Adherence to cognitive training in patients with mild cognitive impairment and dementia: A systematic review and meta-analysis.

This systematic review and meta-analysis evaluated adherence to cognitive training among patients with mild cognitive impairment (MCI) and dementia. PubMed, Web of Science, Scopus, the Cochrane Library, and Embase were searched from inception to 12 August 2026. Study quality was assessed using the Cochrane Risk of Bias 2 tool or the JBI Quality Assessment Tool. This review included 32 studies. A random-effects meta-analysis of 20 studies yielded a pooled adherence rate of 81% (95% confidence interval: 72-89%; I2 = 99.23%, P < 0.001). Definitions of adherence were reported in 23 studies and covered attendance, completion, and training dose, commonly measured using session-based or participant-based proportions. The descriptive synthesis suggested that adherence varied according to intervention duration and setting. Leave-one-out sensitivity analyses yielded pooled rates of 80-84%, supporting the numerical stability of the primary estimate despite persistent heterogeneity. Cognitive training showed relatively high adherence among patients with MCI and dementia. Standardized adherence assessment and reporting are needed to support implementation in clinical and community settings.Trial registration: ClinicalTrials.gov identifier: NCT06499272..