Self-Reported Use of COVID-19 Immunologic Test Results to Inform Decisions About Daily Activities and COVID-19 Vaccination

ImportanceDespite widespread use of clinical diagnostic tests to assess prior exposure to SARS-CoV-2, limited evidence exists regarding how test results affect patient behaviors and decision-making. ObjectiveTo understand the rationale behind ordering diagnostic T-cell receptor (TCR) immunosequencing for assessment of prior SARS-CoV-2 infection and evaluate how test results affect patient behaviors, including day-to-day activities and decisions about vaccination. DesignMandatory demographic information and clinical characteristics were collected for all individuals ordering T-Detect COVID. Study participants completed a one-time survey that included additional questions about demographics and clinical characteristics, relevant interactions with healthcare providers, reasons for ordering diagnostic TCR immunosequencing, and the utility of test results. SettingUS participants ordering T-Detect COVID between February 2021 and March 2022. ParticipantsOf the 806 individuals who underwent diagnostic TCR immunosequencing, provided informed consent, and were sent the email survey, 718 completed the survey (response rate, 89.1%). At the time of receiving the test report, 25.5% of participants had been vaccinated against COVID-19, 29.7% reported a previous COVID-19 infection, and 25.6% were immunocompromised. Main Outcome(s) and Measure(s)Patient demographics and clinical characteristics were reported using descriptive statistics. Additional analyses explored trends in reported data over time and evaluated reasons for ordering diagnostic TCR immunosequencing and behaviors among participant subgroups (vaccinated or unvaccinated individuals and those with positive or negative test results). Logistic regression analysis evaluated factors that increased the likelihood of post-test vaccination. ResultsStudy participants ordered diagnostic TCR immunosequencing to understand their health status (55.0%) and to inform decision-making about daily activities (43.6%) and vaccination (38.3%). Most participants (92.1%) ordered diagnostic TCR immunosequencing for themselves without consulting their physician. Testing negative for prior SARS-CoV-2 infection was associated with increased likelihood of subsequent COVID-19 vaccination (31.0% vs 6.9%; median time to vaccination, 17.0 days vs 47.5 days), which was confirmed by logistic regression analysis. Conclusions and RelevanceThis report presents patient-reported clinical utility of a commercial COVID-19 assay based on an immune response readout. Our findings suggest that participants used diagnostic TCR immunosequencing results to inform decisions about daily activities and COVID-19 vaccination. Trial RegistrationNot applicable. KEY POINTSO_LIWe aimed to understand the factors driving immunologic testing for SARS-CoV-2 and characterize the actions and decisions spurred by test results. C_LIO_LIResults of this study suggest that individuals frequently ordered immunologic testing for themselves to understand their health status and to inform decision-making about daily activities and vaccination. C_LIO_LIAmong unvaccinated participants, testing negative for prior SARS-CoV-2 infection was associated with increased likelihood of undergoing vaccination and shorter time to vaccination. C_LIO_LIThis study provides the first real-world evidence of patient-perceived utility of a COVID-19 immunologic test for decision-making related to vaccination and lifestyle. C_LI