Cost-effectiveness analysis of pre-ART HIV drug resistance testing in Kenya

Abstract

Aim: The prevalence of HIV pre-treatment drug resistance (PDR) is increasing in East Africa, which may decrease the effectiveness of antiretroviral therapy (ART) programs. Our objective was to evaluate whether testing for PDR with an oligonucleotide ligation assay (OLA), a low-cost point mutation assay, is a cost-effective strategy to address the challenges posed by PDR in resource-poor settings. Methods: We developed an HIV drug resistance model that simulates the emergence and transmission of resistance mutations, calibrated to the Kenyan epidemic. We implemented 3 care strategies for PDR testing: current policy (no PDR testing), PDR testing with OLA, and PDR testing with consensus sequencing (CS), each with initial viral load (VL) testing performed at 6 months after ART initiation and every 12 months thereafter. This model was used to evaluate the health outcomes, lifetime costs, and cost-effectiveness of the strategies over a 15-year time horizon starting in 2018. Results: OLA PDR testing had an incremental cost-effectiveness ratio (ICER) of $1,790/QALY gained, which is cost-effective by national income standards. PDR testing with CS was not cost-effective. OLA PDR testing resulted in more patients maintaining viral suppression at 12 months after ART initiation compared to the current policy (82% vs. 77%, respectively). PDR testing with OLA was also associated with 3% fewer new HIV infections than the current policy. Initial PDR prevalence was 9.2% in 2018. By 2033, this prevalence increased to 20.3% when continuing the current policy, but only to 18.6% with OLA PDR testing. Conclusions: Low-cost PDR testing is cost-effective compared to no PDR testing in settings where dolutegravir is not available. Over time, testing for PDR has the potential to reduce the growth of PDR prevalence in resource-poor settings.