Evaluating the effect of the COVID-19 pandemic on hypertension and diabetes care in South Korea: an interrupted time series analysis

BACKGROUND: Access to healthcare services is important, especially for patients with chronic diseases. We evaluated the effect of the COVID-19 pandemic on outpatient visits and medication for patients with hypertension and diabetes in South Korea. METHODS: Nationwide claims data were extracted for patients with hypertension and diabetes from January 2019 to July 2020. We used an interrupted time series (ITS) analysis to evaluate the pandemic’s impact on outpatient care using the number of outpatient visits and days of medication supplied per visit. We identified the change in the continuity of care in medication, a consequence of the change in outpatient care, using the Medication Possession Ratio (MPR). RESULTS: The number of outpatient visits for diabetes significantly declined in February 2020, when community transmission began. However, when high-intensity social distancing was relaxed in April 2020, outpatient visits for hypertension and diabetes rebounded significantly. Moreover, when the outpatient visits declined, the number of days of medication supplied per visit increased. Consequently, the average MPRs significantly increased compared to 2019, increasing the ratio of patients with appropriate medication supply (MPR ≥ 0.8). CONCLUSIONS: Outpatient visits decreased immediately when COVID-19 spread to local communities. However, the number of days of medication supplied per visit increased to compensate for the longer intervals between visits. Rather, the change in the continuity of care in medication improved; thus, the temporary decrease in outpatient visits might have had a limited negative impact on health outcomes. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-023-16430-z.