The cost of HIV medication adherence support interventions: results of a cross-site evaluation

The objective of this study was to determine the direct cost of HIV adherence support programmes participating in a cross-site evaluation in the US. Data on the frequency, type, and setting of adherence encounters; providers' professions; and adherence tools provided were collected for 1,122 patients enrolled in 13 interventions at 9 sites. The site staff estimated the average duration of each type of encounter and national wage rates were used for labour costs. The median (range) adherence encounters/year among interventions was 16.5 (4.3-104.6) per patient; encounters lasted 24.6 (8.9-40.9) minutes. Intervention direct cost was correlated with the average frequency of encounters (r = 0.57), but not with encounter duration or providers' professions. The median direct cost/month was 35 dollars(5 dollars-58 dollars) per patient, and included direct provider costs (66%); incentives (17%); reminders and other tools (8%); and direct administrative time, provider transportation, training, and home delivery (9%). The median direct cost/month from a societal perspective, which includes patient time and travel costs, was 47 dollars(24 dollars-114 dollars) per patient. Adherence interventions with moderate efficacy costing < or =100 dollars/month have been estimated to meet a cost-effectiveness threshold that is generally accepted in the US. Payers should consider enhanced reimbursement for adherence support services.