https://orcid.org/0000-0002-6679-454X
Abstract
Purpose
Medication adherence is crucial for achieving clinical goals. Medication adherence drivers and behaviors were explored across multiple conditions, countries, and medication schedules/modalities to develop a conceptual model of medication adherence, which could later be used to support development of a patient-reported outcome (PRO) measure of adherence.
Patients and Methods
Targeted review of qualitative literature identified important medication adherence concepts. Fifty-seven qualitative concept elicitation interviews were conducted (USA n=21, Spain n=18, Germany n=18). Participants were prescribed medication for: hypertension (n=9), asthma (n=8), multiple myeloma (n=8), psoriasis (n=8), diabetes (n=7), depression (n=7), multiple sclerosis (n=7), and/or schizophrenia (n=6). Thematic analysis of verbatim transcripts was performed. Expert clinicians (n=3) provided input throughout.
Results
Nine qualitative articles were selected for review from 2168 screened abstracts. Forty-two medication adherence concepts were reported and grouped into 10 domains. Eight forms of medication adherence were reported during interviews, along with 27 drivers of non-adherence, all of which were incorporated into a conceptual model. Participants reported skipping medication doses (n=36/57; 63.2%) or taking medication later in the day than prescribed (n=29/57; 50.9%). Common drivers of non-adherence included forgetfulness (n=35/57; 61.4%), being out of the usual routine (n=31/57; 54.4%) and being busy (n=22/57; 38.6%). US participants were more likely to report non-adherence due to low perceived efficacy (n=6/21, 28.6%) and cost (n=5/21, 23.8%) than German (n=1/18, 5.6%; n=0/18, 0.0%) or Spanish (n=2/18, 11.1%; n=1/18, 5.6%) participants.
Conclusion
Findings highlight the diverse forms and drivers of medication non-adherence, informing the development of a comprehensive conceptual model of medication adherence. The conceptual model builds on and advances previous models of medication adherence and can be used by healthcare professionals to understand and interpret barriers to medication adherence and how best to support patients in taking their medication as intended.
Plain Language Summary
Medication adherence is the extent to which a patient takes their medication as prescribed. This paper describes a literature review and concept elicitation interviews to identify forms and drivers of medication adherence across a diverse sample of participants. Forms of non-adherence identified included: deviating from the prescription, skipping a dose, taking a different amount, and taking medication at a different time. Behaviours and drivers can vary by condition, treatment modality, and dosing schedule.
This research highlights the variation in the prevalence of medication non-adherence, and the different forms and drivers of non-adherence, based on individuals’ demographic and clinical characteristics. The conceptual model developed advances previous models of medication adherence and may support healthcare professionals in the management of patients and how they can be supported to take medication as intended. The research ultimately informed the development of the Adelphi Adherence Questionnaire (ADAQ©), a novel generic patient-reported outcome measure.
Data Sharing Statement
Transcripts from the interviews are not able to be shared for data protection purposes.
Acknowledgments
We would like to acknowledge all participants of the study and thank them for their valuable contribution.
Disclosure
SB, RA, VH, and JP are employees of Adelphi Group Ltd, and EE and LM were employees of Adelphi Group Ltd when the research was conducted. RR, NR, and KK were contracted by Adelphi Group Ltd to provide clinical advice throughout this project. KK reports grants from AstraZeneca, personal fees from AstraZeneca, grants from Novartis, personal fees from Novartis, personal fees from Sanofi-Aventis, grants from Sanofi-Aventis, grants from Lilly, personal fees from Lilly, grants from Merck Sharp & Dohme, personal fees from Merck Sharp & Dohme, personal fees from Boehringer Ingelheim, grants from Boehringer Ingelheim, personal fees from Bayer, personal fees from Abbott, personal fees from Amgen, personal fees from Napp, personal fees from Roche, grants from Servier, personal fees from Servier, Study Lead for UK Oramed Pharmaceuticals, Study Lead for UK Applied Therapeutics, during the conduct of the study and is supported by the National Institute for Health Research (NIHR) Applied Research Collaboration East Midlands and the NIHR Leicester Biomedical Research Centre. NR reports grants and personal fees from Boehringer Ingelheim, Novartis, Pfizer, GlaxoSmithKline and personal fees from MSD, AstraZeneca, Chiesi, Sanofi and Zambon. RR reports grants from the National Institutes of Health and the Patient-Centered Outcomes Research Institute. The authors report no other conflicts of interest in this work.