The Epidemiology of Diversity: COVID-19 Case Rate Patterns in California

California’s diverse population provides a natural laboratory for understanding how diseases and conditions interact within different racial/ethnic groups. This report seeks to illustrate the differential effects of the COVID-19 pandemic in the state’s “majority-minority” population and to discuss the resulting implications for public health. Laboratory-confirmed COVID-19 cases in California (disaggregated by race/ethnicity into mutually exclusive groups) were integrated with their respective population values to create case rates per 100,000 population, categorized by age group and race/ethnicity. The case rates within each non-White population, in almost every age group, were higher than the White Non-Hispanic population, ranging from one-and-a-half to nearly six times as high. Public health prevention measures such as sheltering-at-home rely on standard assumptions and models. The disparity in case rates found here suggests that alternative narratives such as the epidemiology of diversity may inform additional policies or measures.