Memory training interventions for older adults: a meta-analysis

Abstract

A systematic review and meta-analysis of memory training research was conducted to characterize the effect of memory strategies on memory performance among cognitively intact, community-dwelling older adults, and to identify characteristics of individuals and of programs associated with improved memory. The review identified 402 publications, of which 35 studies met criteria for inclusion. The overall effect size estimate, representing the mean standardized difference in pre-post change between memory-trained and control groups, was 0.31 standard deviations (SD; 95% confidence interval (CI): 0.22, 0.39). The pre-post training effect for memory-trained interventions was 0.43 SD (95% CI: 0.29, 0.57) and the practice effect for control groups was 0.06 SD (95% CI: 0.05, 0.16). Among 10 distinct memory strategies identified in studies, meta-analytic methods revealed that training multiple strategies was associated with larger training gains (p=0.04), although this association did not reach statistical significance after adjusting for multiple comparisons. Treatment gains among memory-trained individuals were not better after training in any particular strategy, or by the average age of participants, session length, or type of control condition. These findings can inform the design of future memory training programs for older adults.

Figure 1. Forest Plot of Effect Sizes

Legend. Effect sizes representing retest-adjusted standardized differences (in standard deviation units) in pre-post memory change between memory-trained and control groups are graphed. Training and control group-specific effect sizes are also provided in columns at right. Control effect sizes are not shown for two studies because the same control group was used to compare against more than one memory training intervention. 95% CI: 95% confidence interval.

Figure 2. Distribution of Study Effect Sizes by Training Status

Legend. Effect sizes represent standardized pre-post changes (in standard deviation units) in memory for memory-trained and control groups.

Figure 3. Funnel Plot of Effect Sizes with Pseudo 95% Confidence Intervals

Legend. Effect sizes represent retest-adjusted standardized differences (in standard deviation units) in pre-post memory change between memory-trained and control groups. Diagonal dotted lines represent 95% confidence intervals of the expected distribution of studies around the mean memory effect size estimate for each standard error on the ordinate, assuming no between-study heterogeneity. They are referred to as pseudo because the lines are not strict confidence limits.