Effectiveness of an Intervention to Improve HIV Service Delivery for People Who Inject Drugs in Kazakhstan A Cluster Trial

IMPORTANCE The increasing HIV incidence rates and suboptimal rates of testing, engagement, and retention in care for people who inject drugs (PWID) in Kazakhstan underscore the need for effective HIV care continuum interventions for PWID. OBJECTIVE To determine the effectiveness of the Bridge HIV care continuum intervention implemented in needle and syringe programs (NSPs) in Kazakhstan. DESIGN, SETTING, AND PARTICIPANTS This stepped-wedge cluster trial was conducted from February 2017 to May 2020, with implementation beginning sequentially across 3 cities (Almaty, Karaganda-Temirtau, and Shymkent) in August 2017, January 2018, and May 2019. Intervention effect sizes were estimated via population-averaged models, and hypothesis testing relied on a permutation testing approach. The primary unit of analysis was an NSP. Data analysis was performed from October 2020 to April 2022. INTERVENTIONS The intervention addresses the full HIV care continuum: identification, testing, referral to services, and linkage to HIV care. The 3 intervention components were (1) a social network strategy, a peer-driven recruitment approach for HIV testing; (2) HIV counseling, rapid testing, and referral following international and national guidelines and protocols; and (3) enhanced antiretroviral treatment and access to services. MAIN OUTCOMES AND MEASURES The primary outcomes were the effectiveness of implementing Bridge's enhanced service integration approach in increasing the number of PWID served at NSPs, increasing the number of PWID who are tested for HIV in NSPs, and improving linking HIV-positive PWID with HIV care. Secondary outcomes included numbers of clients registered for HIV care, initiation of antiretroviral therapy, and viral suppression. RESULTS Twenty-four NSPs (8 in each city) served a total of 1225 PWID (369 in Almaty, 618 in Karaganda-Temirtau, and 238 in Shymkent) at the preimplementation study step; 1015 clients (82.9%) were male, and the mean (SD) age was 36.7 (7.1) years. Compared with preimplementation study steps, during Bridge intervention implementation steps, NSPs experienced a significant increase in the number of PWID clients registered (incidence rate ratio, 2.37; 95% CI, 1.48-3.78) and the number of PWID who received rapid HIV tests (incidence rate ratio. 3.98; 95% CI, 2.30-6.90). No significant increase in referral to HIV care was observed. The study also found significant support for secondary outcomes of antiretroviral therapy initiation and the number of clients who achieved viral suppression. CONCLUSIONS AND RELEVANCE In this stepped-wedge cluster trial, the findings suggest that implementation of the Bridge intervention was associated with significant improvement in several steps in the continuum of HIV care for PWID in Kazakhstan.