Incidence and prevalence of seropositive rheumatoid arthritis among Korean women of childbearing age: a nationwide population-based study

Background/Aims@#Women with rheumatoid arthritis (RA) are often diagnosed with the disease during their reproductive years; however, its incidence and prevalence among women of childbearing age have not been studied. The objective of this study was to estimate the incidence and prevalence of seropositive rheumatoid arthritis (SPRA) among Korean women of childbearing age. @*Methods@#Women aged 20 to 44 years with SPRA were identified from National Health Insurance Service-National Health Information Database (2009 to 2016). SPRA was defined by International Classification of Diseases, 10th revision code, M05. Incidence and prevalence were calculated per 100,000 person-years and stratified by year and age. @*Results@#The average incidence and prevalence of SPRA from 2011 to 2016 among women of childbearing age was 24.1/100,000 person-years (95% confidence interval [CI], 23.7 to 24.5) and 105.2/100,000 person-years (95% CI, 100.9 to 109.5), respectively. The incidence increased annually from 21.0/100,000 person-years (95% CI, 20.1 to 21.9) in 2009 to 28.4 person-years (95% CI, 27.3 to 29.5) in 2016. Similarly, the prevalence increased annually from 95.7/100,000 person-years (95% CI, 93.7 to 97.6) in 2009 to 111.0 person-years (95% CI, 108.9 to 113.2) in 2015, with a slight decrease in 2016 (110.4 person-years; 95% CI, 108.2 to 112.6). The incidence and prevalence of SPRA increased with advancing age. The peak age for both incidence and prevalence of SPRA among women of childbearing age was 40 to 44 years. @*Conclusions@#The risk of SPRA is high in women during their childbearing years; this population bears a significant disease burden. This calls for special attention to this particular population group to reduce the risk and burden of this disease.

Is Central Serous Chorioretinopathy a Risk Factor for NeurocardiovascularDisease Development?: 10-year Nationwide Population-based Study

Purpose@#We evaluated the risk of neurocardiovascular disease development after central serous chorioretinopathy (CSC). @*Methods@#We collected data from the Korean National Health Insurance Research Database (which contains information on1,025,340 [2.2%] random subjects selected from all Korea residents in 2002). Patients diagnosed with CSC, stroke, or ischemicheart disease (IHD) from 2002 to 2005 were excluded. The CSC group featured patients initially diagnosed with CSC fromJanuary 2006 to December 2010. The comparison group included randomly selected patients (five per CSC patient) matched toCSC patients by age, sex, residential area, and household income. @*Results@#Stroke developed in 4.41% of the CSC group and 4.11% of the comparison group. IHD developed in 7.93% of the CSCgroup and 7.27% of the comparison group. CSC was not significantly associated with an increased risk of stroke (hazard ratio[HR], 0.964; 95% confidence interval [CI], 0.65-1.424; p = 0.8532) or IHD (HR, 0.942; 95% CI, 0.694-1.279; p = 0.7018) after adjustingfor demographic characteristics and comorbidities. Subgroup analyses by age group and stroke subtype revealed no significantassociations with CSC or IHD status. @*Conclusions@#CSC was not associated with stroke or IHD development in patients of any age after adjusting for potential confounders.Further studies are needed to confirm a relationship between CSC and development of systemic cardiovascular disease.

Trends of Gout Prevalence in South Korea Based on Medical Utilization: A National Health Insurance Service Database (2002∼2015)

Objective@#. Although gout is the most common form of inflammatory arthritis, data on gout prevalence and management are sparse, especially in Korean populations. This study reevaluated the most recent prevalence and incidence of gout values in Korean people to update the findings from our previous study in 2011. @*Methods@#. We used the National Health Insurance Service-National Health Information Database (NHIS-NHID) to identify patients diagnosed with gout in South Korea during 2002∼2015. We selected patients with gout as principal diagnosis or 1st∼4th additional diagnosis. @*Results@#. The prevalence of gout increased 5.17-fold, from 0.39% in 2002 to 2.01% in 2015. This increase occurred in all age groups, but was stronger in those aged 80 years or older, with a 13.1-fold increase from 2002 to 2015. The prevalence of gout increased in all regions of South Korea. The prevalence of the disease was also related to income levels: in 2015, medical insurance subscribers with the highest income were twice more likely to have gout than those in the lowest income bracket. By contrast, the prevalence of gout in medical benefit recipients was 5.58- and 5.25-times higher than that of the general population and of those in the highest income bracket, respectively. @*Conclusion@#. The prevalence of gout has increased rapidly, although the degree of increase varied according to sex, age, region, and income group. This study sheds some light on the current prevalence of gout among national insurance subscribers in Korea, and will help educate patients and medical staff on the management of gout.

Is Pediatric Otitis Media Correlated with an Increased Risk of Bronchial Asthma?: An II-Year Nationwide Population-Based Study / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Pediatric otitis media is closely related to upper respiratory illness and is one of the most common causes of hospital visiting and antibiotic prescription. Although there are many studies of asthma with other upper respiratory tract infections, few studies have investigated the relationship between asthma and otitis media. This study estimated whether pediatric otitis media is associated with the risk of asthma using the Korean National Health Insurance Service National Sample Cohort (NHIS-NSC 2002-2013) data. SUBJECTS AND METHOD: In using the NHIS-NSC 2002-2013 data, children diagnosed as otitis media or bronchial asthma in 2002 were excluded from children from 1 to 8 years old in 2003. The patients who were diagnosed and treated as otitis media (n=8506) and the comparison group (n=65886) were enrolled in 2003. During a 10-year follow-up period until December 2013, the incidence of asthma between two groups was analyzed and the result was adjusted for the impact of comorbidities such as atopic dermatitis, allergic rhinitis with multivariate linear regression analyses. RESULTS: In 2003, 20.88% of first-year-old children were treated with otitis media. The prevalence of otitis media was maintained at 15% until age 4 and decreased rapidly after 5 years of age. Asthma incidence was reported higher in patients with otitis media compared to the comparison group, with an adjusted odds ratio of 1.196 [95% confidence interval (CI) 1.127-1.269] followed by patients with atopic dermatitis [hazard ratio (HR) 1.261, 95% CI 1.196-1.33], allergic rhinitis (HR 1.473, 95% CI 1.409-1.54). CONCLUSION: Pediatric otitis media appeared to be associated with an increased risk of developing bronchial asthma after adjusting for other risk factors.

The Prevalence and Incidence of Parkinson's Disease in South Korea: A 10-Year Nationwide Population: Based Study

BACKGROUND: The prevalence and incidence of Parkinson's disease (PD) are important for supporting the better comprehension of disease aspects and helping public health planning. Our aim is to evaluate the prevalence and incidence in South Korea between 2004 and 2013. METHODS: This retrospective, nationwide, longitudinal population-based study used National Health Insurance Service-National Sample Cohort Database to define patients with PD from 2004 to 2013 based on having Korean Classification of Diseases code G20, which were assigned by neurologists, and being prescribed PD medication. Annual prevalence and incidence were calculated. RESULTS: The prevalence of PD per 100,000 of population was 41.4 in 2004 and 142.5 in 2013, and there was 13.2% yearly increase over the 10 years. However, the incidence of PD per 100,000 of population increased steadily from 20.2 in 2004 to 53.1 in 2013. The prevalence and incidence were higher in women than in men. CONCLUSIONS: Our data show that there was an increasing trend in the prevalence and incidence of PD from 2004 to 2013, particularly in 70 years and older.

Changes in Allergen Sensitization Over The Last 30 Years in Korea Respiratory Allergic Patients: A Single-Center

PURPOSE: Determining the culprit allergen is important for the diagnosis and management of allergic diseases. The skin prick test (SPT) has been widely used to identify culprit allergens. Skin reactivity to allergens has changed due to changes in lifestyle and outdoor environments. Therefore, the aim of the present paper was to examine changes in allergen sensitization in Korea. METHODS: We enrolled 1,135 patients with respiratory allergic diseases who were diagnosed at Severance Hospital from January 2010 to December 2011. SPTs were performed with inhalant allergens, and were compared to our previous studies of the SPTs in the 1980s and the 1990s. RESULTS: In the 2010s, the SPT positive rate of allergic rhinitis or allergic conjunctivitis was higher than asthma without allergic rhinitis or allergic conjunctivitis. The SPT positive rate was decreased by increments of age (P value 14.4%), birch (7.1%->13.6%), alder (6.3%->13.4%) and pine (2.9%->14.3%) was significantly increased in the 2010s compared with the 1990s, respectively. Current skin reactivity to grass pollens (13.9%) and weed pollens (27.0%) has significantly decreased since the 1990s (20.3%, 40.9%, respectively). Skin reactivity to house dust mites showed no difference between the 1990s (55.2%) and the 2010s (55.6%). Skin reactivity to dog (27.3%->20.7%) and cockroach (25.3%->12.3%) have significantly decreased in the 2010s in comparison with the 1990s. CONCLUSIONS: In light of the above results, we revealed the changes in skin reactivity to inhalant allergens that have occurred in Korean allergic patients over the past three decades. Since outdoor environmental factors such as the amount of pollen, global warming and plant distribution causes the changes in skin reactivity, further study and continuous close observation will be needed.

An Epidemiological Analysis of Hepatitis A Virus Serologic Markers during the Recent Four Years in Korea / 대한진단검사의학회지

BACKGROUND: To establish effective preventive measures for hepatitis A virus (HAV) infection, a nationwide epidemiologic study on seroprevalence of anti-HAV and the disease prevalence is needed. The aim of this study was to analyze the recent sero-epidemiological changes of hepatitis A markers in Korea. METHODS: The results of 11,068 anti-HAV total and 32,360 anti-HAV IgM tests by electro-chemiluminescence immunoassay (ECLIA) that had been requested in recent four years (2005-2008) to a reference medical laboratory from 1,699 institutions nationwide were retrospectively analyzed according to the distribution of year, sex, and age groups. RESULTS: The overall positive rate of anti-HAV total was 62.8%. The overall positive rate of anti-HAV IgM was 11.0%, showing a significantly increasing trend by year: 7.7%, 10.9%, 8.9%, and 14.3% in 2005, 2006, 2007, and 2008, respectively (P or =21 yr. Conclusion: In accordance with a decreasing sero-positivity of anti-HAV total, the prevalence of acute hepatitis A virus infection has been considerably increased during the recent four years in the age groups of > or =21 yr. The results of this study could be used effectively as a basic data for establishing effective preventive measures for hepatitis A including vaccination in these susceptible age groups.

A Comparative Study on Medical Education Systems in Korea, China and Japan / 한국의학교육

PURPOSE: The present study examined the possibility of standardization of medical education in three Asian countries-Korea, China, and Japan, by comparing their medical education and licensing systems. METHODS: As the criterion for comparison, we divided medical education system into three stages- basic medical education, graduate medical education, and continuing medical education. In addition, we analyzed the history and social and cultural backgrounds of medical education in each country. Recent changes were also examined. RESULTS: While little difference was found in the medical curriculums and courses between Korea and Japan, China's differed significantly from these two countries. But all three countries do attempt to keep up with international standards. CONCLUSION: To improve the quality of medical education in Korea, China, and Japan, these three countries need a plan to standardize medical education compatible with international standards but one that differs from western medical education by incorporating traditional medicine.

Item Analysis of Clinical Performance Examination Using Item Response Theory and Classical Test Theory / 한국의학교육

PURPOSE: The objectives of this study were: 1) to analyze Clinical Performance Examination(CPX) items using item response theory(IRT) and classical test theory(CTT) and 2) to discuss how to apply and interpret these results in order to improve the quality of CPX items. In addition, we intended to explore statistical procedures in order to merge examination data from several different medical schools. METHODS: The subject of the study was the 2005 CPX examination data from 10 medical schools located in Seoul and the Kyunggi province. For merging data from ten different medical schools, Levene's test for homogeneity of variances was used. Homogeneous group selection was conducted based on ANOVA or Kruskal-Wallis' test and Tukey's multiple comparisons appropriately. The generalized partial credit model was applied to analyze polytomous items and the 2-parameter logistic model was used to analyze dichotomous items. RESULTS: Data from 8 medical schools were incorporated into the analysis. The result of the discrimination index by IRT was different from that of CTT in both polytomous and dichotomous items. Discrimination index from IRT tended to be lower than that of CTT. Difficulty index of dichotomous items of two models was correlated well with each other. However, for polytomous items, IRT model provided more information than CCT. CONCLUSION: We discovered that the CPX items were mostly easy in terms of difficulty index, and the result from IRT and CCT model did not correlated well in the discrimination index. IRT may provide more detailed information for polytomous items, but the checklist and criteria of scoring system should be cautiously reviewed.