Better quality of life in patients offered financial incentives for taking anti-psychotic medication: Linked to improved adherence or more money?

In a randomised controlled trial, patients were offered financial incentives to improve their adherence to anti-psychotic maintenance medication. Compared to a control group without the incentives, they had an improved adherence and also better subjective quality of life (SQOL) after 1 year. This paper explores the question as to whether this improvement in SQOL was associated with the amount of money received or with the improved adherence itself. A secondary analysis was performed using data of the experimental group in the trial. Adherence was assessed as the percentage of all prescribed long-acting anti-psychotic injections that were taken by the patient. In regression models, we tested whether changes in medication adherence and/or the amount of incentives received over the 12-month period was associated with SQOL, as rated on the DIALOG scale. Adherence changed from 68.49 % at baseline to 88.23 % (mean difference in adherence = 19.59 %, SD = 17.52 %). The total amount of incentives received within the 1-year study period varied between A 75 pound and A 735 pound, depending on the treatment cycle and the number of long-acting injections taken. Improvement in adherence was found to be a significant predictor of better subjective quality of life (beta = 0.014, 95 % CI 0.003-0.025, p = 0.014), whilst the amount of incentives received was not (beta = 0.0002, 95 % CI -0.002 to 0.002, p = 0.818). Improved medication adherence is associated with a more favourable SQOL. This underlines the clinical relevance of improved adherence in response to financial incentives in this patient group.