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UBC Theses and Dissertations

Adherence in e-health interventions for substance use and the factors influencing it : systematic review, meta-analysis, and meta-regression Shams, Farhud


Background: Globally, around 36 million people have a drug use disorder, while only one in eight receive the treatment they need. Research and development of e-health interventions targeting substance use have been becoming increasingly popular in the last decade, due to their unique ability to reach wide populations. Low exposure of participants and adherence to interventions and their content has been a widely dis-cussed issue in the literature of e-health interventions. Adherence in e-health interven-tions is defined as “the degree to which individuals experience the content of the Inter-net intervention”. Although adherence may be an important factor in determining the effectiveness of an intervention targeting substance use, not many studies have been specifically focusing on this aspect. Objectives: In this review, we set out to analyze the data on adherence from studies on e-health interventions targeting substance use and assess four predictors of ad-herence. The four factors that were hypothesized to predict adherence were guidance, blended treatment, recruitment, and treatment duration. Methods: A systematic review of published literature from 2009-2020 was conducted and data on two adherence measures and predictors of adherence were extracted. The two adherence measures were (1) the mean proportion of modules completed across the intervention group and (2) the proportion of participants that completed all modules. Results: The overall pooled adherence rate was 0.60 (95%-CI: 0.52-0.67) for the mean proportion of modules completed across 30 intervention arms and 0.47 (95%-CI: 0.35-0.59) for the proportion of participants that completed all modules across nine in-tervention arms. Four meta-regression models assessed each covariate. The three variables guidance, blended treatment, and recruitment were statistically significant predictors of adherence. Treatment duration was not a significant predictor of adher-ence. Conclusion: The results of the present review suggest that there may be some predic-tors of adherence that should be considered in further investigations and develop-ments of interventions. Future studies should put a greater emphasis on reporting ad-herence, as that would allow for more accurate meta-analyses and predictor models to help improve understanding of adherence and its predictors.

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