Objective: Uncertainty about the value of antiretroviral therapy (ARV) adherence interventions may be a barrier to implementation and evaluation. Our objective is to estimate the minimum effectiveness required for ARV adherence interventions to deliver acceptable value.
Methods: We used a validated HIV computer simulation to estimate the impact of ARV adherence interventions on incremental costs and life expectancy. Across a wide range of intervention costs ($1000–10,000, one time or per year), we estimated the smallest effect size compatible with acceptable value (incremental cost‐effective ratio ≤$100,000 per life‐year). Effect sizes were measured using relative risk (RR) and absolute risk reduction (ARR), and these metrics were applied to nonadherence and nonadherence risk factors. Costs were estimated from a societal perspective ($2003) discounted at 3%.
Results: To give acceptable value, a one‐time $1000 intervention must reduce ARV nonadherence by RR ≤ 0.82 (ARR ≥ 0.04) for moderately nonadherent patients (20% of ARV doses missed) and RR ≤ 0.90 (ARR ≥ 0.05) for severely nonadherent patients (50% of ARV doses missed). A one‐time $5000 intervention has an unacceptable value regardless of effect size for moderately nonadherent patients, and must reduce ARV nonadherence by RR ≤ 0.31 (ARR ≥ 0.69) for severely nonadherent patients. Interventions aimed at behavioral risk factors (e.g., unhealthy alcohol use) may confer acceptable value (e.g., if ≤$2000 and effect RR ≤ 0.71 [ARR ≥ 0.29]).
Conclusions: ARV adherence interventions with plausible effect sizes may offer favorable value if they cost <$5000 one time or per year. ARV adherence interventions with a favorable value should become more integral components of HIV care.