inpatient claims data, registered with diagnostic codes related to preterm births, was used. Study design This is a retrospective cohort study to assess the trends in healthcare utilization and medical costs associated with preterm births, covered by the NHIS from January 1, 2007, to February 28, 2021. Neonates, who were registered with diagnostic codes related to prematurity in 2007, were excluded as a washout period owing to possible delays in receipt registration. Additionally, because the 2021 data included information for only two months, we excluded that year from the study as well. Further, multiple claims data from the same patient were excluded to include only the claims data for the first prematurity-related hospitalization. The outcomes on length of hospitalization and medical costs using operational definitions, such as medication and laboratory, radiological, and functional examinations, were analyzed using gestational age (GA) and birth weight. Study population We included those with prematurity-related codes of International Classification of Diseases and Related Health Problems , 10th edition (ICD-10), and included multiple births. As extreme preterm birth or birth at < 28 weeks of GA is associated with higher mortality and morbidity, we categorized prematurity into extremely preterm (P07.2 on ICD-10) and non-extremely preterm (P07.3 on ICD-10). Statistical analysis We divided preterm infants into extreme (less than 28 gestational weeks) and non-extreme (gestational weeks between 28 and 37) preterm birth groups. Thereafter, we compared these two groups according to baseline characteristics, length of hospitalization, medical costs, and proportion of re-hospitalization. Categorical variables were expressed as frequencies and percentages (%) and were compared using the chi-square test. Continuous variables were expressed as mean and standard deviation (SD) or medians (first quartile(Q1), third quartile(Q3)), and compared using the independent t-test or Wilcoxon rank-sum test, respectively. Statistical significance was defined as a two-sided P- value of < 0.05. Statistical analyses were performed using the SAS Enterprise Guide version 7.1 (SAS Institute Inc., Cary, NC, USA). Ethics statement This study was conducted in accordance with the World Medical Association and the Declaration of Helsinki, and the Institutional Review Board (IRB) of Severance Hospital, Yonsei University, Seoul, Republic of Korea (No. 4-2021-0416) approved the study. The IRB has waived the requirement for informed consent due to the minimal-risk nature of the research. Data availability The data that support the findings of this study are available from National Health Insurance Service (NHIS), operated by the Health Insurance Review and Assessment Service of Government of Republic of Korea. But restrictions apply to the availability of these data, which were used under license for the current study, and so are not publicly available. Data are however available from the authors upon reasonable request and with permission of NHIS. RESULTS From 2008 to 2020, a total of 5,312,886 live birth infants gave birth in total nation. Among which 137,214 infants were claimed as diagnosis of premature born infant. We excluded 46,639 infants who were only claimed as outpatient clinics and have not been hospitalized (Fig. 1 ). A slight male predominance was observed in preterm neonates (54.0%, P < 0.001). The number of preterm births more than doubled from 3,722 (4%) in 2008 to 9,009 (9.9%) in 2020 ( P < 0.001), with a similar frequency across the seasons. About 99% of the preterm births, were covered by the NHIS, and 47% of preterm birth deliveries were observed in the main urban areas in Korea, such as Seoul and the suburban Gyeonggi province. Table 1 shows the characteristics of preterm births. Table 1 Baseline characteristics of preterm births by gestational age Extremely Preterm Infants (less than 28 weeks) Non-extreme Preterm Infants (28 to 37 gestational weeks) Total n % n % p value N (%) 90575 7380 83195 Sex N (%) Male 48928 3831 51.9 45097 54.2 0.0001 Female 41647 3549 48.1 38098 45.8 Birth year, N (%) < 0.001 2008 3733 312 4.2 3421 4.1 2009 4128 317 4.3 3811 4.6 2010 4779 318 4.3 4461 5.4 2011 5291 591 8.0 4700 5.6 2012 5952 697 9.4 5255 6.3 2013 6761 660 8.9 6101 7.3 2014 7344 713 9.7 6631 8.0 2015 7928 752 10.2 7176 8.6 2016 8252 678 9.2 7574 9.1 2017 9090 589 8.0 8501 10.2 2018 9134 589 8.0 8545 10.3 2019 9174 587 8.0 8587 10.3 2020 9009 577 7.8 8432 10.1 Season, N (%) Winter (Dec-Feb) 22778 1831 24.8 20947 25.2 0.6122 Spring (Mar-May) 22075 1769 24.0 20306 24.4 Summer (Jun-Aug) 22996 1895 25.7 21101 25.4 Autumn (Sep-Nov) 22726 1885 25.5 20841 25.1 Delivery payment source, N (%) NHIS 89706 7326 99.3 82380 99.0 0.0363 Medical aid 869 54 0.7 815 1.0 Delivery location, N (%) # Seoul, Gyeonggi-do 42562 3606 49.1 38956 47.5 < 0.001 Metropolitan cities 29905 2599 35.4 27306 33.3 Other (rural area) 16932 1136 15.5 15796 19.3 Medical burden of preterm singleton birth hospitalization We analyzed the medical costs associated with hospitalization for preterm births at 28 weeks GA and birth weight. The median length of hospitalization for extremely preterm singleton neonates was almost twice that for preterm infants older than 28 weeks GA (40 days, IQR 28–60 vs. 21 days, IQR 11–35, P < 0.001) (Table 2 ). The mean medical cost per patient was higher for the extremely preterm group than for those born before 28 weeks ( $ 33,872.2, SD $ 24,369.2 vs. $ 12,713, SD $ 13,078.8). When the cost was categorized according to medication and type of diagnostic examination, the former accounted for the majority of the cost in both, extremely preterm and other preterm neonates ( $ 2383.5, SD $ 1486.2 vs. $ 802.0, SD $ 1136.1), but at a slightly higher proportion in the extremely preterm group (43.2% vs. 37.4%, P < 0.001). Moreover, the cost of laboratory examinations was the major source of expenses for diagnostic tests, such as radiological and functional examinations, in both the GA groups (63.7% vs. 59.4%, P < 0.001). Table 2 Medical burden of birth hospitalization for preterm singletons by gestational age, 2008–2020 Extremely Preterm Infants Non-extreme Preterm Infants p value bw < 1000g 1000g ≤ bw < 1500g 1500g ≤ bw < 2500g p value Average length of hospitalization, days Median (Q1, Q3) 40 (28, 60) 21 (11,35) < 0.001 40 (29, 59) 40 (30, 53) 20 (13, 30) < 0.001 Total direct medical cost, USD Mean (SD) 33872.23 (24369.23) 12713.66 (13078.77) < 0.001 35805.78 (23967.02) 24900.19 (15555.44) 12098.89 (10418.92) < 0.001 Median (Q1, Q3) 29101.33 (16460.45, 45543.52) 9181.53 (3590.14, 17554.82) < 0.001 31194.74 (18722.12, 47137.71) 22025.08 (13993.52, 32670.32) 9807.06 (5092.76, 16384.92) < 0.001 Comparison of components of direct medical costs per patient, USD Medication n = 7348 n = 81619 n = 6704 n = 12342 n = 31861 Mean (SD) 2383.46 (1486.15) 802.02 (1136.05) < 0.001 2364.5 (1443.6) 1549.73 (1237.62) 603.863 (920.229) < 0.001 Median (Q1, Q3) 2194.21 (1391.13, 3111.86) 165.88 (20.89, 1379.33) < 0.001 2148.73 (1394.18, 3062.56) 1424.98 (539.197, 2284.96) 102.252 (20.296, 907.837) < 0.001 Laboratory examination n = 2753 n = 31183 n = 2725 n = 4661 n = 13874 Mean (SD) 1993.57 (2140.99) 795.13 (954.91) < 0.001 2149.44 (2194.9) 1399.11 (1293.78) 790.735 (770.567) < 0.001 Median (Q1, Q3) 1546.78 (45.89, 3154.54) 573.86 (114.31, 1056.16) < 0.001 1739.9 (78.57, 3365.92) 1230.3 (126.302, 2034.53) 665.97 (332.264, 1029.61) < 0.001 Radiologic examination n = 7293 n = 75048 n = 6682 n = 12296 n = 30386 Mean (SD) 867.79 (959.00) 387.19 (524.15) < 0.001 943.127 (994.827) 622.531 (687.427) 382.796 (461.548) < 0.001 Median (Q1, Q3) 485.98 (258.88, 1136.19) 195.83 (62.48, 522.15) < 0.001 540.165 (283.88, 1322.55) 340.18 (138.38, 912.965) 231.7 (65.39, 563.11) < 0.001 Functional examination n = 7271 n = 76910 n = 6669 n = 12288 n = 30753 Mean (SD) 267.79 (193.65) 156.09 (132.15) < 0.001 271.344 (185.444) 249.259 (147.188) 149.377 (114.514) < 0.001 Median (Q1, Q3) 223.6 (147.84, 349.32) 128.52 (67.08, 209.88) < 0.001 229.84 (158.78, 351.2) 226.8 (163.595, 315.175) 128.57 (78.26, 192.78) < 0.001 Trend in healthcare costs of preterm singletons Figure 2 illustrates the annual trends in healthcare-related costs from the hospitalization of preterm neonates between 2008 and 2020. Overall, the total medical cost per patient almost tripled in all preterm newborns ( $ 7,390.90 to $ 20,209.59), but that of extremely preterm < 28 weeks increased fourfold ( $ 13,961.03 to $ 55,984.47), Fig. 2 A, Supplementary Table 1A). The medication cost was constant for all preterm births over time; however, it increased in case of the extremely preterm group (Fig. 2 B, Supplementary Table 1B). In contrast, laboratory examination costs were minimal until 2017, after which they increased significantly, especially in the extremely preterm group (Fig. 2 C, Supplementary Table 1C). Expenses due to radiological examinations showed a similar trend, increasing after 2016 (Fig. 2 D, Supplementary Table 1D). Finally, the cost of functional examination showed a steady increase over time, with a more prominent slope for the extremely preterm group (Fig. 2 E, Supplementary Table 1E). Readmission rate in preterm singleton neonates Among 90,575 preterm births, 56,600 (62.5%) were readmitted within 90 days of the initial discharge (Table 3 ). The readmission rates were relatively similar between the extreme and non-extreme preterm groups (65.9% vs. 62.2%). However, the proportion of the extremely preterm group readmitted within 30 days of discharge was twice that of the non-extremely preterm group (16.1% vs. 8.32%; P < 0.001). The odds of readmission within 30 days of extremely preterm group were more than twice as non-extremely preterm group. Regarding the expenses due to rehospitalization, the total cost was approximately 1.5 times greater in the extremely preterm group (mean $ 4293.8 vs. $ 2975.4, P < 0.001). Table 3 Readmission rates and medical burden of preterm singletons by gestational age < 28wks 28wks to < 37wks OR (95% CI) p value Total readmission rate, N(%) n = 4867 n = 51733 Readmission rate within 30 days of discharge, N (%) 1191 (16.14) 6925 (8.32) 2.119 (1.983, 2.266) < 0.001 Readmission rate within 60 days of discharge, N (%) 1796 (24.34) 11926 (14.33) 1.922 (1.816, 2.034) < 0.001 Readmission rate within 90 days of discharge, N (%) 2172 (29.43) 15101 (18.15) 1.881 (1.783, 1.983) < 0.001 Total direct medical cost per patient for readmission within 90 days of discharge, USD beta (95% CI) mean (SD) 4293.77 (8484.56) 2975.36 (8443.11) 1318.406 (938.391, 1698.420) < 0.001 median (Q1, Q3) 1738.54 (829.76,3822.16) 1097.38 (567.58, 2410.03) < 0.001 DISCUSSION The preterm birth rate has increased, whereas the total number of live births in South Korea has decreased. The total number of preterm infants has increased slightly. Preterm births under 28 weeks of GA increased until 2015, to 752 infants, and declined after 2015. Earlier GA was strongly associated with increased healthcare resource utilization and medical costs in Korea, especially in the extremely preterm group. 10 The total medical costs of preterm infants steadily increased throughout the study period. In 2008, the Korean Ministry of Health and Welfare established “The Service for National Support of NICU Installation and Management.” An agreement for raising the admission fee for the NICU was signed in 2013, which included a zero-deductible payment for the patient and the entire admission fee for patients requiring incubators. This development solved chronic deficits for hospitals running the NICU and contributed significantly to the healthcare of preterm infants by lowering neonatal mortality. 11 , 12 In the 2016 policy revision (The 14th National Healthcare Insurance Policy Board Congress), guaranteed admission fees were increased again and provided an expanded non-benefit practice. Additionally, the costs of diagnostic tests and treatments have changed over time. However, the cost of medication has remained constant over time, including that of pulmonary surfactants and respiratory syncytial virus monoclonal antibodies (Synagis®, palivizumab), which are covered by national insurance since 2010. 11 , 13 , 14 In 2018, more diverse surfactant agents were included in the national health coverage (other than Curosurf). Laboratory diagnostic costs have increased steeply since 2017. A new laboratory methodology called next-generation sequencing was included in the national insurance coverage for newborn congenital diseases from March 2017. 15 Also, respiratory viral panel by polymerase chain reaction study has been included in the coverage since 2016. The expansion of laboratory studies performed in NICU has led to a dramatic increase in the costs in the laboratory category. Ultrasonography is a useful imaging modality for neonates. Sonographic examinations have been covered by national insurance since 2016 and are routinely performed through discretionary grant payments from each patient. This coverage contributed to a steep increase in radiological costs from 2016. Other functional examinations, including electroencephalography, echocardiography, or video fluoroscopic swallowing studies, remained steady because fees were not raised during the study period. Several previous works about economic burden with preterm birth have been investigated. Canada runs national health insurance model which is comparable with South Korea. Johnston et al., estimated in his paper that it costed $ CAD 67,467 for each early preterm infant (less than 28 gestational weeks), $ CAD 54,554 for moderately preterm (28 to 32 gestational weeks) and $ CAD 10,010 for late preterm (32 to 36 gestational weeks) in year 2012. 16 Rolnistsky et al., published 2 papers related to expenses of the NICU care in Canada. In these studies, extremely preterm infants (less than 28 gestational weeks) accounted $ CAD 66,669 in 2011 through 2015 and in year 2010 through 2017, and total median cost per all NICU infant was $ CAD 77,132. 17 , 18 Healthcare spendings in U.S. was even larger than national covered nations. Beam et al., reported median $ 291,029 expenditure was spent for each preterm infant born with 27 to 28 gestational weeks of age, $ 418,191 for 25 to 26 gestational weeks and $ 9,864 for 35 to 36 gestational weeks in year 2008 to 2016. 19 Beam et al., also suggested that total cost has been rising through recent years as well. Comparing with our data, it costed $ 29,101 for extremely preterm infant which is less than Northern American nations. But it is also noticeable that in non-extreme preterm, expense was $ 9,181 per infant, which was similar amount compared to previous studies from other nations. As total burden of preterm medical cost increases, we need more wisdom to invest strategies to address more portion to target earlier born infants. Jin et al., studied first 6 years medical costs in preterm infants after discharge from NICU in Korea. 10 Rate of hospital admission was 75.6% in infants born less than 28 gestational weeks in 6 years and most of the costs was spent in the first year after discharge. In our data, we focused more on advanced period and re-admission happened 16% in 30 days, 24% in 60 days and 29% in 90 days after discharge in extremely preterm infants. This study has multiple strength including large population size, distribution of birth location and categorized expenditure by different purpose of medical utilization. Several limitations should be acknowledged. Korean national insurance coverage is not 100% and there could be missing expenditure from uninsured portion from arbitrary out-of-pocket expenses. Second limitation is from weakness of the large claim data. We utilized ICD-10 codes to search preterm admission bills, but codes may not be perfect as incomplete data input may occur from different units. Third limitation is also brought from large scale of national data which does not include detail patient individual data such as accurate gestational age other than 28 weeks cut-offs and specific birth weight information. Conclusion Preterm births have increased, whereas the total live births in Korea have been declining to a worrisome level. In recent decades, medical costs and national insurance coverage for preterm infants have increased. Further attention should be paid to improving preterm healthcare and alleviating the medical burden of preterm births at a national level. Declarations Author contributions Conceptualization: All authors. Data Curation: ML and MH. Formal analysis: ML, MH, and IJ. Funding acquisition: JGA. Investigation: All authors. Methodology: ML, MH, IJ, JGA, and MSP. Software: ML, MH. Validation: JP, JGA, JYL, IJ, and MSP. Visualization: ML. Writing the original draft: JP and JYL. Writing, review, and editing: JP, JYL, and ML. Acknowledgements We used data from the National Health Information Database (M20210702352) of the Health Insurance Review and Assessment Services. Disclosures This study was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (No. 2022R1G1A100844111) and the faculty research grant of Yonsei University College of Medicine (6-2021-0145). The study sponsor was not involved in the study design, analysis and interpretation of data, writing of the report, or the decision to submit the study results for publication. References Boardman, J. P. Preterm Birth: Causes, Consequences and Prevention. Journal of Obstetrics and Gynaecology 28 , 559-559 (2009). Russell, R. B. et al. Cost of hospitalization for preterm and low birth weight infants in the United States. Pediatrics 120 , e1-9 (2007). Martin, J. A. et al. Births: final data for 2003. Natl Vital Stat Rep 54 , 1-116 (2005). Goldenberg, R. L., Culhane, J. F., Iams, J. D. & Romero, R. Epidemiology and causes of preterm birth. The Lancet 371 , 75-84 (2008). Mortality, G. B. D. & Causes of Death, C. Global, regional, and national life expectancy, all-cause mortality, and cause-specific mortality for 249 causes of death, 1980-2015: a systematic analysis for the Global Burden of Disease Study 2015. Lancet 388 , 1459-1544 (2016). Chawanpaiboon, S. et al. Global, regional, and national estimates of levels of preterm birth in 2014: a systematic review and modelling analysis. The Lancet Global Health 7 , e37-e46 (2019). Juan, J. et al. Effect of coronavirus disease 2019 (COVID-19) on maternal, perinatal and neonatal outcome: systematic review. Ultrasound Obstet Gynecol 56 , 15-27 (2020). Hedermann, G. et al. Danish premature birth rates during the COVID-19 lockdown. Arch Dis Child Fetal Neonatal Ed 106 , 93-95 (2021). Hwang, J. et al. Changes in preterm birth and birthweight during the SARS-CoV-2 pandemic: a nationwide study in South Korea. Sci Rep 12 , 16288 (2022). Jin, J. H., Lee, S. A. & Yoon, S. W. Medical Utilization and Costs in Preterm Infants in the First 6 Years of Life After Discharge From Neonatal Intensive Care Unit: A Nationwide Population-Based Study in Korea. J Korean Med Sci 37 , e93 (2022). Bae, C.-W. The history of neonatology in Korea. Journal of the Korean Medical Association 59 (2016). Shim, J. W., Jin, H. S. & Bae, C. W. Changes in Survival Rate for Very-Low-Birth-Weight Infants in Korea: Comparison with Other Countries. J Korean Med Sci 30 Suppl 1 , S25-34 (2015). Singh, D., Rana, K. S. & Mathai, S. Role of prophylactic surfactant in preterm infants. Med J Armed Forces India 67 , 138-141 (2011). Park, S. K. et al. Effect of Synagis® (palivizumab) prophylaxis on readmission due to respiratory syncytial virus in very low birth weight infants. Korean Journal of Pediatrics 53 (2010). OECD. Health at a Glance 2017 2017). Johnston, K. M. et al. The economic burden of prematurity in Canada. BMC Pediatr 14 , 93 (2014). Rolnitsky, A., Unger, S., Urbach, D. & Bell, C. M. The price of neonatal intensive care outcomes - in-hospital costs of morbidities related to preterm birth. Front Pediatr 11 , 1068367 (2023). Rolnitsky, A., Unger, S. L., Urbach, D. R. & Bell, C. M. Cost of neonatal intensive care for extremely preterm infants in Canada. Transl Pediatr 10 , 1630-1636 (2021). Beam, A. L. et al. Estimates of healthcare spending for preterm and low-birthweight infants in a commercially insured population: 2008-2016. J Perinatol 40 , 1091-1099 (2020). Supplementary Table Supplementary Table 1 are not available with this version. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 24 Apr, 2025 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 30 Apr, 2024 Reviews received at journal 30 Apr, 2024 Reviewers agreed at journal 26 Apr, 2024 Reviews received at journal 22 Dec, 2023 Reviewers agreed at journal 05 Dec, 2023 Reviewers invited by journal 16 Nov, 2023 Editor assigned by journal 25 Oct, 2023 Editor invited by journal 22 Sep, 2023 Submission checks completed at journal 22 Sep, 2023 First submitted to journal 12 Sep, 2023 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. 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Korea.","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Minkyung","middleName":"","lastName":"Han","suffix":""},{"id":235464550,"identity":"0f56d85d-0f49-4b6b-9256-9b002a177288","order_by":4,"name":"Sung Min Lim","email":"","orcid":"","institution":"Department of Pediatrics, Severance Children’s Hospital, Yonsei University College of Medicine, Seoul, Korea.","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Sung","middleName":"Min","lastName":"Lim","suffix":""},{"id":235464551,"identity":"e5eb93e1-7e67-4fa9-b378-a0d4b35b8757","order_by":5,"name":"Jee Yeon Baek","email":"","orcid":"","institution":"Department of Pediatrics, Severance Children’s Hospital, Yonsei University College of Medicine, Seoul, Korea.","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Jee","middleName":"Yeon","lastName":"Baek","suffix":""},{"id":235464552,"identity":"e5d5f6b3-fd33-444b-a327-463a8550e3f9","order_by":6,"name":"Ji-Man Kang","email":"","orcid":"","institution":"Department of Pediatrics, Severance Children’s Hospital, Yonsei University College of Medicine, Seoul, Korea.","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Ji-Man","middleName":"","lastName":"Kang","suffix":""},{"id":235464553,"identity":"5d07042c-a0fa-4125-87c1-31d10a1e7f1b","order_by":7,"name":"Min Soo Park","email":"","orcid":"","institution":"Department of Pediatrics, Severance Children’s Hospital, Yonsei University College of Medicine, Seoul, Korea.","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Min","middleName":"Soo","lastName":"Park","suffix":""},{"id":235464554,"identity":"63e1de32-0f1a-4b06-b717-909427a17b06","order_by":8,"name":"Inkyung Jung","email":"","orcid":"","institution":"Division of Biostatistics, Department of Biomedical Systems Informatics, Yonsei University College of Medicine, Seoul, Korea.","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Inkyung","middleName":"","lastName":"Jung","suffix":""},{"id":235464555,"identity":"7e9134ae-b585-4f50-910e-c03291834b1c","order_by":9,"name":"Jong Gyun Ahn","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAr0lEQVRIiWNgGAWjYBAC9vaDbdI8FQwMBkRrYexJPibdc4YkLTPY0qTPtpGmhcdM+uy8w4nb+Q8wfvhBpBbz37nbDifunJHALNlDnJY3ZtIgLRtuMDBIE+mw/G/StnOAWs4fYP5NlBbBGTlm0rINQC0HEtiIs0WaB6hF5li68YYbiW2WRPmFj/2MmTRPjbXshvOHD98gKsSgoBmIGRtI0MDAUEeS6lEwCkbBKBhhAAC49DY0vspH6QAAAABJRU5ErkJggg==","orcid":"","institution":"Department of Pediatrics, Severance Children’s Hospital, Yonsei University College of Medicine, Seoul, Korea.","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Jong","middleName":"Gyun","lastName":"Ahn","suffix":""}],"badges":[],"createdAt":"2023-09-12 17:14:10","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3349473/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3349473/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41598-025-98868-2","type":"published","date":"2025-04-24T15:56:55+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":43893902,"identity":"ef9fc58a-6774-475a-b517-e68e6ac26250","added_by":"auto","created_at":"2023-09-29 17:54:07","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":122209,"visible":true,"origin":"","legend":"\u003cp\u003eFlow chart of the study population\u003c/p\u003e","description":"","filename":"figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-3349473/v1/cde92e809df6aa31c49cb769.png"},{"id":43893903,"identity":"5eef7e74-b323-42ea-8a78-f666582ed58b","added_by":"auto","created_at":"2023-09-29 17:54:07","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":182209,"visible":true,"origin":"","legend":"\u003cp\u003eTrends in healthcare costs of preterm singletons by year, 2008-2021\u003c/p\u003e\n\u003cp\u003e(A) Total medical cost ($) (B) Medication cost ($), (C) laboratory diagnostic test cost ($) (D) Radiological/imaging exam cost ($), (E) functional examination cost ($)\u003c/p\u003e","description":"","filename":"figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-3349473/v1/ddd389ca7e8874045de545af.png"},{"id":81569522,"identity":"2998eff5-32b6-4fc4-abbd-6590e7010179","added_by":"auto","created_at":"2025-04-28 16:04:55","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1295329,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3349473/v1/3d12d414-6d35-4745-aac3-4667842acd25.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003e\u003cstrong\u003eRising Public Cost of Preterm Infant Hospitalization: A nationwide observational study in South Korea\u003c/strong\u003e\u003c/p\u003e","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eNeonatal diseases account for the largest share of pediatric hospital stays and costs in the United States.\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e Of these, premature birth is still the leading cause of neonatal mortality and morbidities in developed countries.\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e The rate of preterm birth in the United States increased steadily to 12.3% in 2004.\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e,\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e The global burden of disease reported that neonatal disorders, still one of the leading causes of death among children under five years, accounted for 2.1\u0026ndash;2.2\u0026nbsp;million deaths in 2015.\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eSome worldwide cohort studies reported that the increasing trend of preterm birth has been mitigated.\u003csup\u003e\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e However, our study group reported, in a previous study, that even during COVID-19 pandemics, the preterm birth rate in South Korea increased consistently, until recently.\u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eAdditionally, hospital fees per single preterm infant have also increased, according to annual reports from the United States.\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e Korean data have not been investigated; however, we can assume that trends in neonatal practice in Korea have moved commensurately with technical advancement. National health insurance coverage should be considered as one of the factors for total expenditure on hospitalization, as financial accessibility has increased the availability of medical practice and examinations.\u003c/p\u003e \u003cp\u003eThe objective of this study is to estimate the preterm infant hospitalization costs covered by national public insurance in South Korea, and to compare the yearly changes from the data and indicated annual events, such as changes in the government\u0026rsquo;s insurance coverage policies.\u003c/p\u003e"},{"header":"METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eData Source\u003c/h2\u003e \u003cp\u003eWe used population-based data from the National Health Insurance Service (NHIS), operated by the Health Insurance Review and Assessment Service, a universal health reimbursement insurer that covers 98% of the Korean population. The database includes information on not only the clinical characteristics of the cohort, but also the prescribed diagnostic tests and treatments covered by the NHIS. The information from the first inpatient claims data, registered with diagnostic codes related to preterm births, was used.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eStudy design\u003c/h2\u003e \u003cp\u003eThis is a retrospective cohort study to assess the trends in healthcare utilization and medical costs associated with preterm births, covered by the NHIS from January 1, 2007, to February 28, 2021. Neonates, who were registered with diagnostic codes related to prematurity in 2007, were excluded as a washout period owing to possible delays in receipt registration. Additionally, because the 2021 data included information for only two months, we excluded that year from the study as well. Further, multiple claims data from the same patient were excluded to include only the claims data for the first prematurity-related hospitalization.\u003c/p\u003e \u003cp\u003eThe outcomes on length of hospitalization and medical costs using operational definitions, such as medication and laboratory, radiological, and functional examinations, were analyzed using gestational age (GA) and birth weight.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eStudy population\u003c/h2\u003e \u003cp\u003eWe included those with prematurity-related codes of \u003cem\u003eInternational Classification of Diseases and Related Health Problems\u003c/em\u003e, 10th edition (ICD-10), and included multiple births. As extreme preterm birth or birth at \u0026lt;\u0026thinsp;28 weeks of GA is associated with higher mortality and morbidity, we categorized prematurity into extremely preterm (P07.2 on ICD-10) and non-extremely preterm (P07.3 on ICD-10).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eWe divided preterm infants into extreme (less than 28 gestational weeks) and non-extreme (gestational weeks between 28 and 37) preterm birth groups. Thereafter, we compared these two groups according to baseline characteristics, length of hospitalization, medical costs, and proportion of re-hospitalization. Categorical variables were expressed as frequencies and percentages (%) and were compared using the chi-square test. Continuous variables were expressed as mean and standard deviation (SD) or medians (first quartile(Q1), third quartile(Q3)), and compared using the independent t-test or Wilcoxon rank-sum test, respectively. Statistical significance was defined as a two-sided \u003cem\u003eP-\u003c/em\u003evalue of \u0026lt;\u0026thinsp;0.05. Statistical analyses were performed using the SAS Enterprise Guide version 7.1 (SAS Institute Inc., Cary, NC, USA).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eEthics statement\u003c/h2\u003e \u003cp\u003eThis study was conducted in accordance with the World Medical Association and the Declaration of Helsinki, and the Institutional Review Board (IRB) of Severance Hospital, Yonsei University, Seoul, Republic of Korea (No. 4-2021-0416) approved the study. The IRB has waived the requirement for informed consent due to the minimal-risk nature of the research.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eData availability\u003c/h2\u003e \u003cp\u003eThe data that support the findings of this study are available from National Health Insurance Service (NHIS), operated by the Health Insurance Review and Assessment Service of Government of Republic of Korea. But restrictions apply to the availability of these data, which were used under license for the current study, and so are not publicly available. Data are however available from the authors upon reasonable request and with permission of NHIS.\u003c/p\u003e \u003c/div\u003e"},{"header":"RESULTS","content":"\u003cp\u003eFrom 2008 to 2020, a total of 5,312,886 live birth infants gave birth in total nation. Among which 137,214 infants were claimed as diagnosis of premature born infant. We excluded 46,639 infants who were only claimed as outpatient clinics and have not been hospitalized (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). A slight male predominance was observed in preterm neonates (54.0%, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The number of preterm births more than doubled from 3,722 (4%) in 2008 to 9,009 (9.9%) in 2020 (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001), with a similar frequency across the seasons. About 99% of the preterm births, were covered by the NHIS, and 47% of preterm birth deliveries were observed in the main urban areas in Korea, such as Seoul and the suburban Gyeonggi province. Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e shows the characteristics of preterm births.\u003c/p\u003e \u003cp\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\u003eBaseline characteristics of preterm births by gestational age\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\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 \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003eExtremely Preterm Infants (less than 28 weeks)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003eNon-extreme Preterm Infants (28 to 37 gestational weeks)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e%\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003en\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e%\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003ep value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eN (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e90575\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e7380\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e83195\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSex N (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e48928\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3831\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e51.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e45097\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e54.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e41647\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3549\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e48.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e38098\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e45.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eBirth year, N (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2008\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3733\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e312\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e3421\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e4.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2009\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4128\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e317\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e3811\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e4.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2010\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4779\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e318\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e4461\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e5.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2011\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5291\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e591\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e8.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e4700\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e5.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2012\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5952\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e697\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e9.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e5255\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e6.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2013\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6761\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e660\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e8.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e6101\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e7.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2014\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e7344\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e713\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e9.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e6631\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e8.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2015\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e7928\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e752\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e10.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e7176\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e8.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2016\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e8252\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e678\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e9.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e7574\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e9.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2017\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9090\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e589\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e8.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e8501\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e10.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2018\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9134\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e589\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e8.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e8545\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e10.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2019\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9174\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e587\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e8.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e8587\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e10.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2020\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9009\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e577\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e7.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e8432\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e10.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSeason, N (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWinter (Dec-Feb)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e22778\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1831\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e24.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20947\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e25.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.6122\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSpring (Mar-May)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e22075\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1769\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e24.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20306\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e24.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSummer (Jun-Aug)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e22996\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1895\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e25.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e21101\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e25.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAutumn (Sep-Nov)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e22726\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1885\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e25.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20841\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e25.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDelivery payment source, N (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNHIS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e89706\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e7326\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e99.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e82380\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e99.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0363\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedical aid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e869\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e815\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDelivery location, N (%) #\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSeoul, Gyeonggi-do\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e42562\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3606\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e49.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e38956\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e47.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMetropolitan cities\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e29905\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2599\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e35.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e27306\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e33.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOther (rural area)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e16932\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1136\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e15.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e15796\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e19.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003eMedical burden of preterm singleton birth hospitalization\u003c/h2\u003e \u003cp\u003eWe analyzed the medical costs associated with hospitalization for preterm births at 28 weeks GA and birth weight. The median length of hospitalization for extremely preterm singleton neonates was almost twice that for preterm infants older than 28 weeks GA (40 days, IQR 28\u0026ndash;60 vs. 21 days, IQR 11\u0026ndash;35, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The mean medical cost per patient was higher for the extremely preterm group than for those born before 28 weeks (\u003cspan\u003e$\u003c/span\u003e33,872.2, SD \u003cspan\u003e$\u003c/span\u003e24,369.2 vs. \u003cspan\u003e$\u003c/span\u003e12,713, SD \u003cspan\u003e$\u003c/span\u003e13,078.8). When the cost was categorized according to medication and type of diagnostic examination, the former accounted for the majority of the cost in both, extremely preterm and other preterm neonates (\u003cspan\u003e$\u003c/span\u003e2383.5, SD \u003cspan\u003e$\u003c/span\u003e1486.2 vs. \u003cspan\u003e$\u003c/span\u003e802.0, SD \u003cspan\u003e$\u003c/span\u003e1136.1), but at a slightly higher proportion in the extremely preterm group (43.2% vs. 37.4%, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Moreover, the cost of laboratory examinations was the major source of expenses for diagnostic tests, such as radiological and functional examinations, in both the GA groups (63.7% vs. 59.4%, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\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\u003eMedical burden of birth hospitalization for preterm singletons by gestational age, 2008\u0026ndash;2020\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eExtremely Preterm Infants\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNon-extreme Preterm Infants\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003ebw\u0026thinsp;\u0026lt;\u0026thinsp;1000g\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1000g\u0026thinsp;\u0026le;\u0026thinsp;bw\u0026thinsp;\u0026lt;\u0026thinsp;1500g\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1500g\u0026thinsp;\u0026le;\u0026thinsp;bw\u0026thinsp;\u0026lt;\u0026thinsp;2500g\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003ep value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAverage length of hospitalization, days\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedian (Q1, Q3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e40 (28, 60)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21 (11,35)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e40 (29, 59)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e40 (30, 53)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e20 (13, 30)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal direct medical cost, USD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMean (SD)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33872.23 (24369.23)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12713.66 (13078.77)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e35805.78 (23967.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e24900.19 (15555.44)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e12098.89 (10418.92)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedian (Q1, Q3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e29101.33 (16460.45, 45543.52)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9181.53 (3590.14, 17554.82)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e31194.74 (18722.12, 47137.71)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e22025.08 (13993.52, 32670.32)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e9807.06 (5092.76, 16384.92)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eComparison of components of direct medical costs per patient, USD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003eMedication\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;7348\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;81619\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;6704\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;12342\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;31861\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMean (SD)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2383.46 (1486.15)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e802.02 (1136.05)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2364.5 (1443.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1549.73 (1237.62)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e603.863 (920.229)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedian (Q1, Q3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2194.21 (1391.13, 3111.86)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e165.88 (20.89, 1379.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2148.73 (1394.18, 3062.56)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1424.98 (539.197, 2284.96)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e102.252 (20.296, 907.837)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003eLaboratory examination\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;2753\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;31183\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;2725\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;4661\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;13874\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMean (SD)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1993.57 (2140.99)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e795.13 (954.91)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2149.44 (2194.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1399.11 (1293.78)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e790.735 (770.567)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedian (Q1, Q3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1546.78 (45.89, 3154.54)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e573.86 (114.31, 1056.16)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1739.9 (78.57, 3365.92)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1230.3 (126.302, 2034.53)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e665.97 (332.264, 1029.61)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003eRadiologic examination\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;7293\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;75048\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;6682\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;12296\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;30386\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMean (SD)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e867.79 (959.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e387.19 (524.15)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e943.127 (994.827)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e622.531 (687.427)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e382.796 (461.548)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedian (Q1, Q3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e485.98 (258.88, 1136.19)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e195.83 (62.48, 522.15)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e540.165 (283.88, 1322.55)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e340.18 (138.38, 912.965)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e231.7 (65.39, 563.11)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003eFunctional examination\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;7271\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;76910\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;6669\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;12288\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;30753\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMean (SD)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e267.79 (193.65)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e156.09 (132.15)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e271.344 (185.444)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e249.259 (147.188)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e149.377 (114.514)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedian (Q1, Q3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e223.6 (147.84, 349.32)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e128.52 (67.08, 209.88)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e229.84 (158.78, 351.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e226.8 (163.595, 315.175)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e128.57 (78.26, 192.78)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eTrend in healthcare costs of preterm singletons\u003c/h2\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e illustrates the annual trends in healthcare-related costs from the hospitalization of preterm neonates between 2008 and 2020. Overall, the total medical cost per patient almost tripled in all preterm newborns (\u003cspan\u003e$\u003c/span\u003e7,390.90 to \u003cspan\u003e$\u003c/span\u003e20,209.59), but that of extremely preterm\u0026thinsp;\u0026lt;\u0026thinsp;28 weeks increased fourfold (\u003cspan\u003e$\u003c/span\u003e13,961.03 to \u003cspan\u003e$\u003c/span\u003e55,984.47), Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eA, Supplementary Table\u0026nbsp;1A). The medication cost was constant for all preterm births over time; however, it increased in case of the extremely preterm group (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eB, Supplementary Table\u0026nbsp;1B). In contrast, laboratory examination costs were minimal until 2017, after which they increased significantly, especially in the extremely preterm group (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eC, Supplementary Table\u0026nbsp;1C). Expenses due to radiological examinations showed a similar trend, increasing after 2016 (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eD, Supplementary Table\u0026nbsp;1D). Finally, the cost of functional examination showed a steady increase over time, with a more prominent slope for the extremely preterm group (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eE, Supplementary Table\u0026nbsp;1E).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eReadmission rate in preterm singleton neonates\u003c/h2\u003e \u003cp\u003eAmong 90,575 preterm births, 56,600 (62.5%) were readmitted within 90 days of the initial discharge (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The readmission rates were relatively similar between the extreme and non-extreme preterm groups (65.9% vs. 62.2%). However, the proportion of the extremely preterm group readmitted within 30 days of discharge was twice that of the non-extremely preterm group (16.1% vs. 8.32%; \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001). The odds of readmission within 30 days of extremely preterm group were more than twice as non-extremely preterm group. Regarding the expenses due to rehospitalization, the total cost was approximately 1.5 times greater in the extremely preterm group (mean \u003cspan\u003e$\u003c/span\u003e4293.8 vs. \u003cspan\u003e$\u003c/span\u003e2975.4, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\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\u003eReadmission rates and medical burden of preterm singletons by gestational age\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;28wks\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e28wks to \u0026lt;\u0026thinsp;37wks\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eOR (95% CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003ep value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal readmission rate, N(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;4867\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u0026thinsp;=\u0026thinsp;51733\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eReadmission rate within 30 days of discharge, N (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1191 (16.14)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6925 (8.32)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.119 (1.983, 2.266)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eReadmission rate within 60 days of discharge, N (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1796 (24.34)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11926 (14.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.922 (1.816, 2.034)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eReadmission rate within 90 days of discharge, N (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2172 (29.43)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15101 (18.15)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.881 (1.783, 1.983)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTotal direct medical cost per patient for readmission within 90 days of discharge, USD\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ebeta (95% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003emean (SD)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4293.77 (8484.56)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2975.36 (8443.11)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1318.406 (938.391, 1698.420)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003emedian (Q1, Q3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1738.54 (829.76,3822.16)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1097.38 (567.58, 2410.03)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eThe preterm birth rate has increased, whereas the total number of live births in South Korea has decreased. The total number of preterm infants has increased slightly. Preterm births under 28 weeks of GA increased until 2015, to 752 infants, and declined after 2015. Earlier GA was strongly associated with increased healthcare resource utilization and medical costs in Korea, especially in the extremely preterm group.\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eThe total medical costs of preterm infants steadily increased throughout the study period. In 2008, the Korean Ministry of Health and Welfare established \u0026ldquo;The Service for National Support of NICU Installation and Management.\u0026rdquo; An agreement for raising the admission fee for the NICU was signed in 2013, which included a zero-deductible payment for the patient and the entire admission fee for patients requiring incubators. This development solved chronic deficits for hospitals running the NICU and contributed significantly to the healthcare of preterm infants by lowering neonatal mortality.\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e,\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e In the 2016 policy revision (The 14th National Healthcare Insurance Policy Board Congress), guaranteed admission fees were increased again and provided an expanded non-benefit practice.\u003c/p\u003e \u003cp\u003eAdditionally, the costs of diagnostic tests and treatments have changed over time. However, the cost of medication has remained constant over time, including that of pulmonary surfactants and respiratory syncytial virus monoclonal antibodies (Synagis\u0026reg;, palivizumab), which are covered by national insurance since 2010.\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e,\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e,\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e In 2018, more diverse surfactant agents were included in the national health coverage (other than Curosurf). Laboratory diagnostic costs have increased steeply since 2017. A new laboratory methodology called next-generation sequencing was included in the national insurance coverage for newborn congenital diseases from March 2017.\u003csup\u003e\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u003c/sup\u003e Also, respiratory viral panel by polymerase chain reaction study has been included in the coverage since 2016. The expansion of laboratory studies performed in NICU has led to a dramatic increase in the costs in the laboratory category.\u003c/p\u003e \u003cp\u003eUltrasonography is a useful imaging modality for neonates. Sonographic examinations have been covered by national insurance since 2016 and are routinely performed through discretionary grant payments from each patient. This coverage contributed to a steep increase in radiological costs from 2016. Other functional examinations, including electroencephalography, echocardiography, or video fluoroscopic swallowing studies, remained steady because fees were not raised during the study period.\u003c/p\u003e \u003cp\u003eSeveral previous works about economic burden with preterm birth have been investigated. Canada runs national health insurance model which is comparable with South Korea. Johnston et al., estimated in his paper that it costed \u003cspan\u003e$\u003c/span\u003eCAD 67,467 for each early preterm infant (less than 28 gestational weeks), \u003cspan\u003e$\u003c/span\u003eCAD 54,554 for moderately preterm (28 to 32 gestational weeks) and \u003cspan\u003e$\u003c/span\u003eCAD 10,010 for late preterm (32 to 36 gestational weeks) in year 2012.\u003csup\u003e \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e \u003c/sup\u003e Rolnistsky et al., published 2 papers related to expenses of the NICU care in Canada. In these studies, extremely preterm infants (less than 28 gestational weeks) accounted \u003cspan\u003e$\u003c/span\u003eCAD 66,669 in 2011 through 2015 and in year 2010 through 2017, and total median cost per all NICU infant was \u003cspan\u003e$\u003c/span\u003eCAD 77,132.\u003csup\u003e \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e,\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e \u003c/sup\u003e Healthcare spendings in U.S. was even larger than national covered nations. Beam et al., reported median \u003cspan\u003e$\u003c/span\u003e291,029 expenditure was spent for each preterm infant born with 27 to 28 gestational weeks of age, \u003cspan\u003e$\u003c/span\u003e418,191 for 25 to 26 gestational weeks and \u003cspan\u003e$\u003c/span\u003e9,864 for 35 to 36 gestational weeks in year 2008 to 2016.\u003csup\u003e \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e \u003c/sup\u003e Beam et al., also suggested that total cost has been rising through recent years as well.\u003c/p\u003e \u003cp\u003eComparing with our data, it costed \u003cspan\u003e$\u003c/span\u003e29,101 for extremely preterm infant which is less than Northern American nations. But it is also noticeable that in non-extreme preterm, expense was \u003cspan\u003e$\u003c/span\u003e9,181 per infant, which was similar amount compared to previous studies from other nations. As total burden of preterm medical cost increases, we need more wisdom to invest strategies to address more portion to target earlier born infants.\u003c/p\u003e \u003cp\u003eJin et al., studied first 6 years medical costs in preterm infants after discharge from NICU in Korea.\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e Rate of hospital admission was 75.6% in infants born less than 28 gestational weeks in 6 years and most of the costs was spent in the first year after discharge. In our data, we focused more on advanced period and re-admission happened 16% in 30 days, 24% in 60 days and 29% in 90 days after discharge in extremely preterm infants.\u003c/p\u003e \u003cp\u003eThis study has multiple strength including large population size, distribution of birth location and categorized expenditure by different purpose of medical utilization. Several limitations should be acknowledged. Korean national insurance coverage is not 100% and there could be missing expenditure from uninsured portion from arbitrary out-of-pocket expenses. Second limitation is from weakness of the large claim data. We utilized ICD-10 codes to search preterm admission bills, but codes may not be perfect as incomplete data input may occur from different units. Third limitation is also brought from large scale of national data which does not include detail patient individual data such as accurate gestational age other than 28 weeks cut-offs and specific birth weight information.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003ePreterm births have increased, whereas the total live births in Korea have been declining to a worrisome level. In recent decades, medical costs and national insurance coverage for preterm infants have increased. Further attention should be paid to improving preterm healthcare and alleviating the medical burden of preterm births at a national level.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor contributions\u003c/h2\u003e \u003cp\u003eConceptualization: All authors. Data Curation: ML and MH. Formal analysis: ML, MH, and IJ. Funding acquisition: JGA. Investigation: All authors. Methodology: ML, MH, IJ, JGA, and MSP. Software: ML, MH. Validation: JP, JGA, JYL, IJ, and MSP. Visualization: ML. Writing the original draft: JP and JYL. Writing, review, and editing: JP, JYL, and ML.\u003c/p\u003e\u003ch2\u003eAcknowledgements\u003c/h2\u003e \u003cp\u003eWe used data from the National Health Information Database (M20210702352) of the Health Insurance Review and Assessment Services.\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eDisclosures\u003c/strong\u003e \u003cp\u003eThis study was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (No. 2022R1G1A100844111) and the faculty research grant of Yonsei University College of Medicine (6-2021-0145). The study sponsor was not involved in the study design, analysis and interpretation of data, writing of the report, or the decision to submit the study results for publication.\u003c/p\u003e \u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eBoardman, J. P. Preterm Birth: Causes, Consequences and Prevention. \u003cem\u003eJournal of Obstetrics and Gynaecology\u003c/em\u003e \u003cstrong\u003e28\u003c/strong\u003e, 559-559 (2009).\u003c/li\u003e\n\u003cli\u003eRussell, R. B.\u003cem\u003e et al.\u003c/em\u003e Cost of hospitalization for preterm and low birth weight infants in the United States. \u003cem\u003ePediatrics\u003c/em\u003e \u003cstrong\u003e120\u003c/strong\u003e, e1-9 (2007).\u003c/li\u003e\n\u003cli\u003eMartin, J. A.\u003cem\u003e et al.\u003c/em\u003e Births: final data for 2003. \u003cem\u003eNatl Vital Stat Rep\u003c/em\u003e \u003cstrong\u003e54\u003c/strong\u003e, 1-116 (2005).\u003c/li\u003e\n\u003cli\u003eGoldenberg, R. L., Culhane, J. F., Iams, J. D. \u0026amp; Romero, R. Epidemiology and causes of preterm birth. \u003cem\u003eThe Lancet\u003c/em\u003e \u003cstrong\u003e371\u003c/strong\u003e, 75-84 (2008).\u003c/li\u003e\n\u003cli\u003eMortality, G. B. D. \u0026amp; Causes of Death, C. Global, regional, and national life expectancy, all-cause mortality, and cause-specific mortality for 249 causes of death, 1980-2015: a systematic analysis for the Global Burden of Disease Study 2015. \u003cem\u003eLancet\u003c/em\u003e \u003cstrong\u003e388\u003c/strong\u003e, 1459-1544 (2016).\u003c/li\u003e\n\u003cli\u003eChawanpaiboon, S.\u003cem\u003e et al.\u003c/em\u003e Global, regional, and national estimates of levels of preterm birth in 2014: a systematic review and modelling analysis. \u003cem\u003eThe Lancet Global Health\u003c/em\u003e \u003cstrong\u003e7\u003c/strong\u003e, e37-e46 (2019).\u003c/li\u003e\n\u003cli\u003eJuan, J.\u003cem\u003e et al.\u003c/em\u003e Effect of coronavirus disease 2019 (COVID-19) on maternal, perinatal and neonatal outcome: systematic review. \u003cem\u003eUltrasound Obstet Gynecol\u003c/em\u003e \u003cstrong\u003e56\u003c/strong\u003e, 15-27 (2020).\u003c/li\u003e\n\u003cli\u003eHedermann, G.\u003cem\u003e et al.\u003c/em\u003e Danish premature birth rates during the COVID-19 lockdown. \u003cem\u003eArch Dis Child Fetal Neonatal Ed\u003c/em\u003e \u003cstrong\u003e106\u003c/strong\u003e, 93-95 (2021).\u003c/li\u003e\n\u003cli\u003eHwang, J.\u003cem\u003e et al.\u003c/em\u003e Changes in preterm birth and birthweight during the SARS-CoV-2 pandemic: a nationwide study in South Korea. \u003cem\u003eSci Rep\u003c/em\u003e \u003cstrong\u003e12\u003c/strong\u003e, 16288 (2022).\u003c/li\u003e\n\u003cli\u003eJin, J. H., Lee, S. A. \u0026amp; Yoon, S. W. Medical Utilization and Costs in Preterm Infants in the First 6 Years of Life After Discharge From Neonatal Intensive Care Unit: A Nationwide Population-Based Study in Korea. \u003cem\u003eJ Korean Med Sci\u003c/em\u003e \u003cstrong\u003e37\u003c/strong\u003e, e93 (2022).\u003c/li\u003e\n\u003cli\u003eBae, C.-W. The history of neonatology in Korea. \u003cem\u003eJournal of the Korean Medical Association\u003c/em\u003e \u003cstrong\u003e59\u003c/strong\u003e (2016).\u003c/li\u003e\n\u003cli\u003eShim, J. W., Jin, H. S. \u0026amp; Bae, C. W. Changes in Survival Rate for Very-Low-Birth-Weight Infants in Korea: Comparison with Other Countries. \u003cem\u003eJ Korean Med Sci\u003c/em\u003e \u003cstrong\u003e30 Suppl 1\u003c/strong\u003e, S25-34 (2015).\u003c/li\u003e\n\u003cli\u003eSingh, D., Rana, K. S. \u0026amp; Mathai, S. Role of prophylactic surfactant in preterm infants. \u003cem\u003eMed J Armed Forces India\u003c/em\u003e \u003cstrong\u003e67\u003c/strong\u003e, 138-141 (2011).\u003c/li\u003e\n\u003cli\u003ePark, S. K.\u003cem\u003e et al.\u003c/em\u003e Effect of Synagis\u0026reg; (palivizumab) prophylaxis on readmission due to respiratory syncytial virus in very low birth weight infants. \u003cem\u003eKorean Journal of Pediatrics\u003c/em\u003e \u003cstrong\u003e53\u003c/strong\u003e (2010).\u003c/li\u003e\n\u003cli\u003eOECD. \u003cem\u003eHealth at a Glance 2017\u003c/em\u003e2017).\u003c/li\u003e\n\u003cli\u003eJohnston, K. M.\u003cem\u003e et al.\u003c/em\u003e The economic burden of prematurity in Canada. \u003cem\u003eBMC Pediatr\u003c/em\u003e \u003cstrong\u003e14\u003c/strong\u003e, 93 (2014).\u003c/li\u003e\n\u003cli\u003eRolnitsky, A., Unger, S., Urbach, D. \u0026amp; Bell, C. M. The price of neonatal intensive care outcomes - in-hospital costs of morbidities related to preterm birth. \u003cem\u003eFront Pediatr\u003c/em\u003e \u003cstrong\u003e11\u003c/strong\u003e, 1068367 (2023).\u003c/li\u003e\n\u003cli\u003eRolnitsky, A., Unger, S. L., Urbach, D. R. \u0026amp; Bell, C. M. Cost of neonatal intensive care for extremely preterm infants in Canada. \u003cem\u003eTransl Pediatr\u003c/em\u003e \u003cstrong\u003e10\u003c/strong\u003e, 1630-1636 (2021).\u003c/li\u003e\n\u003cli\u003eBeam, A. L.\u003cem\u003e et al.\u003c/em\u003e Estimates of healthcare spending for preterm and low-birthweight infants in a commercially insured population: 2008-2016. \u003cem\u003eJ Perinatol\u003c/em\u003e \u003cstrong\u003e40\u003c/strong\u003e, 1091-1099 (2020).\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Supplementary Table","content":"\u003cp\u003eSupplementary Table 1 are not available with this version.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Prematurity, Cost, health insurance, hospitalization, preterm birth","lastPublishedDoi":"10.21203/rs.3.rs-3349473/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3349473/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eObjective: \u003c/strong\u003eDespite the decline in the overall birth rate, increasing preterm births and associated medical costs pose a national concern\u003cstrong\u003e. \u003c/strong\u003eWe analyze hospitalization costs covered by national public insurance for preterm infants.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods: \u003c/strong\u003ePopulation-based data, obtained from the National Health Insurance Service (NHIS), which is operated by the Health Insurance Review and Assessment Service, were used for the study. Preterm births from January 1, 2008 to December 31, 2020 were included, using International Classification of Diseases and Related Health Problems, 10\u003csup\u003eth \u003c/sup\u003eedition (P0.72, extremely preterm \u0026lt;28 weeks gestational age, P07.3, non-extremely preterm). The primary outcomes related to cost from the first hospitalization due to preterm births and medication, and laboratory, radiological, and functional tests by gestational age and birth weight. Additionally, we assessed the readmission rates of preterm infants and the associated medical costs.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults: \u003c/strong\u003eA total of 5,312,886 live infants were born, of which 90,575 were claimed as preterm birth hospitalization. The total medical cost per patient increased almost three-fold from $7,390.90 to $20,209.59 from 2008 to 2020; for the extremely preterm group, it increased four-fold ($13,961.03 to $55,984.47 $). The readmission rate within 90 days of discharge was 62.5%; however, a greater proportion of the extremely preterm, as compared to the non-extremely preterm (16.1% vs. 8.32%, \u003cem\u003eP \u0026lt; \u003c/em\u003e0.001) group was readmitted within 30 days,. The extremely preterm group also incurred higher costs associated with readmission (mean $4293.8 vs. $2975.4, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.001).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion: \u003c/strong\u003eThis study reveals not only the increase in preterm birth rate in South Korea, but also in the associated medical costs. Further attention should be paid to efficient resource allocation at the national level to relieve the medical burden of preterm births.\u003c/p\u003e","manuscriptTitle":"Rising Public Cost of Preterm Infant Hospitalization: A nationwide observational study in South Korea","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2023-09-29 17:54:02","doi":"10.21203/rs.3.rs-3349473/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-04-30T13:55:03+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-04-30T06:24:22+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"c5cfe90e-2235-4d18-a13f-9241e874c14d","date":"2024-04-26T05:13:04+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2023-12-22T13:31:07+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"fb07abf2-e4d9-49ef-a2cb-ab7bcb06bd83","date":"2023-12-05T12:12:51+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2023-11-16T16:58:00+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2023-10-25T12:05:42+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2023-09-23T02:34:39+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2023-09-23T02:32:33+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2023-09-12T17:03:36+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"113598f5-1e7a-40c8-93dc-907618db7b2d","owner":[],"postedDate":"September 29th, 2023","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":25053254,"name":"Health sciences/Medical research/Epidemiology"},{"id":25053255,"name":"Health sciences/Health care/Health policy"}],"tags":[],"updatedAt":"2025-04-28T15:58:56+00:00","versionOfRecord":{"articleIdentity":"rs-3349473","link":"https://doi.org/10.1038/s41598-025-98868-2","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2025-04-24 15:56:55","publishedOnDateReadable":"April 24th, 2025"},"versionCreatedAt":"2023-09-29 17:54:02","video":"","vorDoi":"10.1038/s41598-025-98868-2","vorDoiUrl":"https://doi.org/10.1038/s41598-025-98868-2","workflowStages":[]},"version":"v1","identity":"rs-3349473","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3349473","identity":"rs-3349473","version":["v1"]},"buildId":"WrCJVZZCHTDjtuVLN7oU0","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}