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Published on: August 1, 2019
A measurement framework for adherence in patient decision aid trials applied in a systematic review subanalysis
Logan Trenaman1, Anna Selva2, Sophie Desroches3
1School of Population and Public Health, University of British Columbia, Vancouver V6T 1Z3, Canada; Centre for Clinical Epidemiology and Evaluation, Vancouver Coastal Health Research Institute, 7th Floor, 828 West 10th Avenue, Vancouver V5Z 1M9, Canada; Centre for Health Evaluation and Outcome Sciences, 588 - 1081 Burrard Street, St. Paul's Hospital, Vancouver V6Z 1Y6, Canada; Ottawa Hospital Research Institute, 725 Parkdale Avenue, Ottawa K1Y 4E9, Canada.
Objective:
To explore how studies of decision aids conceptualize and measure adherence and to evaluate the effect of patient decision aids on adherence.
Study Design And Setting:
A subanalysis of adherence studies included in the 2014 Cochrane review on patient decision aids. An adherence framework for decision aid trials is presented which includes two types of adherence: "adherence to choice" and "adherence to treatment." Included studies were classified based on the adherence framework, and their impact on adherence was assessed.
Results:
Thirteen trials involving 2,115 patients were included. Of these 13, eight measured "adherence to choice" and 10 measured "adherence to treatment." There was considerable heterogeneity in how adherence was measured, with studies varying in whether they considered baseline choice, follow-up choice, or neither, and whether they presented separate or aggregated adherence measures. No studies measuring "adherence to choice" reported significant differences between the decision aid and comparator, whereas four studies measuring adherence to treatment reported a statistically significant difference between the decision aid and comparator, with three favoring the decision aid arm.
Conclusions:
The adherence framework provided insight into important measurement factors. There remains considerable heterogeneity in measures of adherence which makes it difficult to draw conclusions.
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