Objective To identify risk factors associated with severe COVID-19 infection in a defined, Midwestern, U.S. population overall and within different age groups. Patients and Methods We used the Rochester Epidemiology Project research infrastructure to identify persons residing in a defined 27-county Midwestern region who had a positive PCR test for COVID-19 between 3/1/2020 and 09/30/2020 (N=9,928). Age, sex, race, ethnicity, body mass index, smoking status, and 44 chronic disease categories were considered as possible risk factors for severe infection. Severe infection was defined as hospitalization or death due to COVID-19. Associations between risk factors and severe infection were estimated using Cox proportional hazard models overall and within 3 age groups (0-44, 45-64, and 65+ years). Results Overall, 474 (4.8%) persons developed severe COVID-19 infection. Older age, male sex, non-white race, Hispanic ethnicity, obesity, and a higher number of chronic conditions were associated with increased risk of severe infection. After adjustment, 36 chronic disease categories were significantly associated with severe infection. The risk of severe infection varied significantly across age groups. In particular, persons 0-44 years with cancer, chronic neurologic disorders, hematologic disorders, ischemic heart disease, and other endocrine disorders had a greater than 3-fold increased risk of severe infection compared to persons of the same age without those conditions. Associations were attenuated in older age groups. Conclusion Older persons are more likely to experience severe infections; however, severe cases occur in younger persons as well. Our data provide insight regarding younger persons at especially high risk of severe COVID-19 infection.
Factors Associated With Severe COVID-19 Infection Among Persons of Different Ages Living in a Defined Midwestern US Population