Comparison of costs of care between patients with Alzheimer's disease and dementia with Lewy bodies

Background: The objective of this study was to compare total costs of care and its major components for community-living patients with Alzheimer's disease (AD) or dementia with Lewy bodies (DLB). This cross-sectional analysis of baseline data from the Predictors II Study took place in three university-based AD centers in the U.S. Methods: Community-living patients clinically diagnosed with probable AD (n = 170) or DLB (n = 25) with a modified Mini-Mental State examination (mMMS) score ≥30, equivalent to a score of approximately ≥16 on the Folstein Mini-Mental State Examination (MMSE), participated in this study. Patient and informant reported on patients' use of direct medical care, direct nonmedical care, and informal care. Patients' clinical and demographic characteristics included global cognitive status (measured by MMSE), functional capacity (measured by Blessed Dementia Rating Scale), psychotic symptoms, behavioral problems, depressive symptoms, extrapyramidal signs, comorbidities, age, and sex. Costs were compared by using covariate matching methods. Results: Unadjusted total costs and direct medical costs were not significantly different between AD and DLB patients. Compared with AD patients, unadjusted indirect costs were significantly higher and unadjusted direct nonmedical costs were significantly lower among DLB patients. After adjusting for age, sex, cognitive and functional status, differences in all cost components between DLB and AD patients were no longer statistically significant. Conclusions: Apparent cost differences were largely attributed to differences in patients' cognitive and functional status. However, the small sample size for DLB patients might have limited power to detect statistically significant differences in costs of care between these groups.