Organisational determinants of adherence to secondary prevention medications after acute myocardial infarction

OBJECTIVES: to identify organisational determinants of adherence to evidence-based drug treatments after acute myocardial infarction (AMI), under the hypothesis that low adherence is associated with higher mortality and risk of reinfarction. In particular, we investigated the effect of group vs. single handed practice and multi-professional practice characteristics on patients' adherence to polytherapy after AMI. DESIGN: retrospective cohort study. SETTING AND PARTICIPANTS: residents in the Local Health Authority of Bologna (Italy) who were discharged from any Italian hospital between 2008 and 2011 with a diagnosis of AMI, and followed-up for a year. MAIN OUTCOME MEASURES: adherence to at least three out of the four drug therapies recommended for secondary prevention of AMI (angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, β-blockers, antiplatelet agents, statins). Patients who had at least 80% of days of follow-up covered by drug doses were considered adherent. RESULTS: of the 4,828 post-AMI patients, 31.6% were adherent to polytherapy. General practice characteristics were unrelated to adherence, whereas discharge from cardiology hospital wards was significantly associated with higher patients' adherence (OR 1.97; 95%CI 1.56-2.48). CONCLUSION: general practice organisational models are not associated with higher adherence to evidence-based medications after AMI, whereas cardiologists seem to play a key role in improving patient adherence to polytherapy. Healthcare delivery models should be designed; in them, general practitioners are responsible for the provision of patient-centred care pathways and for care co-ordination with other primary care professionals and specialists, and take an advocacy role for the patient when needed.