The authors were interested in the acceptability and usability of home-based self-testing with lateral flow immunoassays (LFIA) for SARS-CoV-2 antibodies. They conducted pilot testing with 315 volunteers. This then informed the design of a nationally representative survey of adults in England using two LFIAs (LFIA1 and LFIA2), which were sent to 10,600 and 3,800 participants, respectively. The pilot testing indicated high levels of acceptability but highlighted limitations with the usability of the kits. Most people completed the test, however there were difficulties with the lancet and pipette, plus more guidance was needed on interpreting the results. In the national study, 99.3% of 8754 LFIA1 and 98.4% of 2957 LFIA2 respondents attempted the test, and 97.5% and 97.8% of respondents completed it. Most found that the instructions were easy to understand but there were some difficulties using the pipette (LFIA1 17.7%) and applying the blood drop to the cassette (LFIA2 31.3%). Most respondents obtained a valid result (LFIA1 91.5%, LFIA2 94.4%). Overall there was substantial concordance between participant and clinician interpreted results. Therefore public involvement with home self-testing with LFIAs can be used for seroprevalence surveys.
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