OBJECTIVES: We analyzed carbon dioxide (CO₂) emissions data to compare the environmental costs of different antiretroviral therapy (ART) refill methods for people living with HIV.

METHODS: Deliver Health Study participants in KwaZulu-Natal, South Africa, were randomized to receive three-month ART refills and monitoring at home or standard clinic-based care. HIV plasma viral load was measured at month 12 exit. We compared cumulative CO₂ emissions for quarterly visits over 12 months for participants receiving home vs. clinic-based services. Six- and 12-month refill scenarios were evaluated. We used delivery log data to compute distances from participants’ homes/workplaces to clinics and home delivery routes. Distances were multiplied by estimated CO₂ emissions of the transport mode (driving, public transit, or Ford Ranger delivery vehicles), and the cumulative CO₂ emissions estimated. The incremental cost-effectiveness ratio was calculated as the change in average CO₂ emissions divided by the change in the number of people virally suppressed per group.

RESULTS: Of 154 participants, 83 (54%) were men, the median age was 36 years, and 81 (53%) received home-ART delivery and monitoring. Seventy-one persons were virally suppressed in the home-delivery group compared to 54 in the clinic group. Average cumulative carbon emissions in the home group were 7.25 kilograms of CO₂ per person compared to 0.39 kilograms of CO₂ in the clinic group. The incremental carbon-cost was 50.16 kilograms of CO₂ per person virally suppressed through home delivery, equivalent to driving 271 extra kilometers in the delivery vehicle. If 6- or 12-month refills were provided instead, incremental emissions for home-delivered ART would be 25.08 and 12.54 kilograms of CO₂, equivalent to 136 and 68 kilometers driven, respectively.

CONCLUSIONS: In rural South Africa, incremental CO₂ emissions were higher for participants receiving home-delivered vs. clinic-based ART refills but could be offset by 6- or 12-month refills and/or changing number of deliveries or vehicle type.