Perception of pharmacological prevention and subsequent non-adherence to medication in patients with ischaemic heart disease: a population-based cohort study

Objective A patient-focused approach is advocated to embody risk of non-adherence to medication and subsequent adverse clinical outcomes following ischaemic heart disease (IHD). This study aimed to explore how patient perceived information on pharmacological prevention was associated with subsequent non-adherence to medication (measured by non-initiation, non-implementation and non-persistence) in patients with incident IHD. Design Cohort study. Setting Denmark. Participants Register-based cohort of 829 patients with incident IHD in 2013. Measures Perception covered whether patients' experienced being adequately informed about their pharmacological prevention. Information on such was obtained from a survey and divided into 'Well informed', 'Moderately informed' and 'Poorly informed'. Information on baseline characteristics, and reimbursed prescriptions of medication (antiplatelets, statins, ACE-inhibitors/angiotensin receptor blockers and beta-blockers) during follow-up were obtained by linkage to nationwide public registers. Non-initiation and non-implementation of medication, measured as proportion of days covered, were analysed by Poisson regression. Non-persistence to medication, measured as risk of discontinuation, was analysed by multivariable Cox proportional hazard regression. Primary and secondary outcome measures Non-implementation and non-persistence to medication up to 365 days of follow-up were primary outcomes. Secondary outcomes included non-initiation as well as non-implementation and non-persistence to medication at 180 days of follow-up. Results A dose-response association was in general found between perception of pharmacological prevention and risk of non-implementation and non-persistence. For example, the hazard of non-persistence to antiplatelets was 1.18 (95% CI 0.71 to 1.96) times higher for patients reporting 'Moderately informed' and 1.89 (95% CI 1.10 to 3.25) times higher for patients reporting 'Poorly informed', compared with patients reporting 'Well informed of perception of pharmacological prevention' up to 365 days of follow-up. Conclusion Lower levels of perception of pharmacological prevention were associated with subsequent non-implementation and non-persistence to medication in patients with incident IHD.