Process evaluation of the INTENSE study aimed at improving adherence to oral diabetes and/or hypertension medication in people with type 2 diabetes

Introduction: The aim of this study was to evaluate the implementation and the potential of a pharmacist-led personalised intervention program, aimed at improving medication adherence to oral diabetes and/or hypertension medication in people with type 2 diabetes (T2D), to be normalized in daily clinical practice. Material and methods: A parallel-group randomized controlled trial (RCT) was conducted in 68 participants in 26 community pharmacies from the Netherlands (NL) and the UK. This manuscript reports on a multi-method process analysis that was performed parallel to the six-month follow-up of the RCT. Quantitative data, including data from the data management platform, were analyzed with descriptive statistics. Qualitative data were collected via semi-structured interviews with purposively selected pharmacists (high/low numbers of recruited participants) and participants (high/low satisfaction) and audio-recorded consultations between pharmacists and participants. Semi-structured interviews were analyzed using the Framework approach, the Medical Research Council process evaluation framework of complex interventions and Extended Normalization Process Theory. Audio-recorded consultations were analyzed using the OPTION-12 scale and a self-composed checklist. Results: The fidelity and dose of the intervention program were assessed as high. Consultations were conducted according to the study protocol. Participants satisfaction with the intervention modules varied, but overall, participants were satisfied with the clinical medication review, medication schedule, medication dispensing system and referral to their primary care physician. The reach was assessed as low, resulting from selection procedure difficulties and only 68 out of the intended 300 participants were recruited. Selection procedure adaptations did not increase the reach. The potential of the intervention program was assessed as high, since pharmacists valued the development of a medication adherence intervention. Contribution was also assessed as high, because of collective action from stakeholders. Finally, capability and capacity were assessed as moderate, due to material resource and workability barriers. Discussion: In its current form the pharmacist-led personalised intervention program cannot be implemented and normalized into daily care. In this process evaluation several barriers including the selection procedure and recruitment of participants have been identified that need to be resolved before the effectiveness of this personalised intervention program can be re-evaluated. Future research should therefore focus on alternative methods for engaging people with T2D with insufficient medication adherence in medication adherence interventions. Keywords: Medication adherence, process evaluation, implementation, community pharmacy, type 2 diabetes mellitus