Effectiveness of a medication-adherence tool: study protocol for a randomized controlled trial

Background: Research shows that more than half of the people taking medication for a chronic condition are non-adherent. Nonadherence hinders disease control with a burden on patient quality of life and healthcare systems. We developed a tool that provides insight into nonadherence risks and barriers for medication-adherence including an intervention strategy to overcome those barriers. This study aims to assess the effectiveness of using this adherence tool in starters with cardiovascular or oral blood glucose-lowering medication to improve medication-adherence. Methods/design: In a cluster-randomized controlled trial 25 pharmacies in the Netherlands will be randomized to the intervention or control arm. Patients registered in a general practice participating in a collaborative can be included when they start cardiovascular or oral blood glucose-lowering medication prescribed by their general practitioner. Participants complete an assessment consisting of measuring nonadherence risk and potential barriers to adherence. For patients with an increased nonadherence risk, a graphic barrier profile is created, showing to what extent eight cognitive, emotional, or practical barriers are present. All patients will fill in the medication-adherence assessment twice: between 1 and 2 weeks after the start of the medication and after 8 months. The intervention strategy consists of discussing this barrier profile to overcome barriers. Pharmacists and assistants of the intervention pharmacies are trained in discussing the profile and to offer a tailored intervention to overcome barriers. In the control arm, patients receive care as usual. The primary outcome is medication-adherence of patients with a high risk of nonadherence at 8 months follow-up. Secondary outcomes include the difference in the percentage of patients with an increased nonadherence risk between intervention and control group after 8 months, the predictive values of the baseline questionnaire in the control group in relation to medication-adherence after 8 months, medication-adherence after 1 year follow-up, and barriers and facilitators in the implementation of the tool. Discussion: This manuscript presents the protocol for a cluster-randomized clinical trial on the use of an adherence tool to improve medication-adherence. This study will provide insight into the effectiveness of the tool in starters with cardiovascular or oral blood glucose-lowering medication in improvement of medication-adherence.