Background: Noncompliance with medication has been a complex issue with patients with severe mental illness during the last few decades, and adverse effects of medication have been identified as a major contributor to noncompliance.
Objectives: To assess the sources of patients' knowledge of the adverse effects of their prescribed medicines and the perceived effects of their knowledge and experiences of adverse effects on their compliance with prescribed medicines.
Methods: A cross-sectional survey of 500 patients attending outpatient psychiatric services in an urban adult mental health services in Ireland was carried out to assess parameters relevant to the objectives of the study.
Results: Of the 500 patients approached, 409 agreed to take part in the study, giving a response rate of 81.8%. Mean (SD) age was 41 (12) years, with 39% being males, and 74.9% having at least secondary education. Overall, 44% said they had learnt of adverse effects of their medication from multiple sources including physicians (52.31%), leaflets (54.2%), Internet (14.29%), books (13.02%), and chemist/pharmacist (11.34%). Of the patients, 46.2% reported that they have had concerns about taking their medication because of their knowledge of adverse effects, with females more likely to have such concerns than males. Moreover, 14.7% of patients reported that they had ever refused to take medication prescribed for them because of their knowledge of adverse effects, whereas 30.8% of patients reported that they had some time in the past stopped taking their medication because they had actually experienced adverse effects. Finally, when asked if they would have taken the medicines prescribed for them now if they were told initially of all the adverse effects, 50.60% answered "more likely," with a higher proportion of these being males.
Conclusions: Physicians and information leaflets are the leading sources of patients' knowledge about adverse effects of medication. The knowledge of adverse effects of medication has a potential to affect compliance, and so it is essential for physicians to engage patients in a fuller communication about their illness and its treatment with medication including the management of potential adverse effects.