JMIR Publications

ABSTRACT

Background:

Throughout the COVID-19 pandemic, regular population testing for severe acute respiratory syndrome coronavirus disease 19 (SARS-CoV-2) was crucial for disease monitoring and management. Initially, reverse-transcription polymerase chain reaction (RT-PCR) tests were primarily used for identifying new cases, but their high cost and delayed results, combined with laboratory capacity and supply chain limitations, led to the adoption of antigen-detection rapid diagnostic tests (Ag-RDT) at point of care locations. On August 11, 2022, the US Food and Drug Administration (FDA) issued a safety communication for serial Ag-RDT testing to reduce the risk of false negative results from singular testing and combat disease spread, followed by a revision letter on November 1, 2022, to manufacturers to update their authorized product labeling.

Objective:

This study evaluates adherence to serial testing using data from the CDC Increasing Community Access to Testing, Treatment, and Response (ICATT) program.

Methods:

This national, retrospective cohort study analyzed ICATT program line-level testing records from August 12, 2022, to January 14, 2025. Patients were included if they had at least one Ag-RDT test. Adherence was determined based on whether patients followed FDA guidance after a negative test. Multivariable logistic regression models were used to identify demographic features associated with adherence, with an expanded model to identify the impact of additional clinical variables. Rates of testing positive after an initial negative Ag-RDT test were also calculated for ICATT pharmacy testing.

Results:

There were 2,189,464 patients included in the second test adherence analysis and 6,813 included in the third test adherence analysis. Less than 1% of patients were adherent with the instructions to use a second Ag-RDT test, with 98.4% non-adherent because they did not have a second test. Patients were more likely to be second-test-adherent if they were Asian or Black and less likely to be adherent if they were children. When adjusting for additional clinical variables, recent COVID-19 contact was associated with higher odds of adherence, while recent COVID-19 infection was associated with lower odds of adherence. Of those initially testing negative with an Ag-RDT test, 24.9% tested positive on their second test, and 57.4% of these episodes were adherent. For asymptomatic patients, 4.2% tested positive on their third test after testing negative on their first two, with 60% adherence.

Conclusions:

This study is the first to evaluate adherence to the FDA instructions to perform serial Ag-RDT tests. Overall, adherence was low among patients seeking testing at community sites. Recent COVID-19 exposure was associated with the highest odds of serial testing adherence. These insights can inform targeted public health strategies to improve adherence and reduce the risk of false negatives from Ag-RDT tests in future pandemics.