Differentiated care preferences of stable patients on ART in Zambia: a discrete choice experiment

Background: Although differentiated service delivery (DSD) models for stable patients on antiretroviral therapy (ART) offer a range of health systems innovations, their comparative desirability to patients remains unknown. We conducted a discrete choice experiment to quantify service attributes most desired by patients to inform model prioritization Methods: Between July and December 2016 a sample of HIV-positive adults on ART at 12 clinics in Zambia were asked to choose between two hypothetical facilities which differed across six DSD attributes. We used mixed logit models to explore preferences, heterogeneity and trade-offs Results: Of 486 respondents, 59% were female and 85% resided in urban locations. Patients strongly preferred infrequent clinic visits (3 vs. 1-month visits: β (i.e. relative utility) =2.84; p <0.001). Milder preferences were observed for: waiting time for ART pick-up (1 vs. 6 hrs.; β=-0.67; p<0.001) or provider (1 vs. 3 hrs.; β=-0.41; p=0.002); ‘buddy’ ART collection (β=0.84; p <0.001); and ART pick-up location (clinic vs. community: β=0.35; p=0.028). Urban patients demonstrated a preference for collecting ART at a clinic (β=1.32, p<0.001), and although the majority of rural patients preferred community ART pick-up (β=-0.74, p=0.049), 40% of rural patients still preferred facility ART collection. Conclusions: Stable patients on ART primarily want to attend clinic infrequently, supporting a focus in Zambia on optimizing multi-month prescribing over other DSD features - particularly in urban areas. Substantial preference heterogeneity highlights the need for DSD models to be flexible, and accommodate both setting features and patient choice in their design.