Format

Send to

Choose Destination
BMJ Open. 2015 Apr 2;5(4):e005247. doi: 10.1136/bmjopen-2014-005247.

Do cognitive interventions improve general cognition in dementia? A meta-analysis and meta-regression.

Author information

1
Department of Old Age Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.

Abstract

OBJECTIVES:

To review the efficacy of cognitive interventions on improving general cognition in dementia.

METHOD:

Online literature databases and trial registers, previous systematic reviews and leading journals were searched for relevant randomised controlled trials. A systematic review, random-effects meta-analyses and meta-regression were conducted. Cognitive interventions were categorised as: cognitive stimulation (CS), involving a range of social and cognitive activities to stimulate multiple cognitive domains; cognitive training (CT), involving repeated practice of standardised tasks targeting a specific cognitive function; cognitive rehabilitation (CR), which takes a person-centred approach to target impaired function; or mixed  CT and stimulation (MCTS). Separate analyses were conducted for general cognitive outcome measures and for studies using 'active' (designed to control for non-specific therapeutic effects) and non-active (minimal or no intervention) control groups.

RESULTS:

33 studies were included. Significant positive effect sizes (Hedges’ g) were found for CS with the mini-mental state examination (MMSE) (g=0.51, 95% CI 0.35 to 0.66; p<0.001) compared to non-active controls and (g=0.35, 95% CI 0.06 to 0.64; p=0.019) compared to active controls. Significant benefit was also seen with the Alzheimer's disease Assessment Scale-Cognition (ADAS-Cog) (g=-0.26, 95% CI -0.445 to -0.08; p=0.005). There was no evidence that CT or MCTS produced significant improvements on general cognition outcomes and not enough CR studies for meta-analysis. The lowest accepted minimum clinically important difference was reached in 11/17 CS studies for the MMSE, but only 2/9 studies for the ADAS-Cog. Additionally, 95% prediction intervals suggested that although statistically significant, CS may not lead to benefits on the ADAS-Cog in all clinical settings.

CONCLUSIONS:

CS improves scores on MMSE and ADAS-Cog in dementia, but benefits on the ADAS-Cog are generally not clinically significant and difficulties with blinding of patients and use of adequate placebo controls make comparison with the results of dementia drug treatments problematic.

KEYWORDS:

GERIATRIC MEDICINE

PMID:
25838501
PMCID:
PMC4390716
DOI:
10.1136/bmjopen-2014-005247
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center