[Is dementia preventable through intensive vascular care? The preDIVA trial]

To assess whether intensive vascular care in GP practices can prevent dementia in a population of community-dwelling older people.

This pragmatic cluster-randomised open-label study (ISRCTN29711771) was conducted in persons aged 70-78 years who were registered with Dutch GP practices. The only exclusion criteria were a diagnosis of dementia and limited life expectancy. Practices were randomly assigned to an intervention arm or a control arm. Participants in the interventional arm underwent a cardiovascular check-up every 4 months for six years by a practice nurse. Primary outcomes were cumulative incidence of dementia and functional limitations. Main secondary outcomes were the incidence of cardiovascular disease and mortality.

Between June 2006 and March 2009, 116 GP practices (3526 participants) were recruited and randomly assigned: 63 (1890 participants) 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. In this period, dementia was diagnosed in 121/1853 (6.5%) participants in the intervention group and in 112/1601 (7.0%) participants in the control group. This difference was not significant (hazard ratio 0.92, 95% CI 0.71-1.19). No differences were found with regard to functional decline, incident cardiovascular disease and mortality.

Long-term intensive vascular care for community-dwelling elderly patients, provided in a primary care setting, does not result in a reduced incidence of dementia, functional limitations or mortality. There is, however, possibly an effect in elderly patients with untreated or sub-optimally treated hypertension; this warrants further research.