Characteristics and Outcomes of Traumatic Brain Injury among Older Adults with and without Pre‐injury Dementia: an Israel National Trauma Registry Study

Abstract

AbstractBackgroundOlder adults have the highest and fastest rising incidence of traumatic brain injury (TBI) compared to all other age groups. Few studies have examined the prevalence of pre‐injury dementia among older adults presenting with TBI. None have examined injury characteristics and outcomes specifically among those with pre‐injury dementia. Our aim was to describe prevalence of pre‐injury dementia among older adults hospitalized with TBI in Israel and to examine features of those with versus without pre‐injury dementia.MethodWe identified all TBIs recorded in the Israel National Trauma Registry from 2015‐2020 among adults age 65 years and older who were admitted to one of 15 trauma centers. We determined the prevalence of a diagnosis of pre‐injury dementia recorded in the registry and compared baseline demographics, injury features, and hospital outcomes among those with versus without pre‐injury dementia.ResultAmong N = 7,788 identified cases of geriatric TBI, 9.8% (N = 762) had pre‐injury dementia. Compared to those without pre‐injury dementia, those with pre‐injury dementia were significantly older (90% vs. 70% age >75 years), more female (58% vs. 47%), had higher rates of injury location of residential institution (24% vs. 7%) or home (63% vs. 58%), and higher rates of injury mechanism of fall (95% vs. 84%; all p<0.01). No differences were identified in Injury Severity Score (ISS) across groups (p = 0.19). However, those with pre‐injury dementia had lower rates of severe TBI (4% vs. 7% Glasgow Coma Scale <9), lower rates of polytrauma (10% vs. 13%), and lower rates of surgical intervention (9% vs. 13%), yet had higher rates of in‐hospital mortality (10% vs. 8%) and new institutionalization post‐discharge (11% vs. 4%; all p<0.02).ConclusionApproximately 10% of older adults admitted to hospitals in Israel with TBI have dementia compared to only 7% of older adults in the general population (per 2019 national health service data), suggesting that dementia is likely a risk factor for TBI in the elderly. Additionally, admission for a TBI resulted in 10% in‐hospital mortality and 11% new institutionalization post‐discharge among those with pre‐injury dementia. Geriatric TBI prevention, primarily through fall‐prevention, is of high public health importance in Israel.