Hwa Young Choi

A nationwide seroepidemiology of hepatitis C virus infection in South Korea

The aim of this study was to reveal nationwide seroprevalence of HCV infection in South Korea by a large‐scale survey.

Incidence, prevalence and complications of Budd-Chiari syndrome in South Korea: a nationwide, population-based study.

The population‐based epidemiology of Budd–Chiari syndrome (BCS), a rare disease of hepatic venous outflow obstruction, is largely unknown. This study aimed to elucidate the nationwide population‐based incidence, prevalence, complications, case fatalities and direct medical cost of BCS in South Korea from 2009 to 2013.

Comparison and analysis of the prevalence of hepatitis C virus infection by region in the Republic of Korea during 2005-2012

Background/Aims This study compared the prevalence of hepatitis C virus (HCV) infection in the Republic of Korea and estimated the high-risk regions and towns. Methods National Health Insurance Service data for 8 years from 2005 to 2012 were used. The subjects of the study had visited medical facilities and been diagnosed with or received treatment for acute or chronic HCV as a primary or secondary disease according to ICD-10 codes of B17.1 or B18.2, respectively. Any patient who received treatment for the same disease multiple times during 1 year was counted as one patient in that year. To correct for the effect of the age structure of the population by year and region, the age-adjusted prevalence was calculated using the direct method based on the registered population in 2010. Results The overall prevalence of HCV infection among Korean adults (>20 years old) increased from 0.14% in 2005 to 0.18% in 2012. The sex-, age-, and region-adjusted prevalence in 2012 was 0.18%. The prevalence was highest in Busan, Jeonnam, and Gyeongnam, and there were towns with noticeably higher prevalences within these regions: Jindo (0.97%) in Jeonnam, Namhae (0.90%) in Gyeongnam, and Seo-gu (0.86%) in Busan. Conclusions The prevalence of HCV infection differs by regions as well as towns in the Republic of Korea, and is highest in Busan, Jeonnam, and Gyeongnam. The reasons for the high prevalence in these specific regions should be identified, since this could help prevent HCV infections in the future. In addition, active surveillance and treatment policies should be introduced to stop any further spread of infection in these high-prevalence regions.

Prevalence of fungal infections using National Health Insurance data from 2009-2013, South Korea.

OBJECTIVES The symptoms of fungal infections vary from minor to severe. According to recent reports, fungal infection prevalence is increasing due to increases in the aging population and in patients with compromised immune systems. However, the total prevalence of fungal infections in South Korea is unknown. We investigated the recent 5-year prevalence of each type of fungal infection in South Korea across age, sex, and regional groups. METHODS Nationwide data from the National Health Insurance of South Korea were used. The target population included patients who had received treatment for a fungal infection that was listed as the main disease. For each patient, multiple treatments were counted as one case per year in the data analysis. RESULTS The annual prevalence of all-type mycoses increased from 6.9% in 2009 to 7.4% in 2013. Among the specific groups, the prevalence of dermatophytosis was highest (5.2%), followed by that of opportunistic mycoses (1.7%) and superficial mycoses (0.2%). The prevalence of subcutaneous mycoses and generalized mycoses was very low (8 cases per 100,000 persons and 3 cases per 1 million persons, respectively). CONCLUSIONS Every year, approximately 7.1% of the Korean population receives treatment for fungal diseases. Cases of opportunistic mycoses are assumed to increase each year. Therefore, further research is needed to understand and monitor the prevalence of mycoses to establish management policies to reduce the burden of fungal diseases.

Current status of hepatitis C virus infection and countermeasures in South Korea

Hepatitis C virus (HCV) infection is a major cause of liver cirrhosis, hepatocellular carcinoma, and liver-related mortality. The new antiviral drugs against HCV, direct acting antivirals, result in >90% cure rate. This review aimed to summarize the current prevalence, clinical characteristics, outcomes, and treatment response associated with HCV infection, and countermeasures for optimal HCV control in South Korea. Based on a literature review, the current anti-HCV prevalence in the Korean population is 0.6 to 0.8%, with increasing prevalence according to age. The major HCV genotypes in Korean patients were genotype 1b and genotype 2. Successful antiviral treatment leads to significantly reduced liver related complications and mortality. However, only about one third of the individuals with HCV infection seem to be managed under the current national health insurance system, suggesting a remarkable rate of underdiagnoses and subsequent loss of opportunity to cure. A recent study in South Korea showed that targeted population screening for HCV infection is cost-effective. To prevent recently developed clusters of HCV infection in some clinics, mandatory surveillance rather than sentinel surveillance for HCV infection is required and governmental countermeasures to prevent reuse of syringes or other medical devises, and public education should be maintained. Moreover, one-time screening for a targeted population should be considered and a cost-effectiveness study supporting an optimal screening strategy is warranted.

Population-based prevalence, incidence, and disease burden of autoimmune hepatitis in South Korea

Background and aim Little is known about population-based epidemiology and disease burden of autoimmune hepatitis (AIH). The aim of this study was to investigate the prevalence, incidence, comorbidity and direct medical cost of AIH in South Korea. Methods The data was from the nationwide, population-based National Health Insurance Service claims database and the Rare Intractable Disease registration program. Age and gender-specific prevalence rates were calculated, and data on comorbidity, diagnostic tests, prescribed drugs, and medical costs were retrieved for patients registered under the disease code K75.4 (AIH) from 2009 to 2013. Results A total of 4,085 patients with AIH were identified between 2009 and 2013 with a female-to-male ratio of 6.4. The age-adjusted prevalence rate was 4.82/100,000 persons and gender adjusted prevalence rates were 8.35 in females and 1.30 in males. The age-adjusted calculated incidence rate was 1.07/100,000 persons (gender-adjusted 1.83 in females and 0.31 in males). Ascites, variceal bleeding, and hepatocellular carcinoma were found in 1.4%, 1.3%, and 2.2% of the patients, respectively. Forty-six patients (1.1%) underwent liver transplantation during the study period. Case-fatality was 2.18%. Corticosteroid and azathioprine were prescribed in 44.1% and 38.0% of prevalent patients with AIH in 2013, respectively. The nationwide total direct medical cost was less than 4.0 million USD, and the average cost for each patient was 1,174 USD in 2013. Conclusion This is the first report on the nationwide epidemiology of AIH in Korea, and it showed a lower prevalence than that of Western countries with considerable disease burden.

Risk Factors for Hepatitis C Virus (HCV) Infection in Areas with a High Prevalence of HCV in the Republic of Korea in 2013

Background/Aims The prevalence of hepatitis C virus (HCV) infection in Busan, Gyeongnam, and Jeonnam Provinces in Korea is more than twice the national average. This study aimed to examine whether demographic and lifestyle characteristics are associated with HCV infection in these areas. Methods A case control study was performed at three study hospitals. HCV cases were matched with two controls for sex and age. Patient controls were selected from non-HCV patients at the same hospital. Healthy controls were subjects participating in medical checkups. Conditional logistic regression models were used. Results A total of 234 matched-case and patient- and healthy-control pairs were analyzed. The significant risk factors for both controls were sharing razors (adjusted odds ratio [aOR], 2.39 and 3.29, respectively) and having more than four lifetime sexual partners (aOR, 2.15 and 6.89, respectively). Contact dockworkers (aOR, 1.91) and tattoos (aOR, 2.20) were significant risk factors for the patient controls. Transfusion (aOR, 5.38), a bloody operation (aOR, 5.02), acupuncture (aOR, 2.08), and piercing (aOR, 5.95) were significant risk factors for the healthy controls. Needle stick injuries and intravenous drug abuse were significant in the univariate analysis. Conclusions More education concerning the dangers of sharing razors, tattoos and piercings is required to prevent HCV infection. More attention should be paid to needle stick injuries in hospitals and the community.

Healthcare Costs for Chronic Hepatitis C in South Korea from 2009 to 2013: An Analysis of the National Health Insurance Claims’ Data

Background/Aims The introduction of direct-acting antivirals (DAA) in 2013 revolutionized hepatitis C virus (HCV) treatment, offering a cure rate >90%. However, this therapy is expensive, and estimations of the number of chronic HCV-infected (CHC) patients and their treatment costs pre-2013 are therefore essential for creating policies and expanding drug access. Herein, we aimed to investigate the number of HCV-related liver disease patients, their healthcare utilization, their annual direct medical costs, and the interferon-based antiviral treatment rates and costs from 2009 to 2013 in South Korea. Methods The National Health Insurance database was reviewed, and patients diagnosed with CHC from 2009 to 2013 were extracted. Data regarding detailed healthcare utilization, prescribed drugs, and direct medical costs were obtained. For annual direct healthcare cost calculations, a prevalence-based approach was used. Results Overall, 181,768 CHC patients were identified. In 2013, the annual per-patient costs for chronic hepatitis, liver cirrhosis, hepatocellular carcinoma, and the first year post-liver transplant were 895, 1,873, 6,945, and 67,359 United States dollars, respectively. Interferon-based antiviral therapeutics were prescribed to 25,223 patients (13.9%). Conclusions Healthcare costs have increased remarkably with increasing liver disease severity. Thus, efforts to stop disease progression are needed. Moreover, the low rate of interferon-based therapy indicates an unmet need for DAA.

Health behavior associated with liver enzymes among obese Korean adolescents, 2009–2014

Aims Obesity is major risk factor for liver health. This study aimed to clarify whether specific health behaviors were associated with liver function in obese adolescents in Korea. Methods Based on national school health examination data from 2009 to 2014, 25,142 obese or overweight students were examined for aspartate transaminase and alanine transaminase levels, and health behaviors. Multiple logistic regression was used to calculate the odds ratio for liver enzyme elevation. Results Subjects who thought of themselves as “very fat” had a 1.6 times higher odds ratio for liver enzyme elevations than those who thought of themselves as “normal.” Those who consumed fast food 3 to 5 times weekly had 1.3 times higher odds ratio (OR = 1.27, 95% confidence interval = 1.05–1.54) for the elevation of ALT than those who did not consume fast food. Those who took sugar-sweetened beverage 3 to 5 times weekly had 1.2 times higher odds ratio (OR = 1.24, 95% confidence interval = 1.07–1.42) for the elevation of ALT than those who did not take it. Those who played computer game more than 2 hours a day showed 1.1 times higher odds ratio (OR = 1.10, 95% confidence interval = 1.01–1.21) for the elevation of ALT than those who did not. Conclusions Specific food item and its frequency of consumption were identified for the positive and negative association with the elevation of liver enzymes. Self-image of body shape, sleeping time and need of help for alcohol or smoking problems also showed substantial association with the elevation.

Cost-effectiveness and health-related outcomes of screening for hepatitis C in Korean population

In the era of direct‐acting antivirals (DAA), active screening for hidden hepatitis C virus (HCV) infection is important for HCV elimination. This study estimated the cost‐effectiveness and health‐related outcomes of HCV screening and DAA treatment of a targeted population in Korea, where anti‐HCV prevalence was 0.6% in 2015.