National population-based study of constipation in children in Korea, 2002-2013.

BACKGROUND: The purpose of this study is to estimate the overall prevalence and incidence of constipation in Korean children and adolescent based on health insurance claims data. METHODS: This study is a retrospective cohort study using the Korean National Health Insurance Service - National Sample Cohort from 2002 to 2013. Patients age less than 19 years old were selected, and the prevalence and incidence of constipation were estimated. RESULTS: The standardized incidence rate was 10.8 per 1,000 persons in 2004 to 14.3 per 1,000 persons in 2012. The standardized prevalence increased from 12.2 per persons in 2002 to 26.4 per persons in 2013. Females had a higher incidence rate and prevalence rate than males during the study period. The overall recurrence rates were 13.2%. The recurrence rates were 12.9% in males and 13.5% in females. The overall average constipation duration was 229 days. The duration was 222 days in males and 236 days in females. CONCLUSIONS: This is the first study to conduct a population-based study of all children in Korea with constipation. These data reveal the increasing burden and impact of constipation on children and could enable effective public and clinical health strategies to be planned.

The Estimated Prevalence and Incidence of Endometriosis With the Korean National Health Insurance Service-National Sample Cohort (NHIS-NSC): A National Population-Based Study.

BACKGROUND: The incidence and prevalence of endometriosis remain unclear due to diagnostic difficulties. Especially, there has been little information regarding the population-based epidemiology of endometriosis. The purpose of this study is to estimate the prevalence and incidence of endometriosis in Korea based on the health insurance claims data. METHODS: This study is a retrospective cohort study using the Korean National Health Insurance Service-National Sample Cohort, which correspond to approximately 1 million Korean populations from 2002 to 2013. Patients aged 15-54 years were selected, and the prevalence and incidence of endometriosis were estimated by time and age groups. RESULTS: The age-adjusted prevalence rate of endometriosis also increased from 2.12 per 1,000 persons (95% confidence interval [CI], 2.01-2.24) in 2002 to 3.56 per 1,000 persons (95% CI, 3.40-3.71) in 2013. The average adjusted incidence showed no statistically significant increase. However, the age-specific incidence of the 15-19 and 20-24 years age groups increased significantly from 0.24 and 1.29 per 1,000 persons in 2003 to 2.73 and 2.71 per 1,000 persons in 2013 (R2 = 0.93 and 0.77, P < 0.001), while the incidence rate of the age group 40-44 and 45-49 years decreased from 2.36 and 1.72 per 1,000 persons in 2003 to 0.81 and 0.27 per 1,000 persons in 2013 (R2 = 0.83 and 0.89, P < 0.001). CONCLUSION: The prevalence and incidence of endometriosis in Korean women were lower than that of previous reports in high-risk population studies. Furthermore, we found a significant increase in the diagnosis of endometriosis in younger age groups.

Factors influencing caregiver burden by dementia severity based on an online database from Seoul dementia management project in Korea.

BACKGROUNDS: As the prevalence of dementia rises, caregiver burden also increases in South Korea, especially for informal family caregivers. This study aimed to analyze factors affecting caregiver burden by the severity of dementia based on data of patients in Seoul. METHODS: A total of 12,292 individuals aged ≥65 years enrolled in the Seoul Dementia Management Project from 2010 to 2016 in an online database were selected. Caregiver's burden was assessed using the Korea version of Zarit Burden Interview. Multiple regression analyses were performed to determine factors associated with primary caregiver's burden after stratifying the severity of dementia. RESULTS: Most patients showed moderate levels of cognitive impairment (49.4%), behavior problems (82.6%), and ADL dependency (73.6%). After stratifying the severity of dementia, caregivers caring for patients with mild symptoms of dementia were experienced with higher caregiver burden if patients were under a lower score of IADL. Significant factors for caregiver burden among caregivers supporting patients with moderate symptoms of dementia include caregivers' residence with patients, subjective health status, and co-work with secondary caregivers. Lastly, caregivers for patients with severe dementia symptoms experienced a higher caregiver burden from limited cognitive function, problematic behavior, and caregivers' negative health status. CONCLUSION: In terms of sample size, this study had far more patients than any other domestic or international study. It was meaningful in that it analyzed characteristics of patients with dementia and caregivers affecting the burden of caregivers in Korea. Intensive social supports with multiple coping strategies focusing on different levels of patients' clinical symptoms and caregivers' needs should be planned to relieve the caregiver burden.

The effect of the look-back period for estimating incidence using administrative data.

BACKGROUND: The look-back period is needed to define baseline population for estimating incidence. However, short look-back period is known to overestimate incidence of diseases misclassifying prevalent cases to incident cases. The purpose of this study is to evaluate the impact of the various length of look-back period on the observed incidences of uterine leiomyoma, endometriosis and adenomyosis, and to estimate true incidences considering the misclassification errors in the longitudinal administrative data in Korea. METHODS: A total of 319,608 women between 15 to 54 years of age in 2002 were selected from Korea National Health Insurance Services (KNHIS) cohort database. In order to minimize misclassification bias incurred when applying various length of look-back period, we used 11 years of claim data to estimate the incidence by equally setting the look-back period to 11 years for each year using prediction model. The association between the year of diagnosis and the number of prevalent cases with the misclassification rates by each look-back period was investigated. Based on the findings, prediction models on the proportion of misclassified incident cases were developed using multiple linear regression. RESULTS: The proportion of misclassified incident cases of uterine leiomyoma, endometriosis and adenomyosis were 32.8, 10.4 and 13.6% respectively for the one-year look-back period in 2003. These numbers decreased to 6.3% in uterine leiomyoma and - 0.8% in both endometriosis and adenomyosis using all available look-back periods (11 years) in 2013. CONCLUSION: This study demonstrates approaches for estimating incidences considering the different proportion of misclassified cases for various length of look-back period. Although the prediction model used for estimation showed strong R-squared values, follow-up studies are required for validation of the study results.

Prevalence, incidence, and treatment trends of adenomyosis in South Korean women for 15 years: A national population-based study.

OBJECTIVE: Adenomyosis is associated with female infertility worldwide. With improvements in imaging methods, such as pelvic magnetic resonance imaging, the diagnosis and treatment of adenomyosis have changed. This study aimed to evaluate the overall prevalence, incidence, and treatment trends of adenomyosis in South Korea using data from the Korean National Health Insurance Service Database (NHIS). METHODS: Data were collected from the Korean NHIS, a population-based complete enumeration database. A total of 678 641 women aged 11-55 years diagnosed with adenomyosis (N80.0 ICD-10 code) from the database from 2002 to 2016 were enrolled. After applying a one-year look-back method, 629 592 patients were analyzed to estimate the prevalence, incidence, and treatment trends of adenomyosis. RESULTS: The overall prevalence during the study period was 3.86 per 1000 people. The prevalence of adenomyosis has increased from 1.42 per 1000 individuals in 2002 to 7.50 per 1000 individuals in 2016. The crude annual incidence rate of adenomyosis was 1.62 per 1000 people in 2003, which increased to 4.12 per 1000 people in 2016. In addition, the proportion of uterus-preserving surgeries in adenomyosis treatments has increased from 7.51% to 21.29% over 15 years. CONCLUSION: The prevalence and incidence of adenomyosis in South Korea increased between 2002 and 2016. Furthermore, the proportion of uterus-preserving surgeries and progestin prescriptions for adenomyosis treatment has increased. We expect that our findings will raise awareness of the necessity for fertility preservation through earlier diagnosis and proper management of patients with adenomyosis.

Estimated Prevalence and Incidence of Uterine Leiomyoma, and Its Treatment Trend in South Korean Women for 12 years: A National Population-Based Study.

Background: Although uterine leiomyoma causes many problems, including infertility, there are few studies that have investigated the epidemiologic characteristics of uterine leiomyoma in South Korea. The aim of this study is to estimate the prevalence and incidence of uterine leiomyoma in South Korea and analyze the treatment trends. Materials and Methods: Women of reproductive age (15-54 years) were selected from the Korean National Health Insurance Service (NHIS) sample cohort dataset, which was collected from 2002 to 2013. Patients with uterine leiomyoma were identified by ICD-10 (International Codes of Disease, 10th Edition) and intervention codes. Prevalence and incidence were calculated from the NHIS cohort dataset and the treatment trends were analyzed for diagnosed patients. Results: The prevalence in overall age groups increased from 0.96% in 2002 to 2.43% in 2013, and the 1-year incidences of all age groups increased. The 26-30 age group showed the highest rate of 1-year incidence increase (2.14-folds, 0.33% in 2003 to 0.70% in 2013). The proportion of myomectomy increased from 22% in 2002 to 49% in 2013, whereas the proportion of hysterectomy decreased from 78% to 45%. Conclusions: The prevalence and incidence of uterine leiomyoma are increasing in South Korea as time progresses, and the rate of incidence increase is higher in younger reproductive women. Overall trends in uterine leiomyoma treatment are shifting to the methods of the saving uterus.