Racial and Ethnic Differences in COVID-19 Disease Severity Among US Adults in Health Systems Participating in PCORnet®: May 2020-October 2022.

This study analyzed COVID-19 disease severity distributions among different age, racial, and ethnic groups for pre-Omicron and Omicron variant periods from May 2020 to October 2022. Disease severity categories were defined by ICD-10-CM diagnostic codes recorded in the electronic health record in the 7 days preceding and 13 days following the SARS-CoV-2 positive laboratory record (index date) and were grouped into 4 mutually exclusive categories: severe complications, high, moderate, and low disease severity. Low severity was defined as the absence of codes for any of the other categories. Among 1,613,706 included patients, there was a lower prevalence of disease severity during the Omicron variant period across all race and ethnicity groups (P<0.001) compared with the pre-Omicron variant period; however, the Omicron period had a higher prevalence of severe complications (P<0.05). Relative to White patients with high disease severity, Black patients and patients of other races had 37.1% and 52.4% (Pt<0.0001) greater risk of having high disease severity, respectively, in the pre-Omicron period, but high disease severity was similar across racial groups during the Omicron period. During pre-Omicron, mean monthly relative differences among Hispanic patients with high disease severity and severe complications compared with non-Hispanic patients were -5.17% and -39.4%, respectively, which shifted to 24.4% and 44.1% in the Omicron period (Pt<0.0001). These findings provide valuable insight into patterns of COVID-19 disease severity, especially for marginalized populations, and highlight the need for targeted public health strategies as variant-specific trends evolve over time.