Risk of Hospitalization in Patients with Alzheimer's Disease and Lewy Body Dementia: Time to and Length of Stay

Background: Patients with dementia are at high risk of being hospitalized, but there is little knowledge whether this applies to all forms of dementia. Objective: To investigate if there are differences in hospitalization between patients with Alzheimer's disease (AD) and Lewy body dementia (LBD), and further, to compare admission rate with the general age-matched population. Methods: Patients (age 75.7 +/- 7.4) recently diagnosed with mild form of AD (n = 110) or LBD (n = 91) were included from outpatient clinics. The participants were followed from time of diagnosis, for five years or until death. Study outcomes were time to first hospitalization after diagnosis, number of admissions, total number of hospital days, and length of stay. Age-standardized admission ratios were calculated. Time to first admission was analyzed using competing risks regression models, and differences in number of hospitalizations and hospital days were addressed using negative binomial regression models. Results: More than 77% of the patients were admitted, largely as unplanned hospitalizations. Patients with LBD had significantly shorter time until first hospitalization (median 1.28 years, 95% CI 0.93-1.67 versus AD: 2.32 years, 95% CI 1.74-3.31) and more days in hospital (median 13 days, IQR 4, 38), than patients with AD (7 days, IQR 0, 18). Conclusion: Our data indicates that patients with LBD have shorter time until first admission and higher admission rate than AD patients. This imposes a great burden on patients, their family, and the health care system. More knowledge about hospital admissions of people with dementia is needed. Future studies should investigate strategies to avoid potentially preventable admissions.