Usability assessment of seven HIV self-test devices conducted with lay-users in Johannesburg, South Africa.

Introduction: The first 90 of the 90-90-90 initiative introduced by the World Health Organization(WHO) in 2015 requires 90% of people with HIV be aware of their status by 2020. In South Africa, conventional facility-based testing had reached 84.9% in 2018; innovative new methods, like HIV self-testing(HIVST) may close the testing gap. This study aimed to determine the usability of seven HIVST kits among untrained South Africans.

Methods: This cross-sectional study of 1400 adults in Johannesburg evaluated the usability of five blood fingerstick and two oral fluid HIVSTs, using WHO prequalification criteria, from June 2016 to June 2018. Participants were handed one kit, with no further information about the device or test procedure, and asked to perform the test in front of an observer. The observer used product-specific semi-structured questionnaires organized into a composite usability index(UI) using a HIVST process checklist, a contrived results interpretation and a post-test interview that expanded on participant experiences with the device and instructions-of-use(IFU). Participants were not tested themselves, but provided with contrived results to interpret.

Results: The average UI was 92.8%(84.2%-97.6%); the major difficulty was obtaining and transferring the specimen. Participants correctly interpreted 96.1% of the non-reactive/negative, 97.0% of the reactive/positive, 98.0% of the invalid and 79.9% of the weak positive results. Almost all participants(97.0%) stated they would visit a clinic or seek treatment for positive results; with negative results, half(50.6%) stated they should re-test in the next three months while one-third(36.1%) said they should condomize. Nearly all found the devices easy to use(96.6%), the IFUSs easy to understand(97.9%) and felt confident using the test unassisted(95.9%) but suggested improvements to packaging/IFUs to further increase usability; 19.9% preferred clinic-based testing to HIVST.

Conclusion: The UI and interpretation of results was high and in-line with previous usability studies, suggesting that these kits are appropriate for use in the general, untrained and unsupervised public.