Impact of Dementia on Days at Home after Traumatic Brain Injury among Older Medicare Beneficiaries

Abstract

AbstractBackgroundTraumatic brain injury (TBI) is a highly disabling event among older adults, contributing to disability in activities of daily living and elevated risk for nursing home admission. Older adults with Alzheimer’s disease and related dementias (ADRD) are more susceptible to TBI given increased fall incidence in this population, but how ADRD influences long‐term disability outcomes after TBI has been challenging to ascertain because of small sample sizes in prior work. Home time, a claims‐based measure of time spent at home and not hospitalized following a health‐related event, may aid in determining the association of ADRD and post‐TBI outcomes among older adults. Thus, the objective of this study was to examine the impact of TBI on home time among older adults with ADRD.MethodsWe conducted a retrospective cohort study using a random sample of Medicare administrative claims data for years 2010‐2018. Community‐dwelling Medicare beneficiaries aged ≥65 years hospitalized with a primary diagnosis of TBI were included and ADRD was defined at baseline (i.e. before TBI) using diagnostic codes. Home time was calculated by subtracting the number of days spent in a care environment or deceased from the total follow‐up available for each of the twelve follow‐up months post‐TBI. We modelled monthly days at home as a function of ADRD and covariates using generalized estimating equations.ResultsThere were 20,350 participants in the study, of whom 6,683 (33.8%) had a pre‐existing diagnosis of ADRD. In regression models that accounted for pre‐TBI days at home, demographic and clinical characteristics, and probability of survival, beneficiaries with ADRD spent fewer days at home following TBI compared to beneficiaries without ADRD (rate ratio 0.90; 95% confidence interval 0.89, 0.92). This disparity was equivalent to almost 50 fewer days spent at home over the year following TBI.ConclusionTBI resulted in a significant loss of home time over the year following injury, a loss markedly worse among older adults with ADRD.