JAGS 50:1969–1977, 2002 © 2002 by the American Geriatrics Society 0002-8614/02/$15.00 Subcortical Vascular Disease and Functional Decline: A 6-Year Predictor Study Hayley P. Bennett, PhD,* † Alastair J. Corbett, MD, ChB, FRACP, ‡ Susan Gaden, MBBS, FRACR, § David A. Grayson, PhD,  Jillian J. Kril, PhD,* and G. Anthony Broe, MBBS, FRACP* † OBJECTIVES: To identify predictors of activity of daily living (ADL) and instrumental activity of daily living (IADL) decline in a population with subcortical vascular dementia (SVD) and to evaluate potential mechanism of decline. DESIGN: Longitudinal. SETTING: Hospital-based. PARTICIPANTS: Computed tomographic (CT) scanning identified 77 participants as having subcortical infarction. MEASUREMENTS: Participants were neurologically, neuropsychologically, behaviorally, and functionally as- sessed four times over 5.82 years. Baseline data were grouped into four modules: basic demographic and risk factor, CT scan, neurological and other clinical, and neu- ropsychological and behavioral. Multivariate analysis deter- mined predictors of decline in ADLs and IADLs. RESULTS: Predictors of ADL decline were age, alcohol consumption, coordination, snout reflex, and performance on a neuropsychological test (Block Design). Predictors of IADL decline were predominantly cognitive and included the presence of paratonia and performance on the two neuropsychological tests (attention and memory tasks). CONCLUSION: These findings suggest that cognitive impairments are most likely to have an effect on IADL function, because the skills involved are complex and in- volve integrative activity, whereas physical and cognitive impairments combined are likely to compromise ADL function, given the more basic and physical nature of the functions involved. These findings indicate that in people with SVD, both ADL and IADL status should be moni- tored, because, for many, decline in function over time is likely, and thus the provision of appropriate support re- quired. J Am Geriatr Soc 50:1969–1977, 2002. Key words: subcortical infarction; ADL; IADL; decline V ascular dementia (VaD) is a common cause of dementia in the Western world and is the most common cause of dementia in Japan and Russia, 1 with subcortical vascular dis- ease (SVD) cited as being the most prevalent pathological sub- strate of this condition. 2,3 Given the high prevalence of SVD in nondemented older people as well 4 (i.e., lacunae and more diffuse white matter changes 5 ), subcortical vascular damage to the brain is increasingly recognized as a common cause of cognitive impairment not reaching criteria for dementia. 6–9 The cross-sectional associations between (1) SVD and (2) risk factors and radiological, neurological, and neuro- psychological profiles have been described in the litera- ture, 7,10 but little is known about the functional correlates of SVD or of the predictors of decline over time. Func- tional capacity in older people, activities of daily living (ADLs) and instrumental activities of daily living (IADLs), are important to determine, because the consequences of impairment are the need for provision of support, services, and ongoing monitoring in the home; for carer support; and ultimately for institutionalization. 11,12 In the few studies that have examined predictors of functional decline in SVD, decline in ADL function has pre- dominantly been evaluated, and only a restricted range of predictors have been considered. The need to evaluate both ADL and IADL status has been highlighted in the popula- tion-based literature, where IADL functions are reported to require greater cognitive and physical integrative powers. They are considered to be affected by cognitive or physical impairments sooner than ADL skills and thus have a stron- ger association with cognitive than physical impairment, on the assumption that IADL functions involve a more complex level of organized behaviour than basic ADL functions. 13 In one of the few SVD outcome studies, Miyao et al. evaluated ADL decline in lacunar infarction and found that, 1 month after stroke, 30.5% subjects who had leuko- ariosis (LA) in addition to their lacune were partially or From the *Centre for Education and Research on Aging, Concord Hospital and University of Sydney, Australia; † Prince of Wales Medical Research In- stitute, Randwick, Australia; Departments of ‡ Neurology and § Radiology, Concord Hospital, Concord, Australia; and  Department of Psychology, University of Sydney, Sydney, New South Wales, Australia. Funded by COMRAC grant (Australian Commonwealth). Address correspondence to Dr. Hayley Bennett, Prince of Wales Medical Research Institute, Barker Street, Randwick, NSW 2031, Sydney, Australia. E-mail: hayley.bennett@unsw.edu.au