Memory-focused interventions for people with cognitive disorders: A systematic review and meta-analysis of randomized controlled studies

Background: A better understanding of people with cognitive disorders improves performance on memory tasks through memory-focused interventions are needed. Objectives: The purpose of this study was to assess the effect of memoryfocused interventions on cognitive disorders through a meta-analysis. Design: Systematic review and meta-analysis. Data sources: The online electronic databases PubMed, the Cochrane Library, Ovid-Medline, CINHAL, PsycINFO, Ageline, and Embase (up to May 2017) were used in this study. No language restriction was applied to the search. Review methods: Objective memory (learning and memory function, immediate recall, delayed recall, and recognition) was the primary indicator and subjective memory performance, global cognitive function, and depression were the secondary indicators. The Hedges' g of change, subgroup analyses, and meta-regression were analyzed on the basis of the characteristics of people with cognitive disorders. Results: A total of 27 studies (2177 participants, mean age = 75.80) reporting RCTs were included in the meta analysis. The results indicated a medium-to-large effect of memory-focused interventions on learning and memory function (Hedges' g = 0.62) and subjective memory performance (Hedges' g = 0.67), a small-to-medium effect on delayed recall and depression, and a small effect on immediate recall and global cognitive function (all p < 0.05) compared with the control. Subgroup analysis and meta-regression indicated that the effects on learning and memory function were more profound in the format of memory training, individual training, shorter treatment duration, and more than eight treatment sessions, and the effect size indicated the MMSE score was the most crucial indicator (beta = -0.06, p = 0.04). Conclusions: This is first comprehensive meta-analysis of special memory domains in people with cognitive disorders. The results revealed that memory-focused interventions effectively improved memory-related performance in people with cognitive disorders. An appropriately designed intervention can effectively improve memory function, reduce disability progression, and improve mood state in people with cognitive disorders. Additional randomized controlled trials including measures of recognition, global cognitive function, and depression should be conducted and analyzed.