Mortality rates and proximal causes of death in patients with Lewy body dementia versus Alzheimer's disease: A longitudinal study using secondary care mental health records

Abstract

Background Previous studies have shown reduced survival in Lewy body dementia (LBD) compared to Alzheimer’s disease (AD), but the reasons for this are not known. We identified cause of death categories accounting for the reduced survival in LBD. Methods We linked cohorts of patients with dementia with Lewy bodies (DLB), Parkinson’s disease dementia (PDD) and AD, with proximal cause of death data. We examined mortality by dementia group and hazard ratios for each death category by dementia group in males and females separately. In a specific focus on the dementia group with the highest mortality rate versus reference, we examined cumulative incidence to identify the main causes of death accounting for the excess deaths. Results Hazard ratios for death were higher in PDD and DLB compared to AD, for both males and females. PDD males had the highest hazard ratio for death across the dementia comparison groups (HR 2.7, 95% CI 2.2–3.3). Compared with AD, hazard ratios for “nervous system” causes of death were significantly elevated in all LBD groups. Additional significant cause‐of‐death categories included aspiration pneumonia, genitourinary causes, other respiratory causes, circulatory and a “symptoms and signs” category in PDD males; other respiratory causes in DLB males; mental disorders in PDD females; and aspiration pneumonia, genitourinary and other respiratory causes in DLB females. Conclusion Further research and cohort development is required to investigate differences by age group, to extend cohort follow‐up to the whole population and to investigate the risk‐balance of interventions which may differ by dementia group.

Trends in cause-specific mortality among persons with Alzheimer’s disease in South Carolina: 2014 to 2019

“…Overall, in the case of this study, AD was not underreported in the state of South Carolina as reported in other studies ( Kershenbaum et al, 2023 ). In fact, Alzheimer’s disease was listed as the first immediate cause of death among most racial/ethnic groups who had a diagnosis of dementia.…”

“…Death certificate information related to AD can be misinterpreted because of other common causes of death, including cardiovascular disease ( Park, 2016 ; Stern et al, 2020 ). Respiratory and nervous system complications ( Kershenbaum et al, 2023 ) are also contributing factors that often supersede AD on death certificates. At the time of the James et al report (2014) AD was estimated as the third immediate cause of death, with dementia having a survival rate like cardiovascular disease.…”