Power calculation and analysis plan
POC HIV VL
REGRESSION
Using data from prior studies, we observed an LTC rate of 22% for the JHHED patients who are living with HIV but not in care or who are HIV-negative and PrEP-eligible, and an LTC rate of 50% for PrEP-eligible patients attending STI services or recruited via social media, resulting in an overall aggregate LTC rate of 32.5% (with 63% patient enrollment in the JHHED and 37% in the STI clinics/participants recruited via social media). To detect an increase of LTC rate from 32.5 to 52.5% within the intervention arm, with 80% power and a two-sided significance level of 0.05, a total of 95 participants are required in each arm at the end of the study if the same proportion of participants are enrolled from JHHED. Factoring in a 15% lost-to-follow-up, 112 participants will be enrolled into each arm.We will use a bivariate analysis to explore the potential association between the independent variable (POC HIV VL test) and other covariates with the outcome variable of interest. A multivariate regression is planned to determine the association between having a POC HIV VL test and linkage to PrEP or ART, with adjustment for covariates and confounders. A survival analysis will be performed (Cox proportional hazard model) to model the time to linkage to ART or PrEP by study arm, with adjustment of covariates and confounders.The performance of the OraQuick ADVANCE® Rapid HIV-1/2 Antibody Test and the DPP® HIV-Syphilis System will be evaluated by calculating the positive percent agreement, negative percent agreement, positive predictive value (PPV), and negative predictive value (NPV) compared to the standard laboratory HIV testing algorithm.