BACKGROUND: Cardiovascular risk factors are associated with an increased risk of 
dementia. We assessed whether a multidomain intervention targeting these factors 
can prevent dementia in a population of community-dwelling older people.
METHODS: In this open-label, cluster-randomised controlled trial, we recruited 
individuals aged 70-78 years through participating general practices in the 
Netherlands. General practices within each health-care centre were randomly 
assigned (1:1), via a computer-generated randomisation sequence, to either a 
6-year nurse-led, multidomain cardiovascular intervention or control (usual 
care). The primary outcomes were cumulative incidence of dementia and disability 
score (Academic Medical Center Linear Disability Score [ALDS]) at 6 years of 
follow-up. The main secondary outcomes were incident cardiovascular disease and 
mortality. Outcome assessors were masked to group assignment. Analyses included 
all participants with available outcome data. This trial is registered with 
ISRCTN, number ISRCTN29711771.
FINDINGS: Between June 7, 2006, and March 12, 2009, 116 general practices (3526 
participants) within 26 health-care centres were recruited and randomly 
assigned: 63 (1890 participants) were assigned to the intervention group and 53 
(1636 participants) to the control group. Primary outcome data were obtained for 
3454 (98%) participants; median follow-up was 6·7 years (21 341 person-years). 
Dementia developed in 121 (7%) of 1853 participants in the intervention group 
and in 112 (7%) of 1601 participants in the control group (hazard ratio [HR] 
0·92, 95% CI 0·71-1·19; p=0·54). Mean ALDS scores measured during follow-up did 
not differ between groups (85·7 [SD 6·8] in the intervention group and 85·7 
[7·1] in the control group; adjusted mean difference -0·02, 95% CI -0·38 to 
0·42; p=0·93). 309 (16%) of 1885 participants died in the intervention group, 
compared with 269 (16%) of 1634 participants in the control group (HR 0·98, 95% 
CI 0·80-1·18; p=0·81). Incident cardiovascular disease did not differ between 
groups (273 [19%] of 1469 participants in the intervention group and 228 [17%] 
of 1307 participants in the control group; HR 1·06, 95% CI 0·86-1·31; p=0·57).
INTERPRETATION: A nurse-led, multidomain intervention did not result in a 
reduced incidence of all-cause dementia in an unselected population of older 
people. This absence of effect might have been caused by modest baseline 
cardiovascular risks and high standards of usual care. Future studies should 
assess the efficacy of such interventions in selected populations.
FUNDING: Dutch Ministry of Health, Welfare and Sport; Dutch Innovation Fund of 
Collaborative Health Insurances; and Netherlands Organisation for Health 
Research and Development.