Improving adherence to antidepressant drug treatment in primary care: a feasibility study for a randomized controlled trial of educational intervention

Poor adherence to prescribed medication is a well-documented waste of resources and may be particularly prevalent in depressive illness. Studies in primary care have suggested rates of non-adherence to antidepressants of 50-70%. We undertook a feasibility study of a randomized controlled trial of a novel intervention. Patents prescribed antidepressants in primary care were randomly allocated to receive a computer-generated educational intervention or to routine practice. Patients in the intervention groups received simple tailored information 1, 6 and 16 weeks after the initial prescription, which was personalized for each patient and specific drug and generated by a specially constructed computer programme. Comparisons were made in terms of collection of prescriptions over 6 months, mental health status (the Hospital Anxiety and Depression Scale (HADS)), frequencies of consultation, referrals and admissions and satisfaction with treatment. The five participating practices referred 61 patents to the study over 12 months, 45 of whom entered and completed the study. There were no statistically significant differences between the groups in the proportions of patients who collected prescriptions over 6 months, with the overall rates declining from 91% in month 1 to 56% in month 6. Patients in the intervention group had significantly lower HADS scores at 6 months. There were no significant differences in the numbers of consultations, referrals and admissions. Thus, whilst there were indications that the intervention might yield benefits for patients, the study was of insufficient statistical power to yield unequivocal results. The difficulties of recruiting patients in primary care are discussed and options for further research considered.