SARS-CoV-2 testing behavior in symptomatic adults in a U.S. national cohort, 2020-2023: influence of exposure risk, susceptibility and healthcare access.

BACKGROUND: COVID-19 continues to circulate and cause illness, hospitalizations and death in the U.S, underscoring the importance of understanding SARS-CoV-2 testing behavior among symptomatic adults. Yet few studies have evaluated testing frequency in this population. We examined SARS-CoV-2 testing patterns, including at-home and laboratory tests, among adults with COVID-like symptoms from 2020 to 2023, and assessed the influence of exposure risk, susceptibility to COVID-19 complications, and barriers to healthcare access on frequency of testing when ill. METHODS: The CHASING COVID Cohort study comprises a diverse sample of U.S. adults, with data collected quarterly from March 2020 to December 2023. We categorized participants with COVID-like symptoms as 'frequent testers' if they tested ≥ 66% of the time when symptomatic, 'occasional testers' if they tested > 33% and < 66% of the time, and 'infrequent testers' if they tested ≤ 33% of the time. Informed by the Blumenshine Pandemic Disease Framework, we examined the impact of SARS-CoV-2 exposure risk, susceptibility to COVID-19 complications if infected, and barriers to healthcare access on testing frequency using crude and adjusted log-binomial regression models. RESULTS: A total of 3929 participants reported symptoms of COVID-like illness in at least two assessments. A quarter (25%) of participants were frequent testers, 47% were occasional testers, and 29% were infrequent testers. One-third (30%) had greater risk of SARS-CoV-2 exposure, 51% were susceptible to COVID-19 complications, 24% were uninsured, and 34% had no regular provider of care. Testing frequency was positively correlated with household income, educational attainment, COVID-19 vaccination, willingness to take antivirals, trust in public health agencies and healthcare providers for COVID-19 vaccine information. Those with more (versus less) exposure risk (aRR 1.14, 95% CI [1.01, 1.26]), COVID-19 susceptibility (aRR 1.17, 95% CI [1.05, 1.30]), no insurance (aRR 1.52, 95% CI [1.37, 1.70]), and no regular healthcare provider (aRR 1.32, 95% CI [1.19, 1.46]) were more likely to test infrequently. CONCLUSIONS: Individuals with the greatest risk of SARS-CoV-2 exposure, susceptibility to COVID-19 complications, and barriers to healthcare access were the least likely to test when ill. Public health initiatives should prioritize improving testing uptake among these populations.