Cognitive Training for Post-Acute Traumatic Brain Injury: A Systematic Review and Meta-Analysis.

To quantitatively aggregate effects of cognitive training (CT) on cognitive and functional outcome measures in patients with traumatic brain injury (TBI) more than 12-months post-injury. We systematically searched six databases for non-randomized and randomized controlled trials of CT in TBI patients at least 12-months post-injury reporting cognitive and/or functional outcomes. Efficacy was measured as standardized mean difference (Hedges' ) of post-training change. We investigated heterogeneity across studies using subgroup analyses and meta-regressions. Fourteen studies encompassing 575 patients were included. The effect of CT on overall cognition was small and statistically significant ( = 0.22, 95%CI 0.05 to 0.38; = 0.01), with low heterogeneity ( = 11.71%) and no evidence of publication bias. A moderate effect size was found for overall functional outcomes ( = 0.32, 95%CI 0.08 to 0.57, = 0.01) with low heterogeneity ( = 14.27%) and possible publication bias. Statistically significant effects were also found only for executive function ( = 0.20, 95%CI 0.02 to 0.39, = 0.03) and verbal memory ( = 0.32, 95%CI 0.14 to 0.50, < 0.01). Despite limited studies in this field, this meta-analysis indicates that CT is modestly effective in improving cognitive and functional outcomes in patients with post-acute TBI and should therefore play a more significant role in TBI rehabilitation.