Trends of new diagnosis and treatment initiation of hypertension during the COVID-19 pandemic in Korea.

The COVID-19 pandemic has broadly disrupted healthcare utilization, potentially affecting the diagnosis and treatment of hypertension. While most reports focus on countries with strict lockdowns, the impact on care in countries like South Korea that did not impose lockdowns remains unclear. This study aimed to investigate the changes in trends of new diagnosis and treatment initiation of hypertension in Korea during the pandemic. Using Korean nationwide claims data from 2015 to 2020, we identified new diagnosis and treatment initiation of hypertension. New diagnosis was defined as a claim for essential hypertension (International Classification of Diseases-10 code: I10), and treatment initiation was defined as a hypertension claim with antihypertensive prescription. Age-standardized rates were calculated using the 2020 insured population. Monthly trends in 2020 were compared with 2019 and with projected rates estimated using autoregressive integrated moving average (ARIMA) models based on pre-pandemic trends from 2015 to 2019. Analyses were conducted at the national and subnational levels. From 2015 to 2019, the rates of new diagnosis and treatment initiation of hypertension increased steadily, but both decreased in 2020. The most pronounced monthly decrease occurred in March 2020, with the largest regional declines observed in Daegu and Gyeongbuk. In the ARIMA model analysis, the observed rates in March 2020 were approximately 21% lower than expected rates for new diagnosis and 18% lower for treatment initiation. A substantial decline in new diagnosis and treatment initiation of hypertension was observed during the early phase of the COVID-19 pandemic in Korea.