Differences in Survival between Patients with Dementia with Lewy Bodies and Patients with Alzheimer's Disease - Measured from a Fixed Cognitive Level

Abstract

Introduction: The aim of this study was to compare survival in patients with Alzheimer's disease (AD) and patients with dementia with Lewy bodies (DLB). Since anamnestic and retrospective information about disease duration are unreliable variables, we measured survival from a fixed cognitive level. Methods: Survival time was measured from the reported disease onset, from the time of diagnosis, from Mini-Mental State Examination (MMSE) 20 ± 1, and from MMSE 17 ± 1. Results: Survival time was significantly shorter in the DLB group compared to the AD group both from the time of diagnosis and from the cognitive levels of 20 and 17 on the MMSE. There was no difference in survival when measured from the reported disease onset. Discussion: Our findings indicate that DLB patients have a more malignant clinical course. Our method of investigating survival in a cognitively homogenous population may gain scientific power. Reliable methods to predict survival and the clinical course are of great value for patients, caregivers, doctors, and society.

Long-Term Mortality in a Cohort of Home-Dwelling Elderly with Mild Alzheimer's Disease and Lewy Body Dementia

“…They support and extend the results of a previous study reporting that the difference in mortality between AD and DLB increases with an MMSE score of approximately 20 [28]. …”

“…Also in line with previous studies, we identified age at baseline and a diagnosis of LBD as predicting factors of mortality [7,28]. The univariable analysis also showed significant results for comorbidity and disease severity.…”

“…This difference in survival rate between LBD and AD is larger than in previous studies. A study from 2000 found no difference in the 3-year survival between AD and DLB [27], while two more recent studies reported significant, but smaller differences [7,28]. One reason for this variation might be that we used the most recent diagnostic criteria for DLB, with a higher sensitivity for identifying patients with DLB compared to the criteria from 1992 and 1996 [29,30].…”

The prognosis of dementia with Lewy bodies

“…Studies have defined survival in two ways, either from onset of disease, or from diagnosis. Survival estimates range between 5.5 and 7.7 years, and between 1.9 and 6.3 years respectively for these two definitions 22,27,32,[44][45][46] . To mitigate potential inaccuracies due to recall bias of duration and delay in diagnosis, Stubendorff and colleagues 45 measured survival from fixed MMSE score points (20±1 and 17±1), demonstrating worse survival in DLB than in AD patients.…”

Lewy body dementia: the impact on patients and caregivers

“…Other comparison studies evaluating survival differences in patients with AD and DLB have found that when comparing the groups based on Mini-Mental State Examination score, the survival time is shorter in DLB [38]. The evidence suggests that DLB patients may have worse mortality outcomes; however, the rate of cognitive decline over time is similar between DLB and AD patients [36].…”