Occupational therapy for cognitive impairment in stroke patients.

Abstract

BACKGROUND: Cognitive impairment is a frequent consequence of stroke and can impact on a person's ability to perform everyday activities. Occupational therapists use a range of interventions when working with people who have cognitive impairment poststroke. This is an update of a Cochrane Review published in 2010.

OBJECTIVES: To assess the impact of occupational therapy on activities of daily living (ADL), both basic and instrumental, global cognitive function, and specific cognitive abilities in people who have cognitive impairment following a stroke.

SEARCH METHODS: We searched the Cochrane Stroke Group Trials Register, CENTRAL, MEDLINE, Embase, four other databases (all last searched September 2020), trial registries, and reference lists.

SELECTION CRITERIA: We included randomised and quasi-randomised controlled trials that evaluated an intervention for adults with clinically defined stroke and confirmed cognitive impairment. The intervention needed either to be provided by an occupational therapist or considered within the scope of occupational therapy practice as defined in the review. We excluded studies focusing on apraxia or perceptual impairments or virtual reality interventions as these are covered by other Cochrane Reviews. The primary outcome was basic activities of daily living (BADL) such as dressing, feeding, and bathing. Secondary outcomes were instrumental ADL (IADL) (e.g. shopping and meal preparation), community integration and participation, global cognitive function and specific cognitive abilities (including attention, memory, executive function, or a combination of these), and subdomains of these abilities. We included both observed and self-reported outcome measures.

DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies that met the inclusion criteria, extracted data, and assessed the certainty of the evidence. A third review author moderated disagreements if consensus was not reached. We contacted trial authors for additional information and data, where available. We assessed the certainty of key outcomes using GRADE.  MAIN RESULTS: We included 24 trials from 11 countries involving 1142 (analysed) participants (two weeks to eight years since stroke onset). This update includes 23 new trials in addition to the one study included in the previous version. Most were parallel randomised controlled trials except for one cross-over trial and one with a two-by-two factorial design. Most studies had sample sizes under 50 participants. Twenty studies involved a remediation approach to cognitive rehabilitation, particularly using computer-based interventions. The other four involved a compensatory and adaptive approach. The length of interventions ranged from 10 days to 18 weeks, with a mean total length of 19 hours. Control groups mostly received usual rehabilitation or occupational therapy care, with a few receiving an attention control that was comparable to usual care; two had no intervention (i.e. a waiting list). Apart from high risk of performance bias for all but one of the studies, the risk of bias for other aspects was mostly low or unclear.  For the primary outcome of BADL, meta-analysis found a small effect on completion of the intervention with a mean difference (MD) of 2.26 on the Functional Independence Measure (FIM) (95% confidence interval (CI) 0.17 to 4.22; P = 0.03, I2 = 0%; 6 studies, 336 participants; low-certainty evidence). Therefore, on average, BADL improved by 2.26 points on the FIM that ranges from 18 (total assist) to 126 (complete independence). On follow-up, there was insufficient evidence of an effect at three months (MD 10.00, 95% CI -0.54 to 20.55; P = 0.06, I2 = 53%; 2 studies, 73 participants; low-certainty evidence), but evidence of an effect at six months (MD 11.38, 95% CI 1.62 to 21.14, I2 = 12%; 2 studies, 73 participants; low-certainty evidence). These differences are below 22 points which is the established minimal clinically important difference (MCID) for the FIM for people with stroke. For IADL, the evidence is very uncertain about an effect (standardised mean difference (SMD) 0.94, 95% CI 0.41 to 1.47; P = 0.0005, I2 = 98%; 2 studies, 88 participants). For community integration, we found insufficient evidence of an effect (SMD 0.09, 95% CI -0.35 to 0.54; P = 0.68, I2 = 0%; 2 studies, 78 participants). There was an improvement of clinical importance in global cognitive functional performance after the intervention (SMD 0.35, 95% CI 0.16 to 0.54; P = 0.0004, I2 = 0%; 9 studies, 432 participants; low-certainty evidence), equating to 1.63 points on the Montreal Cognitive Assessment (MoCA) (95% CI 0.75 to 2.52), which exceeds the anchor-based MCID of the MoCA for stroke rehabilitation patients of 1.22. We found some effect for attention overall (SMD -0.31, 95% CI -0.47 to -0.15; P = 0.0002, I2 = 20%; 13 studies, 620 participants; low-certainty evidence), equating to a difference of 17.31 seconds (95% CI 8.38 to 26.24), and for executive functional performance overall (SMD 0.49, 95% CI 0.31 to 0.66; P < 0.00001, I2 = 74%; 11 studies, 550 participants; very low-certainty evidence), equating to 1.41 points on the Frontal Assessment Battery (range: 0-18). Of the cognitive subdomains, we found evidence of effect of possible clinical importance, immediately after intervention, for sustained visual attention (moderate certainty) equating to 15.63 seconds, for working memory (low certainty) equating to 59.9 seconds, and thinking flexibly (low certainty), compared to control.

AUTHORS' CONCLUSIONS: The effectiveness of occupational therapy for cognitive impairment poststroke remains unclear. Occupational therapy may result in little to no clinical difference in BADL immediately after intervention and at three and six months' follow-up. Occupational therapy may slightly improve global cognitive performance of a clinically important difference immediately after intervention, likely improves sustained visual attention slightly, and may slightly increase working memory and flexible thinking after intervention. There is evidence of low or very low certainty or insufficient evidence for effect on other cognitive domains, IADL, and community integration and participation.  Given the low certainty of much of the evidence in our review, more research is needed to support or refute the effectiveness of occupational therapy for cognitive impairment after stroke. Future trials need improved methodology to address issues including risk of bias and to better report the outcome measures and interventions used.