Objective To synthesise findings from randomised controlled trials (RCTs) of interventions aimed at increasing medication adherence in individuals with type 2 diabetes (T2DM) and/or cardiovascular disease (CVD). And, in a novel approach, to compare the intervention effect of studies which were categorised as being more pragmatic or more explanatory using the Pragmatic-Explanatory Continuum Indicator Summary-2 (PRECIS-2) tool, to identify whether study design affects outcomes. As explanatory trials are typically held under controlled conditions, findings from such trials may not be relatable to real-world clinical practice. In comparison, pragmatic trials are designed to replicate real-world conditions and therefore findings are more likely to represent those found if the intervention were to be implemented in routine care.
Design Systematic review and meta-analysis.
Data sources Ovid Medline, Ovid Embase, Web of Science and CINAHL from 1 January 2013 to 31 December 2018.
Eligibility criteria for selecting studies RCTs lasting ≥3 months (90 days), involving ≥200 patients in the analysis, with either established CVD and/or T2DM and which measured medication adherence. From 4403 citations, 103 proceeded to full text review. Studies published in any language other than English and conference abstracts were excluded.
Main outcome measure Change in medication adherence.
Results Of 4403 records identified, 34 studies were considered eligible, of which 28, including 30 861 participants, contained comparable outcome data for inclusion in the meta-analysis. Overall interventions were associated with an increase in medication adherence (OR 1.57 (95% CI: 1.33 to 1.84), p<0.001; standardised mean difference 0.24 (95% CI: −0.10 to 0.59) p=0.101). The effectiveness of interventions did not differ significantly between studies considered pragmatic versus explanatory (p=0.598), but did differ by intervention type, with studies that included a multifaceted rather than a single-faceted intervention having a more significant effect (p=0.010). The analysis used random effect models and used the revised Cochrane Risk of Bias Tool to assess study quality.
Conclusions In this meta-analysis, interventions were associated with a significant increase in medication adherence. Overall multifaceted interventions which included an element of education alongside regular patient contact or follow-up showed the most promise. Effectiveness of interventions between pragmatic and explanatory trials was comparable, suggesting that findings can be transferred from idealised to real-word conditions.
PROSPERO registration number CRD42017059460.
- diabetes & endocrinology
- diabetes & endocrinology
This is an open access article distributed in accordance with the Creative Commons Attribution 4.0 Unported (CC BY 4.0) license, which permits others to copy, redistribute, remix, transform and build upon this work for any purpose, provided the original work is properly cited, a link to the licence is given, and indication of whether changes were made. See: https://creativecommons.org/licenses/by/4.0/.
Statistics from Altmetric.com
CF and CG contributed equally.
Contributors CF developed the study protocol, carried out the scientific literature search, screened and extracted data, undertook PRECIS-2 scoring, quality assessed studies, interpreted the results and developed the first draft of the manuscript. CG quality assessed studies, interpreted the results, undertook data checking, PRECIS-2 scoring, performed all statistical analysis and contributed to the development of the manuscript. SS assisted with the design of the review and provided intellectual content to the drafted manuscript. DK assisted with the design of the review, applied for funding and assisted with protocol development. EI screened articles for inclusion in the review. MJD provided intellectual content to the drafted manuscript. PP and PG assisted with the design of the review. KK had the concept of the study, applied for funding, assisted with protocol development and provided intellectual oversight on the development of the manuscript. KK accepts full responsibility for the conduct of the study, has access to the data and controlled the decision to publish. KK as the corresponding author attests that all listed authors meet authorship criteria and that no others meeting the criteria have been omitted.
Funding The authors received funding from the NIHR CLAHRC—EM and the Leicester Biomedical Research Centre.
Disclaimer The views expressed are those of the authors and not necessarily those of the National Health Service, the NIHR or the Department of Health.
Competing interests MJD reports grants from Novo Nordisk, grants from Sanofi-Aventis, grants from Lilly, grants from Boehringer Ingelheim, grants from Janssen, personal fees from Novo Nordisk, personal fees from Sanofi-Aventis, personal fees from Lilly, personal fees from Merck Sharp & Dohme, personal fees from Boehringer Ingelheim, personal fees from AstraZeneca, personal fees from Janssen, personal fees from Servier, personal fees from Mitsubishi Tanabe Pharma, personal fees from Takeda Pharmaceuticals International, outside the submitted work. KK reports personal fees from Amgen, personal fees from AstraZeneca, personal fees from Bayer, personal fees from NAPP, personal fees from Lilly, personal fees from Merck Sharp & Dohme, personal fees from Novartis, personal fees from Novo Nordisk, personal fees from Roche, personal fees from Berlin-Chemie AG/Menarini Group, personal fees from Sanofi-Aventis, personal fees from Servier, personal fees from Boehringer Ingelheim, grants from Pfizer, grants from Boehringer Ingelheim, grants from AstraZeneca, grants from Novartis, grants from Novo Nordisk, grants from Sanofi-Aventis, grants from Lilly, grants from Merck Sharp & Dohme, grants from Servier, outside the submitted work.
Patient and public involvement Patient and public involvement (PPI) was undertaken prior to the development of the review to obtain an understanding of patient reasons for non-adherence. A number of themes were identified and included side effects of drugs and poor explanations from healthcare professionals about prescribed drugs. Following the completion of the review, alongside the views and opinions expressed during the PPI, the study team aim to develop a toolbox and education programme to support medication adherence. A second focus group is planned comprising health professionals, with the objective of gathering their perspectives on how to promote the 'toolbox' for general utilisation in clinical practice and how best to disseminate and mainstream the toolbox of interventions.
Patient consent for publication Not required.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement Data are available on reasonable request. Data are available on reasonable request from the corresponding author.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.