Research in context
Systematic review
We searched ClinicalTrials.gov and WHO's International Clinical Trial Registry Platform up to Jan 31, 2015, to identify larger multidomain randomised controlled trials. Search terms were “prevention of dementia OR prevention of Alzheimer disease”. Further selection criteria included primary outcome cognitive impairment or dementia; at least two combined interventions (eg, physical exercise, cognitive training, social activities, dietary intervention, drug or dietary supplement); age 40 years or older; duration at least 1 year; and size 500 participants or greater. We based criteria on the 2010 National Institutes of Health Evidence Report on Preventing Alzheimer's Disease and Cognitive Decline. We identified two ongoing randomised controlled trials, the Multidomain Alzheimer Preventive Trial (MAPT; NCT00672685) and Prevention of Dementia by Intensive Vascular Care (Pre-DIVA; ISRCTN29711771). Results are not yet available.
Added value of the study
To our knowledge, the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) is the first large, longer-term, and methodologically robust trial showing that a multidomain intervention can improve or maintain cognitive functioning and reduce the risk of cognitive decline among older at-risk individuals. FINGER targeted the at-risk segment of the general elderly population, not patients in a clinical setting. Results are thus most appropriately interpreted in a public health context, where small long-term changes can have large effects. The FINGER extended follow-up will provide further knowledge about intervention effects on incidence of dementia and Alzheimer's disease.
Interpretation
After many negative dementia trials, the focus has shifted to presymptomatic and predementia disease stages and at-risk states when intervention might not be too late. In these early stages, no other trials have so far provided references for expected cognitive effects, and these references cannot be simply extrapolated from dementia trials. FINGER provides a first reference, and also a novel and pragmatic model, for dementia prevention trials that can be tested and adapted in various other settings and populations.