Objectives: To provide quantitative information about the overall effectiveness of adherence interventions to improve adherence and health outcomes for children with chronic illnesses. To evaluate statistically the potential moderators.
Methods: A meta-analysis was performed on 71 adherence intervention studies.
Results: Weighted-mean effect size (ES) across all the adherence outcomes for group design studies was in the medium range (mean d = 0.58) and for single-subject design studies was in the large range (mean d = 1.44). The weighted mean ES across all health outcome measures for studies using group designs was in the medium range (mean d = 0.40) and for studies using single-subject designs was in the large range (mean d = 0.74).
Conclusions: Adherence interventions for children with chronic illnesses effectively increase adherence and result in some positive health benefits. Intervention and methodological variables had significant impact on ESs. High levels of heterogeneity characterized the data.