Preferences of people living with HIV for features of tuberculosis preventive treatment regimens - a discrete choice experiment.

Background: Tuberculosis (TB) preventive treatment (TPT) is recommended for people living with HIV (PLHIV) in high TB burden settings. While 6 months of daily isoniazid remains widely used, shorter regimens are now available. However, little is known about preferences of PLHIV for key features of TPT regimens.
Methods: We conducted a discrete choice experiment among adult PLHIV engaged in care at an urban HIV clinic in Kampala, Uganda. In nine random choice tasks, participants chose between two hypothetical TPT regimens with different features (pills per dose, frequency, duration, need for adjusted antiretroviral therapy [ART] dosage and side effects). We analyzed preferences using hierarchical Bayesian estimation, latent class analysis, and willingness-to-trade simulations.
Results: Of 400 PLHIV, 392 (median age 44, 72% female, 91% TPT-experienced) had high quality choice task responses. Pills per dose was the most important attribute (relative importance 32.4%, 95% confidence interval [CI] 31.6 - 33.2), followed by frequency (20.5% [95% CI 19.7 - 21.3]), duration (19.5% [95% CI 18.6 - 20.5]), and need for ART dosage adjustment (18.2% [95% CI 17.2 - 19.2]). Latent class analysis identified three preference groups: one prioritized less frequent, weekly dosing (N=222; 57%); another was averse to ART dosage adjustment (N=107; 27%); and the last prioritized short and tolerable regimens (N=63; 16%). All groups highly valued fewer pills per dose. Participants were willing to accept a regimen of 2.8 months' additional duration [95% CI: 2.4 - 3.2] to reduce pills per dose from five to one, 3.6 [95% CI 2.4 - 4.8] months for weekly rather than daily dosing, and 2.2 [95% CI 1.3 - 3.0] months to avoid ART dosage adjustment.
Conclusions: To align with preferences of PLHIV, decision-makers should prioritize the development and implementation of TPT regimens with fewer pills, less frequent dosing, and no need for ART dosage adjustment, rather than focus primarily on duration of treatment.