Missing Race and Ethnicity Data among COVID-19 Cases in Massachusetts

Infectious disease surveillance frequently lacks complete information on race and ethnicity, making it difficult to identify health inequities. Greater awareness of this issue has occurred due to the COVID-19 pandemic, during which inequities in cases, hospitalizations, and deaths were reported but with evidence of substantial missing demographic details. Although the problem of missing race and ethnicity data in COVID-19 cases has been well documented, neither its spatiotemporal variation nor its particular drivers have been characterized. Using individual-level data on confirmed COVID-19 cases in Massachusetts from March 2020 to February 2021, we show how missing race and ethnicity data: (1) varied over time, appearing to increase sharply during two different periods of rapid case growth; (2) differed substantially between towns, indicating a nonrandom distribution; and (3) was associated significantly with several individual- and town-level characteristics in a mixed-effects regression model, suggesting a combination of personal and infrastructural drivers of missing data that persisted despite state and federal data-collection mandates. We discuss how a variety of factors may contribute to persistent missing data but could potentially be mitigated in future contexts.

Automated summary

Infectious disease surveillance often lacks complete information on race and ethnicity, hindering the identification of health disparities. The COVID-19 pandemic has brought greater attention to this issue, revealing significant missing demographic details in reported cases, hospitalizations, and deaths. This study analyzed individual-level data on confirmed COVID-19 cases in Massachusetts from March 2020 to February 2021 and found that missing race and ethnicity data varied over time, showed nonrandom distribution across towns, and were associated with various individual- and town-level characteristics.