Incidence of invasive fungal diseases in inflammatory bowel disease patients: A nationwide study in South Korea.

BACKGROUND: Limited reports exist regarding invasive fungal diseases (IFDs) in inflammatory bowel disease (IBD) patients. OBJECTIVES: This study aims to investigate the incidence and risk factors of IFDs, specifically invasive candidiasis, aspergillosis and pneumocystosis, in IBD patients in South Korea using nationwide data. PATIENTS/METHODS: A population-based retrospective cohort of 42,913 IBD patients between January 2010 and December 2018 was evaluated using the Health Insurance Review and Assessment database. The primary outcome was the incidence of IFDs, including invasive candidiasis, aspergillosis and pneumocystosis, while the secondary outcome involved analysing the risk factors associated with each specific infection. RESULTS: The study included a total of 42,913 IBD patients, with 29,909 (69.7%) diagnosed with ulcerative colitis (UC) and 13,004 (30.3%) diagnosed with Crohn's disease (CD). IFDs occurred in 166 IBD patients (0.4%), with 93 cases in UC patients and 73 cases in CD patients. The incidence rates of invasive candidiasis, aspergillosis and pneumocystosis in IBD patients were 0.71 per 1000 person-years (PYs), 0.15 per 1000 PYs and 0.12 per 1000 PYs, respectively. The cumulative incidence of invasive candidiasis (adjusted p-value <.001) and Pneumocystosis (adjusted p-value = .012) was found to be higher in CD patients than in UC patients. Each IFD had different risk factors, including IBD subtypes, age at diagnosis, anti-tumour necrotic factor agents or the Charlson comorbidity index. CONCLUSION: Based on nationwide data in South Korea, this study shows that IFDs occur consistently in patients with IBD, albeit with a low frequency.

Comparison of a Tobacco-Specific Carcinogen in Tobacco Cigarette, Electronic Cigarette, and Dual Users.

BACKGROUND: 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) is known as a lung carcinogen. The objective of this study was to investigate associations of urine NNAL concentrations and smoking status. METHODS: This was a cross-sectionally designed study based on data from the 2016-2018 Korean National Health and Nutrition Examination Survey. A total of 2,845 participants were classified into past-smoker, electronic cigarette (e-cigar) only, dual-user, and cigarette only smoker groups. All sampling and weight variables were stratified and analysis was conducted accounting for the complex sampling design. Analysis of covariance was used to compare the geometric mean of urine NNAL concentrations and log-transformed urine NNAL level among smoking status with weighted survey design. Post hoc paired comparisons with Bonferroni adjustment was performed according to smoking status. RESULTS: The estimated geometric mean concentrations of urine NNAL were 1.974 ± 0.091, 14.349 ± 5.218, 89.002 ± 11.444, and 117.597 ± 5.459 pg/mL in past-smoker, e-cigar only, dual-user, and cigarette only smoker groups, respectively. After fully adjusting, log-transformed urine NNAL level was significantly different among groups (P < 0.001). Compared with the past-smoker group, e-cigar only, dual-user, and cigarette only smoker groups showed significantly higher log-transformed urine NNAL concentrations in post hoc test (all P < 0.05). CONCLUSION: E-cigar only, dual-user, and cigarette only smoker groups showed significantly higher geometric mean concentrations of urine NNAL than the past-smoker group. Conventional cigarette, dual users, and e-cigar users can potentially show harmful health effects from NNAL.

Risk Factors for the Occurrence and Severity of Vertebral Fractures in Inflammatory Bowel Disease Patients: A Nationwide Population-Based Cohort Study.

BACKGROUND: The risk of vertebral fractures is increased in inflammatory bowel disease (IBD) patients. However, whether the severity of vertebral fractures differs between IBD patients and the general population, or between patients with Crohn's disease (CD) and ulcerative colitis (UC), is unknown. METHODS: We investigated risk factors associated with the occurrence and severity of vertebral fractures in IBD patients using The National Healthcare Insurance Service (NHIS) database. We defined the patients who underwent vertebroplasty or kyphoplasty after being diagnosed with a vertebral fracture as having a severe vertebral fracture than those with only diagnosis codes. RESULTS: From 2008 to 2018, there were 33,778 patients with IBD (24,370 UC patients and 9,408 CD patients) and 101,265 patients in the reference population. The incidence rate ratio of vertebral fractures in the IBD patients was 1.27 per 1,000 person-years (95% confidence interval [CI], 1.26-1.27). The risk of vertebral fracture was higher in CD and UC patients than in the matched reference group (hazard ratio [HR], 1.59; 95% CI, 1.31-1.92; P < 0.001 and HR, 1.26; 95% CI, 1.14-1.41; P < 0.001, respectively). In a multivariate analysis, the occurrence of vertebral fracture was associated with CD (HR, 1.31; 95% CI, 1.08-1.59; P = 0.006), older age (CD: HR, 1.09; 95% CI, 1.08-1.09; P < 0.001 and UC: HR, 1.09; 95% CI, 1.08-1.09; P < 0.001), female sex (CD: HR, 1.81; 95% CI, 1.63-2.01; P < 0.001 and UC: HR, 2.02; 95% CI, 1.83-2.22; P < 0.001), high Charlson Comorbidity Index (CCI) score (CD: HR, 1.42; 95% CI, 1.23-1.63; P < 0.001 and UC: HR, 1.46; 95% CI, 1.29-1.65, P < 0.001), and long-term steroid use (CD: HR, 3.71; 95% CI, 2.84-3.37; P < 0.001 and UC: HR, 3.88; 95% CI, 3.07-4.91; P < 0.001). The severity of vertebral fractures was associated with IBD (CD: HR, 1.82; 95% CI, 1.17-2.83; P = 0.008 and UC: HR, 1.49; 95% CI, 1.17-1.89; P < 0.001) and older age (HR, 1.06; 95% CI, 1.05-1.07; P < 0.001). CONCLUSION: Vertebral fractures occur frequently and more severely in IBD patients, particularly those with CD. Therefore, we suggest monitoring of bone density, regular vitamin D supply, and reducing the use of corticosteroids to prevent vertebral fractures in IBD patients who are older, female, or have comorbidities.

The Prevalence and Risk Factors of Clostridioides difficile Infection in Inflammatory Bowel Disease: 10-Year South Korean Experience Based on the National Database.

BACKGROUND: Few studies evaluate the epidemiology and risk factors of Clostridioides difficile infection (CDI) in Asian patients with inflammatory bowel disease (IBD). We investigated the year-end prevalence, cumulative incidence and risk factors of CDI in Asian patients with IBD using a large-scale population-based cohort in Korea. METHODS: Using the National Health Insurance Service database, we identified patients with IBD and sex- and age-matched controls without IBD between 2008 and 2018. The year-end prevalence and cumulative incidence of CDI were compared among patients with Crohn's disease (CD) and ulcerative colitis (UC) with controls. The risk factors for CDI were evaluated. RESULTS: Among the 54,836 patients with IBD and 109,178 controls, CDI occurred in 293 patients with IBD and 87 controls. The annual year-end prevalence of CDI in patients with IBD increased from 8.6/10,000 persons in 2008 to 22.3/10,000 persons in 2018. The risk of CDI was higher in both patients with CD and UC than that in the matched controls (hazard ratio [HR], 7.285; 95% confidence interval [CI], 5.388-9.851; P < 0.001 and HR, 7.487; 95% CI, 5.796-9.670; P < 0.001, respectively). Among patients with IBD, the risk factors for CDI included older age, female sex, high Charlson comorbidity index score, and IBD-related medications including oral 5-aminosalicylic acid, immunomodulatory agents, biologics, and steroids used for > 90 days. CONCLUSION: The risk of CDI in Korean patients with IBD was approximately seven times higher than that in controls without IBD, and the annual year-end prevalence of CDI continuously increased from 2008 to 2018.

Colonoscopy decreases mortality in colorectal cancer patients compared with fecal immunochemical test.

BACKGROUND AND AIM: Colonoscopy and fecal immunochemical test (FIT) are commonly used screening methods for the detection of colorectal cancer (CRC), but their effects on survival have not been compared. We compared survival outcomes in patients with CRC according to the exposure history to colonoscopy or FIT before diagnosis of CRC. METHODS: We performed a nationwide population-based retrospective cohort study using Korean national-insurance claims data. In total, 24 875 patients with CRC diagnosed in 2012 were included. The patients were divided into three groups in terms of examinations performed during the 10 years prior to CRC diagnosis: the colonoscopy group, the FIT group, and the never-screened group. Survival outcomes were compared among the three groups. The colonoscopy group and FIT group were matched using propensity score-matching method. RESULTS: The cohort consisted of 9619 patients in the colonoscopy group, 6936 patients in the FIT group, and 8320 patients in the never-screened group. The 5-year overall survival rates were 74.1% in the colonoscopy group, 65.9% in the FIT group, and 59.6% in the never-screened group (P < 0.001). The adjusted hazard ratios for death were 0.56 (95% confidence interval [CI], 0.53-0.59) in the colonoscopy group and 0.78 (95% CI, 0.74-0.82) in the FIT group compared with the never-screened group. In the matched cohort, the adjusted hazard ratios for death was 0.76 (95% CI, 0.72-0.81) in the colonoscopy group compared with the FIT group. CONCLUSION: Colonoscopy is a more effective method for reducing mortality in patients with CRC compared with FIT.

Associations between suicidal ideation and health-related quality of life among community-dwelling stroke survivors: 2013-2017 Korea National Health and Nutrition Examination Survey.

PURPOSE: The study aimed to identify differences between individuals with stroke and the general population regarding socioeconomic, mental health, and Health-related quality of life (HRQOL) factors, and associations among Suicidal ideation (SI), HRQOL, and mental health. METHODS: Data of individuals with stroke (n = 592) and without stroke (n = 23,562) aged 20 or older from the 2013-2017 Korea National Health and Nutrition Examination Survey were analyzed. Chi-square tests examined differences in socioeconomic status, mental health, and HRQOL (EQ-5D) between groups. Independent associations between each EQ-5D dimension and SI were analyzed through multivariable logistic regression. RESULTS: Individuals with stroke were more likely to have problems on all EQ-5D dimensions. Significant univariate associations were identified between four EQ-5D dimensions and SI among individuals with stroke. Pain/discomfort (odds ratio [OR] = 1.32; 95% confidence interval [CI], 1.01-1.75, p = 0.048) and anxiety/depression (OR = 4.66; 95% CI, 3.69-5.89, p < .0001) of the EQ-5D were associated with SI when adjusting for all socioeconomic variables; anxiety/depression (OR = 2.80; 95% CI, 2.18-3.60, p < .0001) was the only risk factor for SI after controlling for socioeconomic and mental health variables. CONCLUSION: Individuals with stroke showed higher rates for problems on the EQ-5D, SI, and depression compared to the general population. They also demonstrated significant associations between SI and each EQ-5D dimension except physical activity, especially pain/discomfort and depression/anxiety. The study's findings can be referred to when predicting suicide risk in individuals with stroke by analyzing their EQ-5D scores.

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.

One-year changes in the pediatric emergency department caused by prolonged coronavirus disease 2019 pandemic.

BACKGROUND: With the coronavirus disease 2019 (COVID-19) pandemic lasting for more than a year, it is imperative to identify the associated changes in the use of emergency medical care for efficient operation of the pediatric emergency department (PED). This study was conducted to determine the long-term impact of the COVID-19 pandemic on patterns of PED visits. METHODS: This is a retrospective observational study of visits to the PED of six hospitals, between January 1, 2017, and December 31, 2020. We compared changes in the characteristics of patients before and during the COVID-19 pandemic. RESULTS: A total of 245 022 visits were included in this analysis. After the first case of COVID-19 was reported in Korea, we observed a significant decrease (54.2%) in PED visits compared with the annual average number of visits in the previous 3 years. Since then, the weekly number of PED visits decreased by 11.9 person/week (95% CI: -15.3--8.4, P < 0.001), which included an increase of 0.21% (95% CI: 0.15%-0.26%, P < 0.001) per week in high acuity patients. From 2017 to 2020, the proportion of infectious respiratory diseases by year was 25.9%, 27.0%, 28.6%, and 16.3%, respectively, demonstrating a significant decrease in 2020 (P < 0.001). CONCLUSIONS: During the COVID-19 pandemic, the number of patient visits to PEDs continues to decline, especially among those with infectious diseases. However, the disease severity of patients has gradually increased. There has been a change in the characteristics of visits to PEDs after COVID-19 which will require an appropriate response from a long-term perspective.

Changes in the Clinical Characteristics of Kawasaki Disease After Coronavirus Disease (COVID-19) Pandemic: A Database Analysis.

BACKGROUND: The impact of the coronavirus disease 2019 (COVID-19) pandemic on Kawasaki disease (KD) has not yet been established. We investigated changes in the observed number and severity of KD cases and accompanying coronary artery complications during the COVID-19 pandemic in Korea. METHODS: This retrospective observational study included patients aged < 18 years with acute-phase KD diagnosed between March 2018 and February 2021. Data were extracted from the Clinical Data Warehouse that houses data from five affiliated university hospitals in Korea. We analyzed changes in the number of patient admissions and clinical characteristics, including cardiac complications, before and after the onset of the COVID-19 pandemic. RESULTS: A total of 475 admissions were included in the analysis. After March 2020, we observed a significant decrease of 33% in the number of hospitalizations for KD compared with the average number of hospitalizations during the previous 2 years. The number of admissions per month significantly decreased by 7.9 persons/month (95% confidence interval, -13.8 to -2.0; P < 0.05) compared with that before COVID-19. By contrast, the proportion of patients aged < 1 year with KD increased. The proportion of patients with refractory KD and the rate of cardiac complications did not change significantly. CONCLUSION: Since the onset of the COVID-19 pandemic, the total number of hospital admissions for KD has decreased in Korea. Although the proportion of admissions of infants aged < 1 year increased, no changes were observed in clinical courses and complications.

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 determinants of caregiver use and its costs for elderly inpatients in Korea: a study applying Andersen's behavioral model of health care utilization and replacement cost method.

OBJECTIVES: The average annual healthcare expenditure among elderly patients in Korea is increasing rapidly in indirect healthcare sectors, requiring an understanding of factors related to the use of both formal and informal caregivers. This study analyzed the characteristics of caregiver use and caregiving costs among elderly patients hospitalized due to acute illness or exacerbation of chronic diseases. METHODS: A total of 819 study participants were selected from the 2017 Korea Health Panel Study Data. Replacement costing methods were applied to estimate the hours of informal caregiver assistance received by elderly inpatients. Elderly inpatients' predisposing, enabling, and need factors were studied to identify the relationship between caregiver uses, based on Andersen's behavior model. A two-part model was applied to analyze the factors related to care receipt and to estimate the incremental costs of care. RESULTS: Elderly inpatients who used tertiary hospitals (OR: 2.77, p-value < 0.00) and received financial support (OR: 2.68, p-value < 0.00) were more likely to receive support from a caregiver. However, elderly inpatients living alone were lesser to do so (OR: 0.49, p-value < 0.00). Elderly inpatients with Medicaid insurance (ß:0.54, p-value = 0.02) or financial aid (ß: 0.64, p-value < 0.00) had a statistically positive association with spending more on caregiving costs. Additionally, financial support receivers had incremental costs of $627 in caregiving costs than nonreceivers. CONCLUSIONS: This study presented significant socioenvironmental characteristics of formal and informal caregiver use and the related expenditures. Healthcare management plans that encompass multiple social levels should be implemented to ease the caregiver burden. TRIAL REGISTRATION: Retrospectively registered.

Analysis of Pediatric Surgery Using the National Healthcare Insurance Service Database in Korea: How Many Pediatric Surgeons Do We Need in Korea?

BACKGROUND: In the past, general surgeons (GSs) without a pediatric surgical subspecialty often performed surgery on children and, even now, GSs are performing many pediatric surgeries. We aimed to investigate the involvement of pediatric surgeons (PSs) and GSs in pediatric surgery, compare the outcomes of surgery in the neonatal intensive care unit (NICU), and estimate the appropriate PS workforce in Korea. METHODS: We used surgical data from the National Health Insurance Service database that was collected from patients under the age of 19 years in hospitals nationwide from January 2002 to December 2017. In this database, we found 37 hospitals where PSs worked by using the index operation (congenital diaphragmatic hernia, esophageal atresia, hypertrophic pyloric stenosis, Hirschsprung's disease, abdominal wall defect, jejunoileal atresia, malrotation, anorectal malformation, and biliary atresia). It was assumed that the surgery in the 37 hospitals was performed by PS and that the surgery in other hospitals was performed by GS. Mortality was analyzed to compare the outcomes of acute abdominal surgery in the NICU. We estimated the number of PS currently needed in Korea for each situation under the assumption that PS would perform all operations for the index operation, main pediatric diseases (index operation + gastroesophageal reflux disease, choledochal cyst, inguinal hernia, and appendicitis), acute abdominal surgery in the NICU, and all pediatric surgeries. Additionally, we estimated the appropriate number of PS required for more advanced pediatric surgery in the future. RESULTS: The number of pediatric surgeries from 2002 to 2017 increased by 124%. Approximately 10.25% of the total pediatric surgeries were performed by PSs, and the percentage of the surgery performed by PSs increased from 8.32% in 2002 to 15.92% in 2017. The percentage of index operations performed by PSs annually was 62.44% in average. It was only 47.81% in 2002, and increased to 88.79% in 2017. During the last 5 years of the study period, the average annual number of surgeries for main pediatric diseases was approximately 33,228. The ratio of the number of surgeries performed by PS vs. GS steadily increased in main pediatric diseases, however, the ratio of the number of surgery performed by PS for inguinal hernia and appendicitis remained low in the most recent years. The percentage of the number of acute abdominal surgery performed by PS in the NICU was 44% in 2002, but it had recently risen to 89.7%. After 30 days of birth, mortality was significantly lower in all groups that were operated on by PS, rather than GS, during the last 5 years. In 2019, 49 PSs who were under the age of 65 years were actively working in Korea. Assuming that all pediatric surgeries of the patients under the age of 19 years should be performed by PS, the minimum number of PS currently required was about 63 if they perform all of the index operations, the main pediatric surgery was about 209, the NICU operation was about 63, and the all pediatric surgeries was about 366. Additionally, it was determined that approximately 165 to 206 PS will be appropriate for Korea to implement more advanced pediatric surgery in the future. CONCLUSION: The proportion of the pediatric surgery performed by PS rather than GS is increasing in Korea, but it is still widely performed by GS. PSs have better operative outcomes for acute abdominal surgery in the NICU than GSs. We believe that at least the index operation or the NICU operation should be performed by PS for better outcome, and that a minimum of 63 PSs are needed in Korea to do so. In addition, approximately 200 PSs will be required in Korea in order to manage main pediatric diseases and to achieve more advanced pediatric surgery in the future.

Assessing the performance of a method for case-mix adjustment in the Korean Diagnosis-Related Groups (KDRG) system and its policy implications.

BACKGROUND: To evaluate the performance of the patient clinical complexity level (PCCL) mechanism, which is the patient-level complexity adjustment factor within the Korean Diagnosis-Related Groups (KDRG) patient classification system, in explaining the variation in resource consumption within age adjacent diagnosis-related groups (AADRGs). METHODS: We used the inpatient claims data from a public hospital in Korea from 1 January 2017 to 30 June 2019, with 18 846 claims and 138 AADRGs. The differences in the total average payment between the four PCCL levels for each AADRG was tested using ANOVA and Duncan's post hoc test. The three patterns of differences with R-squared were as follows: the PCCL reflected the complexity well (valid); the average payment for PCCL 2, 3, and 4 was greater than PCCL 0 (partially valid); the PCCL did not reflect the complexity (not valid). RESULTS: There were 9 (6.52%), 26 (18.84%), and 103 (74.64%) ADRGs included in the valid, partially valid, and not valid categories, respectively. The average R-squared values were 32.18, 40.81, and 35.41%, respectively, with an average R-squared for all patterns of 36.21%. CONCLUSIONS: Adjustment using the PCCL in the KDRG classification system exhibited low performance in explaining the variation in resource consumption within AADRGs. As the KDRG classification system is used for reimbursement under the new DRG-based prospective payment system (PPS) pilot project, with plans for expansion, there should be an overall review of the validity of the complexity and rationality of using the KDRG classification system.

Anticholinergic Use Among the Elderly With Alzheimer Disease in South Korea: A Population-based Study.

OBJECTIVES: To investigate the characteristics of anticholinergic use in the elderly with Alzheimer disease (AD) compared with those in the non-AD elderly. METHODS: Using the Korean National Health Insurance Service Elderly cohort database, 388,629 adults aged 70 years and older in 2012 were included. The use of strong anticholinergic agents (ACs) in 2012 was quantified by standardized prescribed doses. Univariate and multivariate logistic regression models were applied to examine the level of their heavy use (≥90 doses of the prescribed amount in 2012) in patients with AD and potential explanations of the heavy use. RESULTS: Antihistamines and antidepressants were the most prescribed strong ACs among non-AD and AD elderly, respectively. The heavy use of strong ACs was more prevalent in patients with AD than in non-AD elderly [odds ratio (95% confidence interval)=1.48 (1.41-1.56)]. When the morbidities associated with AD were adjusted for, odds ratio were reduced [0.91 (0.85-0.96)]. CONCLUSIONS: Heavy use of strong ACs was more prevalent in patients with AD than in non-AD elderly. Multiple ACs for treating multimorbidities in AD were mainly attributable to their heavy use. In patients with AD, the integrated management of medications for reducing the preventable heavy use of these drugs should be reinforced.

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.

Medical cost trends under national health insurance benefit extension in Republic of Korea.

This study examines whether the burden of medical expenses on households has gradually decreased since South Korea began implementing benefit expansion policies to strengthen health insurance coverage. Using Korea's Household Income & Expenditure Survey from 1995 to 2014, the annual average monthly household expenditures and the catastrophic health expenditure (CHE) indicator were analyzed. The latter is an indicator of household impoverishment resulting from out-of-pocket healthcare expenditures exceeding a defined threshold proportion of the household's income. Through descriptive and frequency data analyses and using P-values, the annual trends and differences in absolute values and share of CHE prevalence across households were measured. The study finds that the proportion of income spent on medical expenses increased from 2.47% (1995) to 4.94% (2014) on average. CHE also increased 3.6 times, 6.3 times, 9.8 times, and 11.1 times for assumed threshold sizes of 10%, 20%, 30%, and 40%, respectively. The lowest income group had the highest increase in CHE incidence. These results suggest that the benefit extension policy has lowered medical use thresholds and led to an increase in medical resource use. Therefore, the Ministries of Health and Welfare, and of Economy and Finance should collaborate to design policies for vulnerable groups.

Prognostic role of body mass index is different according to menopausal status and tumor subtype in breast cancer patients.

PURPOSE: Although controversial, obesity and underweight may have a negative impact on breast cancer outcome. However, the relationship between body mass index (BMI) and breast cancer outcomes according to tumor subtype and menopausal status remains unclear. METHODS: This study investigated the association between BMI and breast cancer outcome in stage I-III breast cancer patients. The relationships were further evaluated according to tumor subtype and menopausal status. RESULTS: A total of 5919 patients, 3475 (58.7%) hormone receptor (HR)(+) human epidermal growth factor receptor 2 (HER2)(-), 608 (10.3%) HR(+)HER2(+), 621 (10.5%) HR(-)HER2(+), and 1079 (18.2%) HR(-)HER2(-) were included. Underweight and obesity had a negative impact on relapse-free survival but did not affect overall survival. Importantly, the prognostic role of BMI was different according to tumor subtype and menopausal status. In HR(+)HER2(-) patients, underweight was associated with poor relapse-free survival and overall survival in pre-menopausal women. In contrast, obesity had negative impact on relapse-free survival and overall survival in HR(+)HER2(-) post-menopausal patients. Underweight may have a negative prognostic role in HR(+)HER2(+) patients. However, BMI did not impact the outcome of HR(-)HER2(+) and HR(-)HER2(-) patients. CONCLUSIONS: The impact of BMI on breast cancer outcome was dependent on tumor subtype and menopausal status. In HR(+)HER2(-) patients, underweight and obesity had a negative prognostic role in pre-menopausal and post-menopausal women, respectively. These findings in Asian population should be further evaluated and compared in Western population.

Increased risk of sleep disturbances in patients with rosacea: A nationwide population-based cohort study.

Rosacea is a chronic inflammatory skin disorder linked to various mental disorders, but little is known about the impact of rosacea on sleep disorders. The aim of this study is to confirm the association of rosacea with sleep disorders using a large administrative data set. This nationwide population-based retrospective cohort study enrolled 1129 individuals with rosacea and 11 017 age- and sex-matched controls without rosacea from the Korean National Health Insurance System database from 2002 to 2015. The prevalence of sleep disorder (7.8%) was significantly higher in patients with rosacea than in controls (5.81%; p < 0.001). Rosacea was associated with an increased risk of sleep disorder (adjusted odds ratio [aOR], 1.287 [95% confidence interval (CI), 1.022-1.623]). Among a variety of sleep disorders, patients with rosacea were likely to have an increased risk of insomnia (aOR, 1.318 [95% CI, 1.002-1.743]). In subgroup analysis, female patients with rosacea (aOR, 1.297 [95% CI, 1.010-1.722]) and those with rosacea and dyslipidemia (aOR, 1.417 [95% CI, 1.062-1.891]) were at a higher risk of having a sleep disorder. Rosacea is associated with an increased risk of having sleep disorders. The management of modifiable risk factors is important for managing sleep disorders in patients with rosacea.