Medical and social costs after using financial incentives to improve medication adherence: results of a 1 year randomised controlled trial.

OBJECTIVE: Offering a financial incentive ('Money for Medication') is effective in improving adherence to treatment with depot antipsychotic medications. We investigated the cost-effectiveness in terms of medical costs and judicial expenses of using financial incentives to improve adherence. The effects of financial incentives on depot medication adherence were evaluated in a randomised controlled trial. Patients in the intervention group received €30 a month over 12 months if antipsychotic depot medication was accepted. The control group received mental health care as usual. For 133 patients outcomes were calculated based on self-reported service use and delinquent behaviour and expressed as standard unit costs to value resource use.

RESULTS: The financial incentive resulted in higher average costs related to mental health care (€449.6 versus €355.7). and lower medical costs related to other healthcare services (€52.0 versus €78.4). Relevant differences in social costs related to delinquent behaviour were not found. Although wide confidence intervals indicate uncertainty, incremental cost-effectiveness ratio's (ICER) indicate that it costs €2080 for achieving a 20% increase in adherence or €3332 for achieving over 80% adherence. In sum, offering money as financial incentive for increasing compliance did not lead to an overall cost reduction as compared to care as usual. Trial registration NTR2350, 01 June 2010.