An increasing number of studies are using healthcare claims databases to assess healthcare intervention utilization patterns or outcomes in real-world clinical settings. However, methodological issues affecting study design or data analysis can make conducting and reporting these types of studies difficult. This review presents an overview of the types of information contained in claims data, describes some advantages and limitations of using claims data for research purposes, and outlines steps for utilizing the Korea Health Insurance Review and Assessment and National Health Insurance Service databases. The study also reviews epidemiological approaches utilizing healthcare claims databases (including cross-sectional, case-control, case-crossover, and cohort designs) with respect to protocol development, analysis, and reporting of results, and introduces relevant guidelines and checklists, including the Guidelines for Good Pharmacoepidemiology Practices, the Strengthening the Reporting of Observational Studies in Epidemiology checklist, and the Risk of Bias in Nonrandomized Studies of Interventions tool.

Ko YJ, et al. J Korean Med Sci. 2018 May;33(23):e163. https://doi.org/10.3346/jkms.2018.33.e163

The long-term outcome of first-line moderate-intensity statin with ezetimibe combination therapy for secondary prevention after percutaneous coronary intervention in patients with acute coronary syndrome (ACS) compared to high-intensity statin monotherapy remains elusive. The objective of this study was to compare the effectiveness of moderate-intensity statin and ezetimibe combination therapy with high-intensity statin monotherapy. We conducted a nationwide, population-based, retrospective, cohort study of patients with ACS from 2013 to 2019. The patients using combination therapy were matched (1:1) to those using monotherapy. The primary outcome was a composite of myocardial infarction, stroke and all-cause mortality. We estimated the hazard ratios (HR) and 95% confidence intervals (CIs) using the Cox proportional hazards regression. After propensity score matching, 10,723 pairs were selected. Men accounted for 70% of the patients and 37% aged > 70 years. The primary endpoint occurred in 1297 patients (12.1%) in the combination group and in 1426 patients (13.3%) in the monotherapy group, and decreased risk (HR 0.85, 95% CI 0.78–0.92, P < 0.001) in the combination group. Among the patients with ACS, moderate-intensity statin with ezetimibe combination therapy was associated with decreased risk of adverse cardiovascular outcomes compared with high-intensity statin monotherapy in a nationwide population-based study representing routine clinical practice.

There is increasing concern that the effects of the COVID-19 pandemic will result in excess suicides by increasing known risk factors, such as suicide attempts. However, evidence on the long-term impacts of COVID-19 on suicide attempts is lacking. We aimed to assess the short- and long-term effects of the COVID-19 pandemic on patients with suicide attempts in emergency departments (EDs) and to evaluate age- and sex-specific differences. We conducted nationwide cross-sectional study among patients with suicide attempts in the ED from 2016 to 2021. The trend test were used to determine whether study subjects were affected by changes in ED visits for suicide attempts. We estimated the average annual percentage change (APC) stratified by sex and age groups. The number of ED visits related to suicide attempts increased from 27,581 in 2016 to 37,719 in 2021. In particular, it decreased immediately after the COVID-19 pandemic but increased again in 2021. We identified that the average APC increased by 6.8 % overall, 1.6 % among males, and 10.8 % among females. Moreover, the APC of trend sharply increased in patients aged 10s and 20s. The in-hospital mortality was 3.6 % for females, compared to 9.5 % for males, which showed sex differences. This study was limited to confirming causal relationship based on a descriptive study. The incidence of suicide attempts in ED has increased in Korea. In particular, there was a sharp increase among women, adolescents and young adults. Patient-tailored treatment and preventive medical system for suicide attempts is important.

Choi A, et al. J Lipid Atheroscler. 2025 Jan;14(1):30-39. https://doi.org/10.12997/jla.2025.14.1.30