Duke 2008 | ASHE | Equity and Efficiency in Health and Healthcare

Context: Most cost and cost-effectiveness studies of substance abuse treatment interventions focus only on the direct costs to the provider. Although this perspective is important especially for funding agents and policy makers, the costs incurred by patients should also be considered when evaluating an intervention. These costs may be substantial to the patient as well as society as a whole and may affect a patient’s willingness to seek treatment or to fully complete an intervention already underway. Unfortunately, collecting these cost data can be challenging and to date few economic evaluations of substance abuse treatment have done so. The COMBINE study provides a unique opportunity to estimate cost-effectiveness from the patient perspective.

Objective: The purpose of this analysis is to estimate the patients’ costs associated with the COMBINE alcohol treatment interventions and to evaluate the cost-effectiveness of these different interventions from the patient’s perspective.

Design, Setting, and Participants: A prospective cost and cost-effectiveness study of patients in COMBINE, a randomized controlled clinical trial (RCT) involving 1383 patients with diagnoses of primary alcohol dependence across 11 U.S. clinical sites. To compute the patients’ costs associated with the COMBINE interventions, we follow a micro-costing approach that allows cost estimation for individual intervention activities. Data on patient time, wage, and clinical treatment were collected from clinical records and patient surveys. Efficacy of the primary clinical outcomes from COMBINE (see Anton et al., 2006) are used for the effectiveness of treatment.

Interventions: Nine treatment arms, with four arms receiving medical management with 16 weeks of naltrexone or acamprosate, both, and/or placebo; four arms receiving the same options as above but delivered with combined behavioral intervention (CBI), and a ninth arm receiving CBI only. Main Outcomes Measures: Incremental cost per percentage point increase in percent days abstinent, incremental cost per patient of avoiding a heavy drinking day, and incremental cost per patient of achieving a good clinical outcome.

Results: Seven of the 9 treatment interventions are dominated in a strict or extended sense relative to other interventions in the study and are therefore not economically viable; only 2 interventions remain economically viable: MM + naltrexone ($771 per patient) and MM + naltrexone + acamprosate ($1,461 per patient). The incremental cost effectiveness ratio (ICER) of MM + naltrexone + acamprosate relative to MM + naltrexone is $326 per percentage point increase in percent days abstinent, $3971 per patient of avoiding a heavy drinking day, and $3700 per patient of achieving a good clinical outcome.

Conclusions: This study presents the first cost-effectiveness analysis from the patient perspective of interventions for alcohol dependence. Although all of the COMBINE therapies reduced drinking, only 2 interventions are found to be potentially cost-effective for patients, the remaining 7 are not economically viable alternatives. Focusing just on effectiveness, MM + naltrexone + acamprosate is not significantly better than MM + naltrexone (Anton et al., 2006). However, looking at cost and effectiveness, MM + naltrexone + acamprosate may be a cost-effective choice, depending on whether the cost of the incremental increase in effectiveness is worth it to the patient.