Impact of COVID-19 infection rates on admissions for ambulatory care sensitive conditions: nationwide difference-in-difference design in Japan

OBJECTIVES: SARS-CoV-2 infection (COVID-19) has affected tertiary medical institutions and primary care. Admission for ambulatory care sensitive conditions (ACSCs) is an important indicator of primary care quality. However, no nationwide study, especially in Asia, has examined the association between admissions for ACSCs and local surges in COVID-19. This study aimed to examine how the number of admissions for ACSCs has changed in Japan between the areas with higher and lower rates of COVID-19 infection. DESIGN: This was a retrospective two-stage cross-sectional study. We employed a difference-in-difference design to compare the number of hospital admissions for ACSCs between the areas with higher and lower rates of COVID-19 infection in Japan. SETTING: The study used a nationwide database in Japan. PARTICIPANTS: All patients were aged 20 years and above and were admitted due to ACSCs during the study period between March and September 2019 (before the pandemic) and between March and September 2020 (during the pandemic). RESULTS: The total number of ACSC admissions was 464 560 (276 530 in 2019 and 188 030 in 2020). The change in the number of admissions for ACSCs per 100 000 was not statistically significant between the areas with higher and lower rates of COVID-19 infection: 7.50 (95% CI −87.02 to 102.01). In addition, in acute, chronic and preventable ACSCs, the number of admissions per 100 000 individuals did not change significantly. CONCLUSION: Although admissions for ACSCs decreased during the COVID-19 pandemic, there was no significant change between the areas with higher and lower rates of COVID-19 infection. This implies that the COVID-19 pandemic affected the areas with higher infection rates and the areas with lower rates.