Challenges in measuring medication adherence: experiences from a controlled trial
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Measurement of adherence is complex and many methods, both direct and indirect are used; there is no universal gold standard. In this article, we share our experiences in a randomised controlled study, the Hypertension Adherence Program in Pharmacy trial, evaluating a community pharmacy-based intervention for improving adherence to antihypertensive medication. Several objective and subjective measures of adherence (Morisky score, TABS score, MedsIndex, Medicines Possession Ratio) were used, but produced varying results, limiting confidence in the conclusions that could be drawn. Despite using a specifically designed data mining software program to identify potentially nonadherent patients from dispensing records, many participants were found to be adherent by the self reported Morisky scale. A lesson to be learned when targeting people for interventions to improve adherence is that information from dispensing records should be supplemented by other methods in order to identify patients most in need of assistance.
KeywordsMedication adherence Adherence measures Randomised controlled trial
We acknowledge the other researchers on the HAPPy trial: Michael J. Bailey, Rosalind Lau, Jenny McDowell (Monash University), Diana Bortoletto (Monash University; Barwon Health); Shane L. Jackson, Gregory M. Peterson, Luke Bereznicki, Peter Gee (University of Tasmania); Jeffery D. Hughes (Curtin University); Ya-Seng (Arthur) Hsueh (The University of Melbourne).
The HAPPy Trial was funded by the Australian Government Department of Health and Ageing through the Fourth Community Pharmacy Agreement Research & Development Grants Program managed by The Pharmacy Guild of Australia.
Conflicts of interest
The authors declare no conflict of interests.
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