Abstract
IMPORTANCE: Although there is substantial evidence to suggest the health benefits of acceptance and commitment therapy (ACT) among informal caregivers of people with chronic health conditions, the great variation in intervention designs among published studies limits its application. OBJECTIVES: To identify intervention characteristics of ACT that are associated with improved psychological health and to assess the acceptability of ACT among informal caregivers. DATA SOURCES: Seven English- and 3 Chinese-language databases without limits on publication dates, the reference lists of previous reviews, and gray literature were searched up to February 2023. STUDY SELECTION: Randomized clinical trials comparing the effect of ACT vs control groups on improving psychological health among informal caregivers. DATA EXTRACTION AND SYNTHESIS: Two reviewers independently screened searched records and extracted data from eligible studies. Random-effects meta-analysis and mixed-effects metaregression were performed. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline was followed. MAIN OUTCOMES AND MEASURES: Psychological health outcomes (eg, depressive symptoms) measured by valid measurements and the acceptability of ACT based on identified parameters. RESULTS: A total of 29 studies with 2010 participants, published between 2015 and 2023, were identified. ACT showed moderate to large effect sizes for improving psychological health at postintervention assessments (Hedges g range, -0.55 [95% CI, -0.98 to -0.12] to -1.14 [95% CI, -1.83 to -0.45]) and at 1-to-3-month and 4-to-6-month follow-ups (Hedges g range, -0.47 [95% CI, -0.69 to -0.25] to -1.29 [95% CI, -2.33 to -0.24]). Multivariable metaregression analysis regarding intervention characteristics found that ACT delivered in a mixed individual- and group-based format, face-to-face, or through more intervention sessions was associated with greater improvements for experiential avoidance (face-to-face: β = -1.170 [95% CI, -2.020 to -0.319]; number of sessions: β = -0.242 [95% CI, -0.353 to -0.130]), depressive symptoms (mixed delivery format: β = -2.583 [95% CI, -4.845 to -0.321]; face-to-face: β = -1.555 [95% CI, -3.002 to -0.108]), or anxiety symptoms (face-to-face: β = -1.241 [95% CI, -2.337 to -0.146]). In general, ACT had low attrition rates (11%), and participants' adherence (51%-80%) and satisfactory ratings (72%-95%) lend support to its acceptability. CONCLUSIONS AND RELEVANCE: This systematic review and meta-analysis found that ACT was consistently associated with improvements in psychological health, supporting its application to improve informal care for chronic disease management. This review provides specific details on the design parameters of ACT for achieving greater efficacy.