Background: Sedentary behavior is associated with increased cardiovascular disease (CVD) risk. We investigated this association of sedentary time and physical activity with increased 10-year CVD risk in Korean adults. Methods: This cross-sectional study used data from the Korea National Health and Nutrition Examination Survey (2014–2017). In total, 14,551 participants aged 30–74 years (6,323 men, 8,228 women) were analyzed. The usual length of sedentary time per day was categorized into three groups (<6, 6–<9, or ≥9 h/d), and physical activity (metabolic equivalents [METs]∙min/wk) was categorized into two groups (low, <600 METs∙min/wk; moderate/high, ≥600 METs∙min/wk). Logistic regression analysis was performed to assess the association between sedentary time and increased CVD risk (predicted 10-year risk ≥10%). Adjusted variables were age, sex, body mass index, marital status, employment, household income, alcohol use, family history of CVD, and comorbidity (hypertension, diabetes, and dyslipidemia). Results: The average sedentary time for the 14,551 participants was 7.49 h/d, with an average 10-year CVD risk of 9.58%. There was no significant association between sedentary time and increased 10-year CVD risk in the moderate/ high physical activity group. In the low physical activity group, sedentary time ≥9 h/d had a significant association with increased CVD risk (odds ratio [OR], 1.29; 95% confidence interval [CI], 1.04–1.62). However, when the sedentary time was <6 h/d, no significant associations were found (OR, 1.17; 95% CI, 0.92–1.49). Conclusion In the low physical activity group, reduction of sedentary time might be important for preventing increased CVD risk.

Background: Korea has gradually expanded the coverage of medical care services in its national health insurance system. On April 1, 2018, it implemented a policy that expanded the coverage for an ultrasonography in the upper abdomen. In this study, we aimed to investigate the effect of the policy on the utilization of the ultrasonography in the upper abdomen in tertiary care hospitals. Methods: Using the dataset of the Health Insurance Review and Assessment Service, we explored changes in the utilization of the ultrasonography in the upper abdomen in tertiary care hospitals from July 1, 2017 to November 30, 2018 through the difference-in-difference (DID) mixed-effects-model method. Facility factor, equipment factor and personnel factors, type of hospital, the total amount of medical care expenses, and geographic region were considered as control variables. Results: On average, the utilization of the ultrasonography in the upper abdomen increased by 228% after the coverage expansion policy. However, the results of DID mixed-effects-model method analysis showed that the utilization increased by 73%. As for the number of beds, the utilization was higher with a group of 844–930, 931–1,217, and 1,218 or greater compared with a group of 843 or fewer, while the utilization of the number of ultrasonic devices was lower with a group of 45–49 compared with a group of 44 or fewer. The utilization decreased with the number of interns and the number of nurse assistants. Besides, relative to Seoul, the utilization was lower in the other metro-cities and provinces. Conclusion The coverage expansion policy in the national health insurance system increased service utilization among people. Future research needs to investigate the degree to which such coverage expansion policy reduces the unmet medical care needs among the deprived in Korea.