Multidomain interventions for the prevention of dementia and cognitive decline: A Cochrane systematic review and meta‐analysis

Abstract

AbstractBackgroundWith no effective pharmacological therapies, risk factor modification may be a suitable intervention for dementia prevention. To date, no single‐domain intervention has convincingly shown to reduce the risk of developing dementia. Targeting more than one risk factor might have additive or even synergistic effects. In this Cochrane systematic review, we investigated the effect of multidomain intervention studies on the prevention of dementia and cognitive declineMethodWe searched ALOIS (the Cochrane Dementia and Cognitive Improvement Group's register), MEDLINE, Embase, PsycINFO, CINAHL, Web of Science Core Collection, LILACS, and ClinicalTrials.gov from origin to April 2020. We included randomized controlled trials (RCTs) targeting at least two dementia risk factors simultaneously, with >400 participants and >12 months of follow‐up. Data were pooled using random‐effect models. This abstract is based on a pre‐peer review version of a Cochrane Review (protocol DOI: 10.1002/14651858.CD013572).ResultThe search identified 13.039 studies. Nine RCTs fulfilled the inclusion criteria and could be included in the review and meta‐analysis; two studies reported incident dementia as outcome, all nine studies reported a measure for cognitive decline. Overall pooled risk ratio (RR) for dementia was 0.94 (95% confidence interval (CI) 0.76‐1.18, I2<10%) and standardised mean difference (SMD) for cognitive decline measured with a neurological test battery (NTB) 0.03 (95% CI 0.01‐0.06, I2<10%). SMD in mini‐mental state examination (MMSE) score was 0.00 (95% CI ‐0.03‐0.04). Subgroup analyses suggested modest favourable outcomes on cognitive decline (NTB) for participants with worse baseline cognitive status (SMD 0.06 (0.01‐ 0.11) for low baseline MMSE vs. SMD 0.01 (‐0.01‐0.04) for high baseline MMSE), though this difference was not significant (p=0.12). There was no difference between groups with respect to adverse events (mortality, cardiovascular disease and stroke). The overall quality of evidence was moderate to high.ConclusionMultidomain interventions did not improve the overall risk of dementia. There was a modest effect on cognitive decline measured with a NTB, though this effect was not convincingly supported by other cognitive assessment scores. Future research in populations at increased risk could have important implications for dementia prevention strategies.