The possibility of either AD (OR 1.11, 95% CI 1.02-1.20, p<0.01) or vascular co-morbidities (OR 1.46, 95% CI 1.30-1.64, p<0.01) is more likely with increasing age. Individual CVD lesions frequently occur when AD or vascular risk factors are present (see Table 3and Table 4). Vascular risk factors also increase the likelihood of multiple CVD lesions (OR 1.94, 95% CI 1.07-3.52, p=0.03) as does ageing itself (OR 1.15, 95% CI 1.02-1.30, p = 0.03). Multiple CVD lesions (OR 2.36, 95% CI 1.23-4.52, p<0.01), but not single lesions (OR 0.93, 95% CI 0.54-1.60, p=0.80), associate with cognitive impairment or dementia. Logistic regression modelling the effect of age, AD pathology, vascular risk factors and CVD on cognitive impairment for AD spectrum cases with available vascular risk factors (n=421). Similar results were obtained when modelling for dementia (not shown).