Estimating the cost due to resistance against antiretroviral therapies in individuals with HIV: Perspective of the Kingdom of Saudi Arabia.

Objectives: The emergence of resistance to antiretroviral therapy (ART) has an impact on the cost of HIV care. This study aimed to estimate the direct and indirect costs associated with the first episode of drug resistance in individuals with HIV receiving first-line ART. Methods: We developed a cost calculator to estimate the cost of drug resistance over a period of 12 months in the Kingdom of Saudi Arabia. The model inputs (estimated using expert opinion and publicly available sources) included costs associated with testing for resistance, adverse events of a new regimen, and indirect costs. Results: The direct and indirect medical expenses for the year resistance developed were 6980 Saudi Arabian riyal (SAR) and SAR 2862, respectively. The addition of the cost of new ARTs would increase the total annual costs (between SAR 5174 and SAR 34,265 per patient). One-way sensitivity analysis also reported significant impact of initial and switching therapies used after resistance develops on the total costs of resistance per year. Conclusions: There is a significant cost burden associated with drug resistance, which emphasizes the need to select an appropriate initial ART regimen that has a strong genetic barrier and conduct pre-treatment resistance tests (if possible).