A Lay-User Assessment of Hepatitis C Virus Self-Testing Device Usability and Interpretation in Johannesburg, South Africa.

Only 20% of people with hepatitis C virus (HCV) know their status. In low-income countries diagnosis is under 10%. Self-testing for HCV antibodies (HCVST) could expand the coverage of HCV testing services. Currently, there are no stringent regulatory authority (SRA) approved HCVSTs, therefore lay-user usability of three prototype kits was assessed. This was a cross-sectional observational study conducted with 171 (CareStart n = 60, Bioline n = 52, First Response n = 59) participants. Participants were given one of the three HCVST kits with only instructions for use (IFU) and asked to perform the test in front of a professional trained in rapid diagnostic tests (RDT). Usability indices were calculated based on the correctness of performing each step of the product-specific process followed by contrived results interpretation and a post-test interview. The usability index was 93.9% for CareStart, 90.7% for Bioline and 94.9% for First Response. Most errors were on incorrect handwashing, sample collection and transfer to the test device. An average of 93.1% of contrived results were correctly interpreted, with most errors related to interpreting invalid results. Most participants (n = 167) stated they would visit a clinic after a positive result. With negative results, nearly half (28/60 (46.7%)) stated they should condomize, while just over two-thirds of participants that used Bioline (35/52 (67.3%)) and First Response (38/59 (64.4%)) said they should re-test. Most participants (n = 162) found the devices easy to use. Participants liked that self-testing was fast, private and convenient, however there were some confusion with IFU steps and pictures, finger-pricking with the lancet, collecting blood after the finger-prick, and transferring the sample/buffer. Prototype HCVST kits exhibit high usability and result interpretation by lay-users, and should be considered for SRA approval.