Comorbidites resulting in hospitalization are important to document in persons developing dementia in order to better understand the progression and burden of the disease. In this study we investigated rates and predictors of hospitalizations in 3,602 participants of the Cardiovascular Health (CHS) Cognition Study evaluated for dementia during 1992-99. Hospitalizations were verified by medical or HCFA records. Unconditional logistic regression was used to estimate the increased risk of hospitalization by cognitive status and forward stepwise regression identified predictors. Average age of the cohort was 75.1 years. Using data collected prospectively in the CHS including a cerebral MRI, 577 participants were classified with mild cognitive impairment (MCI), and 480 with incident dementia including 245 with AD, 62 with VaD, and 151 with mixed dementia (both AD and VaD). During 5.4 years of follow-up, more persons with cognitive problems were hospitalized: 64% with normal cognition, 75% with MCI, 77% with AD, 84% with mixed dementia and 98% of those with VaD (p < .001). Adjusted for age, gender and race, persons with dementia were more than twice as likely to be hospitalized (OR: 2.3, 95% CI: 1.7-2.9) compared to those with normal cognition. Those with MCI were at a 70% increased risk of hospitalization (OR: 1.7, 95% CI: 1.4-2.2). Persons hospitalized at least once were hospitalized an average of 3.8 times during follow-up if classified with dementia (3.2 with AD, 4.6 with VaD) compared to 3.2 times for those with MCI and 2.7 times for those with normal cognition. The rate of total hospitalization for those with normal cognition was 297 per 1000 person- years, 432 for persons with MCI and 1049 for incident dementia including 842 for AD, 1690 for VaD, and 1120 for mixed dementia. Adjusted for age and cognition, predictors of hospitalization included race, gender, site, presence of cardiovascular disease, low ankle-arm index, difficulty with ADLs, greater carotid intima-media thickness, walking speed, self-perceived health, and weight. Because the num-ber and length of hospitalizations increase as cognition declines, care-ful observation and additional preventive care may help reduce this burden.

Objective

The authors evaluated 3,375 participants without dementia at the time of MRI in 1991 to 1994 over 5.7 years for incident dementia and type of dementia.

Methods

Incidence of and risk factors for vascular dementia (VaD) were measured using both pre-MRI and modified State of California Alzheimer's Disease Diagnostic and Treatment Centers (ADDTC) post-MRI review and further classified Alzheimer disease (AD) by the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) criteria.

Results

Approximately 44% (213) of 480 incident dementia cases were classified as possible or probable VaD by ADDTC. The incidence of VaD increased with age and was greater in blacks than whites. Risk factors for VaD included age, Modified Mini-Mental State Examination, high white matter grade, number of MRI infarcts, ventricular size, and history of stroke.

Conclusions

Vascular disease in the brain is prevalent among incident dementia cases. There is a substantial overlap between cases classified as Alzheimer disease by Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association and vascular dementia (VaD) by modified State of California Alzheimer's Disease Diagnostic and Treatment Centers criteria. The substantial contribution of vascular disease would be missed without inclusion of MRI. Treatment of risk factors for VaD could have an important impact on incidence of dementia.

Objective

To describe the diagnostic classification of subjects with incident vascular dementia (VaD) participating in the Cardiovascular Health Study (CHS) Cognition Study.

Methods

The CHS classified 480 incident cases between 1994 and 1999 among 3,608 CHS participants who had brain MRI in 1992 through 1994 and in 1997 through 1998. The patients were diagnosed before and after reviewing the brain MRI.

Results

The pre-MRI classification showed that 52 participants had VaD and 76 had both Alzheimer disease (AD) and VaD. The post-MRI classification showed that the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) criteria classified 61 subjects as having VaD, the National Institute of Neurological Disorders and Stroke-Association Internationale pour la Recherche et l'Enseignement en Neurosciences (NINDS-AIREN) criteria classified 43 subjects as having probable VaD and 10 as possible VaD, and the State of California Alzheimer's Disease Diagnostic and Treatment Center (ADDTC) criteria classified 117 as having probable VaD and 96 as possible. The combination of the ADDTC and National Institute of Neurological and Communication Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria was used to examine the spectrum of vascular disease in dementia. The dementia was attributable to only vascular factors in 56 cases (probable VaD); VaD coexisted with AD in 61 cases, although the VaD component was the leading cause of dementia (probable VaD with AD); AD was the leading cause of dementia in 61 cases (possible VaD and probable AD); and in 29 cases, it was not clear that either AD or VaD was the primary diagnosis (possible AD and possible VaD).

Conclusions

None of the clinical criteria for VaD identified the same group of subjects. The diagnosis of vascular dementia is difficult in epidemiologic studies because poststroke dementia can be due to Alzheimer disease (AD) and evidence of vascular disease can be found in the MRI of dementia cases without clinical strokes. Whether the clinical progression is related to AD pathology or vascular disease is difficult to establish.