Association and Variation Between the COVID-19 Pandemic and Health Care Quality in the Medicare Shared Savings Program: Insights From a Seven-Year Natural Experiment.

Potential changes in health care quality resulting from variation in pandemic severity since 2020 have received less attention. This study aims to assess the relationship between the pandemic and health care quality in Medicare Shared Savings Program (MSSP) accountable care organizations and identify possible heterogeneity in the relationship. The year-by-year difference-in-difference event study of MSSPs between 2016 and 2022 (N = 3390) indicated that 1 standard deviation increase in standardized cumulative COVID-19 incidence in 2020 was associated with a decrease in total quality score of 0.83 percentage points (95% CI: -0.21 to 1.44) after controlling for confounders. The reduction in quality score was mostly driven by ACOs with the highest COVID-19 incidence and in the Midwest. We found no evidence for a persisting decline in quality scores in 2021 to 2022. Public health efforts may need to carefully monitor quality performance and mitigate negative effects during future health crises. Continued investment in strengthening health care resilience remains crucial.