Within-Trial Cost-Effectiveness of an Adherence-Enhancing Educational Intervention for Glaucoma

Abstract

PurposeTo assess the within-trial cost-effectiveness of a behavioral intervention to improve glaucoma medication adherence. DesignProspective cost-effectiveness analysis of randomized, controlled trial data. MethodsThe study setting was a Veterans Affairs (VA) eye clinic. The patient population comprised veterans with medically treated glaucoma and self-reported poor adherence. Participants were randomized to a personalized educational session with a reminder bottle to promote medication adherence or to a control session on general eye health. Costs were assessed from the perspective of the VA payor at 6 months using the VA Managerial Cost Accounting System. Probabilistic sensitivity analyses were conducted using bootstrapped samples. The main outcome measures were the proportion of participants attaining ≥80% adherence as measured by electronic monitor, total intervention and medical resource costs, and incremental cost-effectiveness ratios comparing intervention to control at 6 months. ResultsOf 200 randomized participants, 95 of 100 assigned to the intervention and 97 of 100 assigned to the control had adherence outcomes at 6 months, and the proportion of adherent patients was higher in the intervention group compared to control (0.78 vs 0.40, P < .0001). All participants had costs at 6 months. The total cost at 6 months was $1,149,600 in the intervention group (n = 100) compared to $1,298,700 in the control group (n = 100). Thus, in a hypothetical cohort of 100 patients, the intervention was associated with cost savings (−$149,100) and resulted in 38 additional patients achieving medication adherence. ConclusionsAn adherence-enhancing behavioral intervention was effective and cost saving at 6 months.