Addressing cognitive impairment following stroke: systematic review and meta-analysis of non-randomised controlled studies of psychological interventions

Objective Cognitive impairment is a pervasive outcome of stroke, reported in over half of patients 6 months post-stroke and is associated with increased disability and a poorer quality of life. Despite the prevalence of post-stroke cognitive impairment, the efficacy of existing psychological interventions for the rehabilitation of cognitive impairment following stroke has yet to be established. The aim of this study is to identify psychological interventions from non-randomised studies that intended to improve post-stroke cognitive function and establish their efficacy. Design Systematic review and meta-analysis of non-randomised studies of psychological interventions addressing post-stroke cognitive impairment. Data sources Electronic searches were performed in the Pubmed, EMBASE and PsycINFO databases, the search dating from inception to February 2017. Eligibility criteria All non-randomised controlled studies and quasi-randomised controlled trials examining psychological interventions to improve cognitive function following stroke were included, such as feasibility studies, pilot studies, experimental studies, and quasi-experimental studies. The primary outcome was cognitive function. The prespecified secondary outcomes were functional abilities in daily life and quality of life. Methods The current meta-analyses combined the findings of seven controlled studies, examining the efficacy of psychological interventions compared with treatment-as-usual controls or active controls, and 13 one-group pre-post studies. Results Results indicated an overall small effect on cognition across the controlled studies (Hedges' g=0.38, 95% CI=0.06 to 0.7) and a moderate effect on cognition across the one-group pre-post studies (Hedges' g=0.51, 95% CI=0.3 to 0.73). Specific cognitive domains, such as memory and attention also demonstrated a benefit of psychological interventions. Conclusions This review provides support for the potential of psychological interventions to improve overall cognitive function post-stroke. Limitations of the study, in terms of risk of bias and quality of included studies, and future research directions are explored.