Effectiveness and cost-effectiveness of the Initial Medication Adherence intervention: a cluster randomised control trial, economic model and process evaluation(IMA-cRCT).

BACKGROUND. Nowadays 10% of the prescriptions for chronic treatments prescribed in Catalonia are not initiated. This behaviour of no initiation has a negative impact on the population health and health expenditure. HYPOTHESIS. The Initial Medication Adherence intervention (IMA) is effective and efficient to improve initiation, secondary adherence, and clinical outcomes in patients receiving treatment for the prevention and/or treatment of cardiovascular disease and diabetes. Its implementation in clinical practice in primary care centres and community pharmacies is feasible. OBJECTIVE. Evaluate the effectiveness, cost-effectiveness and feasibility of the IMA intervention, compared to the usual treatment, through a cluster randomized controlled trial complemented by a process evaluation and an economic modelling study. METHODOLOGY. Intervention hybrid design that includes a cluster randomized control trial (clinical trial) with a process evaluation, and a Markov model. The IMA intervention is a shared decision-making intervention based on the theoretical model of non-initiation. The clinical trial will be conducted in 34 primary care centres, which will be randomly assigned to the control or intervention group, and the community pharmacies of the reference area of the primary care centres in the intervention group. The professionals of the intervention group will receive training in non-initiation, shared decision-making and the IMA intervention. These professionals will apply the IMA intervention on all patients who receive a first prescription of a new treatment for cardiovascular disease and diabetes during the study period (January-July 2022). To carry out a process evaluation and understand the components of the intervention that influence the results; we will collect data on the implementation, the mechanism of impact and the context of the intervention. A Markov model that considers adherence as a dynamic process will be built, it will be informed with the clinical trial data and data from previous studies to assess long-term cost-effectiveness. EXPECTED RESULTS. The study will provide evidence on the IMA intervention as well as on a new methodology for developing and evaluating complex interventions in the future. APPLICABILITY AND RELEVANCE. The results of the study will be disseminated among stakeholders, including decision-makers, health professionals and patient groups, to facilitate transferability to clinical practice.

Intervention Behavioural change (patients) - The IMA intervention is a shared-decision making intervention that promotes health literacy and patient participation in the decision making process during the recommendation and prescription of a new drug for the management of a cardiovascular disease and diabetes. The IMA intervention has four main components: training for healthcare professionals (general practitioners (GP), nurses and community pharmacists) on non-initiation, shared-decision making, health literacy and use of decision aids; intervention decision aids (leaflets and website); implementation of the IMA intervention during the GP's consultation; and information support provided by the nurses and community pharmacists that will use the intervention decision aids to explore the patients's doubts and harmonise and standardise the discourse between primary healthcare professionals.
Number of sites 28
Countries involved 1
Sample size 4000
Type of statistical analyses
Risk of bias Overall: - details
Participant characteristics Age: >18
Condition: Cardiovascular disease or diabetes
Baseline severity: low
Duration of trial 1 year
Primary outcome Adherence
Effect Measures
Events Intervention Total Events Control Total Risk Diff.
Reduction in the incidence of non-initiation of 3 perceptual points
Show Score Ranges


(shows median if more than one score was entered)

Elig. Recr. Setting Org. Int. Flex. Del. Flex. Adherence Follow-Up Prim. Out. Prim. An.
5 5 5 4 4 5 5 2 5