Background: Menorrhagia is a common cause of iron deficiency anemia (IDA) in premenopausal women. However, the effects of menorrhagia on IDA in premenopausal women have been underestimated compared to those on other IDA-related disorders (IRDs) such as gastrointestinal malignancies (GIMs). To better understand the relationship between menorrhagia and IDA in premenopausal women, we analyzed the National Health Insurance Service-National Health Information Database (NHIS-NHID). Methods: From 2005 to 2008, data about women between the age of 20 and 59 years were extracted from the NHIS-NHID to create a propensity score-matched case (IDA) and control group. The annual incidence of IDA was calculated per age group. A 10-year follow up of the study population was determined to detect IRDs in case and control groups. We compared the risk of detection (ROD) of IRDs, including GIM and gynecological disorders associated with menorrhagia - leiomyoma of uterus (LM) and adenomyosis (AM), in the case and the control group. Results: From 2005 to 2008, women diagnosed with IDA (n = 535,249) and healthy women as a control group (n = 1,070,498) were identified from the NHIS-NHID. The annual incidence of IDA was 767.4 (2005), 948.7 (2006), 981.6 (2007), and 897.7 (2008) per 100,000 women.The age distribution of IDA was similar each year; IDA was common in women aged 30–39 years (36–37%) and 40–49 years (30–32%), and its incidence was significantly decreased in women aged 50–59 years (< 10%). The ROD of IRDs were significantly higher in the IDA group than in the control group (LM: 20.8% vs. 6.9%, AM: 5.6% vs. 1.6%, and GIM: 2.6% vs.0.7%). The corresponding hazard ratios were 3.89 (95% confidence interval [CI], 3.85–3.93) for LM, 4.99 (95% CI, 4.90–5.09) for AM, and 3.43 (95% CI, 3.32–3.55) for GIM. The ROD of the IRDs varied; the ROD of LM in the IDA group increased with age and decreased in the age group 50–59 years. AM was more frequently detected in women with IDA aged 30–39 years and less in women older than 40 years. The frequency of GIM increased with age. Conclusion In this study, we found that the gynecologic disease is the main cause of IDA in premenopausal women. Gynecological evaluations should be performed more actively in the clinic to prevent and control IDA and IRDs.

Background: This study aimed to examine the association of serum uric acid levels with incident cardiovascular disease and mortality in Korean adults without gout. Methods: This large longitudinal cohort study included adults aged > 19 years who had serum uric acid levels measured at least once at the National Health Insurance Service Ilsan Hospital from January 1, 2006 to December 31, 2015. Longitudinal data on person-level cardiovascular disease and cardiovascular mortality were linked to the National Health Insurance Service claims database and National Death Index. Results: Among a total of 92,454 study participants with a median follow-up of 4.7 years, 7,670 (8.3%) composite events of cardiovascular disease or cardiovascular mortality were observed. Multivariable Cox proportional-hazards models revealed that each 1 mg/dL increment in uric acid level was associated with a 6% higher risk of composite outcomes.Compared with that for the uric acid level category of 4.0 to < 5.0 mg/dL, adjusted hazard ratios (95% confidence interval) for uric acid level categories of 5.0 to < 6.0, 6.0 to < 7.0, and ≥ 7.0 mg/dL were 1.10 (1.04–1.18), 1.20 (1.11–1.30), and 1.36 (1.25–1.47), respectively. In the secondary analyses for cardiovascular disease or cardiovascular mortality examined separately, a higher uric acid level was similarly associated with a higher risk of each adverse outcome. These associations were generally consistent across clinically relevant subgroups. Conclusion A graded association was noted between serum uric acid levels and cardiovascular risk, suggesting that higher uric acid levels may adversely affect cardiovascular health and survival in individuals without gout.

Purpose: To report incidence rates of primary congenital glaucoma in Korea and evaluate comorbidity and mortality from 2001 to 2015. Methods: This study is a nationwide and retrospective population-based study. We used claims data from the Korean National Health Insurance Service database between 2001 and 2015. Data for all patients diagnosed with primary congenital glaucoma were retrieved using the Korean Electronic Data Interchange and Korean Standard Classification of Diseases-6 codes. Results: The number of patients with primary congenital glaucoma between 2001 and 2015 was 776, of which 437 were male (56.31%) and 339 were female (43.69%). The annual prevalence demonstrated a general decreasing trend since 2011, but this was not significant. Over the total survey period, the incidence rate was 11.0 per 100,000 births, with 12.0 cases among males and 10.0 among females. The incidence according to age was 518 (68.78%) patients at age 0, 112 (13.66%) at 1year, 70 (8.39%) at 2 years, and 76 (9.17%) at 3 years. Of the 776 patients diagnosed with primary congenital glaucoma in the study population, 27 died. The observed mortality per 100,000 people is about 10 times higher than that of the general infant and child population under the age of 4 years. Visual impairment was the most common accompanying disability, followed by brain lesion. Conclusions Our study’s estimates of the nationwide population-based incidence of primary congenital glaucoma in a Korean population will expand our understanding of the disease and allow healthcare systems to plan for primary congenital glaucoma.

PURPOSE: To examine changes in clinical practice patterns following the introduction of diagnosis-related groups (DRGs) under the fee-for-service payment system in July 2013 among Korean tertiary hospitals and to evaluate its effect on the quality of hospital care. MATERIALS AND METHODS: Using the 2012–2014 administrative database from National Health Insurance Service claim data, we reviewed medical information for 160400 patients who underwent cesarean sections (C-secs), hysterectomies, or adnexectomies at 43 tertiary hospitals. We compared changes in several variables, including length of stay, spillover, readmission rate, and the number of simultaneous and emergency operations, from before to after introduction of the DRGs. RESULTS: DRGs significantly reduced the length of stay of patients undergoing C-secs, hysterectomies, and adnexectomies (8.0±6.9 vs. 6.0±2.3 days, 7.4±3.5 vs. 6.4±2.7 days, 6.3±3.6 vs. 6.2±4.0 days, respectively, all p < 0.001). Readmission rates decreased after introduction of DRGs (2.13% vs. 1.19% for C-secs, 4.51% vs. 3.05% for hysterectomies, 4.77% vs. 2.65% for adnexectomies, all p < 0.001). Spillover rates did not change. Simultaneous surgeries, such as colpopexy and transobturator-tape procedures, during hysterectomies decreased, while colporrhaphy during hysterectomies and adnexectomies or myomectomies during C-secs did not change. The number of emergency operations for hysterectomies and adnexectomies decreased. CONCLUSION: Implementation of DRGs in the field of obstetrics and gynecology among Korean tertiary hospitals led to reductions in the length of stay without increasing outpatient visits and readmission rates. The number of simultaneous surgeries requiring expensive operative instruments and emergency operations decreased after introduction of the DRGs.
Cesarean Section ; Diagnosis-Related Groups* ; Emergencies ; Female ; Gynecology* ; Health Care Costs ; Humans ; Hysterectomy ; Length of Stay ; National Health Programs ; Obstetrics* ; Outpatients ; Practice Patterns, Physicians' ; Pregnancy ; Prospective Payment System ; Tertiary Care Centers*

Background/Aims: To investigate whether visceral fat area (VFA) measured by bioelectric impedance analysis (BIA) was associated with metabolic syndrome in subjects with and without obesity. Methods: A total 23,202 participants who underwent medical check-ups were assessed. Participants were stratified by body mass index (BMI) and VFA. We evaluated six different groups for metabolic syndrome: Group 1 (normal weight and low VFA), Group 2 (normal weight and high VFA), Group 3 (overweight and low VFA), Group 4 (overweight and high VFA), Group 5 (obesity and low VFA), and Group 6 (obesity and high VFA). Results: Metabolic syndrome traits and metabolic syndrome were significantly more prevalent in the high-VFA (≥ 100 cm2 ) subgroup in each BMI group. Adjusted logistic regression analyses revealed that the odds ratio for metabolic syndrome compared with Group 1 was the highest in Group 6 (24.53; 95% confidence interval [CI], 21.77 to 27.64). Notably, the odds ratio of Group 2 was higher than that of Group 3 (2.92; 95% CI, 2.30 to 3.69 vs. 2.57; 95% CI, 2.23 to 2.97). Conclusions Our study demonstrates that the combination of BMI assessment and VFA determination by BIA may be a useful method for predicting the risk of metabolic syndrome. The VFA by BIA may be a useful target for interventions to improve metabolic syndrome.

PURPOSE: This study aims to investigate the effects of smoking on the development of placenta-associated syndromes, including preeclampsia, abruptio placentae, and placenta previa, which share the common pathophysiology of vascular compromise of the placenta. METHODS: A total of 966,629 pregnancies identified from the Korean National Insurance Claims Database and the National Health Information Database were analyzed from 2010 to 2014. The adjusted odds ratio and attributable risk of smoking for the development of placenta-associated syndromes, such as preeclampsia, placenta previa, and abruptio placentae, were analyzed. Maternal age, alcohol consumption, exercise habit, and economic status were controlled as confounding variables. A binary logistic regression model was used, and simple and multiple logistic regression analyses were performed. RESULTS: Among 966,629 pregnancies, 11.86% of women were ever smokers. Ever smokers had a higher risk of developing placenta previa (adjusted odds ratio, 1.23; 95% confidence interval [CI], 1.18–1.29; adjusted attributable risk, 18.70%). The adjusted odds ratio of developing placenta-associated syndromes in ever smokers compared to nonsmokers over the age of 35 years with a low economic status was 1.32 (95% CI, 1.18–1.47), with an adjusted attributable risk of 23.95%. CONCLUSION: The risk of developing placenta-associated syndromes, such as preeclampsia, placenta previa, and abruptio placentae, is high in ever smokers. Pregnant ever smokers who are >35 years and belong to the lower one-third of the economic division require special care to prevent the development of placenta-associated syndromes.
Abruptio Placentae ; Alcohol Drinking ; Confounding Factors (Epidemiology) ; Female ; Humans ; Insurance ; Korea ; Logistic Models ; Maternal Age ; Odds Ratio ; Placenta ; Placenta Previa ; Pre-Eclampsia ; Pregnancy ; Smoke ; Smoking

OBJECTIVES: The escalating burden of cardiovascular disease (CVD) is a critical public health issue worldwide. CVD, especially acute myocardial infarction (AMI) and stroke, is the leading contributor to morbidity and mortality in Korea. We aimed to develop algorithms for identifying AMI and stroke events from the National Health Insurance Service (NHIS) database and validate these algorithms through medical record review. METHODS: We first established a concept and definition of “hospitalization episode,” taking into account the unique features of health claims-based NHIS database. We then developed first and recurrent event identification algorithms, separately for AMI and stroke, to determine whether each hospitalization episode represents a true incident case of AMI or stroke. Finally, we assessed our algorithms’ accuracy by calculating their positive predictive values (PPVs) based on medical records of algorithm- identified events. RESULTS: We developed identification algorithms for both AMI and stroke. To validate them, we conducted retrospective review of medical records for 3,140 algorithm-identified events (1,399 AMI and 1,741 stroke events) across 24 hospitals throughout Korea. The overall PPVs for the first and recurrent AMI events were around 92% and 78%, respectively, while those for the first and recurrent stroke events were around 88% and 81%, respectively. CONCLUSIONS We successfully developed algorithms for identifying AMI and stroke events. The algorithms demonstrated high accuracy, with PPVs of approximately 90% for first events and 80% for recurrent events. These findings indicate that our algorithms hold promise as an instrumental tool for the consistent and reliable production of national CVD statistics in Korea.