Assessment of sociodemographic factors associated with time to self-reported COVID-19 infection among a large multi-center prospective cohort population in the southeastern United States

We aimed to investigate sociodemographic factors associated with self-reported COVID-19 infection. The study population was a prospective multicenter cohort of adult volunteers recruited from healthcare systems located in the mid-Atlantic and southern United States. Between April 2020 and October 2021, participants completed daily online questionnaires about symptoms, exposures, and risk behaviors related to COVID-19, including self-reports of positive SARS CoV-2 detection tests and COVID-19 vaccination. Analysis of time from study enrollment to self-reported COVID-19 infection used a time-varying mixed effects Cox-proportional hazards framework. Overall, 1,603 of 27,214 study participants (5.9%) reported a positive COVID-19 test during the study period. The adjusted hazard ratio demonstrated lower risk for women, those with a graduate level degree, and smokers. A higher risk was observed for healthcare workers, those aged 18-34, those in rural areas, those from households where a member attends school or interacts with the public, and those who visited a health provider in the last year. We identified subgroups within healthcare network populations defined by age, occupational exposure, and rural location reporting higher than average rates of COVID-19 infection for our surveillance population. These subgroups should be monitored closely in future epidemics of respiratory viral diseases.