Optimizing HIV case identification: investigating client characteristics predictive of HIV positivity from provider-initiated testing (PITC) in central Kenya.

Background: Routine program data indicates positivity rates under 2% from HIV testing services (HTS) at sites supported by Centre for Health Solutions-Kenya in Central Kenya. Achieving the UNAIDS 95:95:95 goals requires continuous identification of people living with HIV in an environment of diminishing resources. We assessed non-clinical and clinical characteristics of persons who tested HIV-positive aimed at improving the process of HTS through Provider-Initiated HIV Testing & Counseling (PITC).

Methods: We conducted a retrospective analysis of routine PITC program data collected between October 2018 and September 2019 from six health facilities located in three counties in central Kenya. Stratification was based on county and facility volume. A multivariable logistic regression model, clustered adjusted for facility using robust standard errors, was used to determine predictors of a positive HIV result.

Results: The total sample was 80,693 with an overall positivity rate of 1.2%. Most, (65.5%), were female and 6.1% were < 15 years. Most clients, 55,464 (68.7%), had previously tested for HIV. Client characteristics associated with a higher odds of positivity on multivariable analysis included: being female (adjusted odds ratio [aOR] 1.27, 95% confidence interval [CI] (1.03-1.57); adults 15 years and above compared to children < 15 years, divorced and married polygamous compared to married monogamous [aOR 3.98, 95% CI (2.12-7.29) and aOR 2.41 95% CI (1.48-3.94) respectively]; clients testing for the first time compared to repeat testers in less than 12 months [aOR 1.39, 95% CI (1.27-1.51)]. Similarly, repeat testers in more than 12 months compared to repeat testers in less than 12 months [aOR 1.90, 95% CI (1.55-2.32)]; presumptive TB clients compared to those without signs of TB [aOR 16.25, 95% CI (10.63-24.84)]. Clients tested at inpatient departments (IPD) were more likely to get a positive HIV result compared to those tested at outpatient departments (OPD), and other departments.

Conclusions: The study findings highlight client characteristics such as age, marital status, HIV test entry point, first-time test, repeat test after 12 months, and TB status as factors that could influence PITC results and could be used to develop a screening tool to target eligible clients for HTS in low HIV prevalence settings.