Outcomes of Older Adults Admitted to a Level I Trauma Center

Abstract

Background: The outcomes of injury and the associated risk factors among older adults are poorly understood. Objective: To examine the associations of pre-existing medical conditions (PMCs) and mechanism of injury (MOI) with the outcomes and to estimate the impact of injury upon long-term mortality of older adults. Methods: Injured older adults admitted to the Shock Trauma Center, University of Maryland Medical Center, between July 1, 1995 and November 30, 2008 were followed until the end of 2008. Logistic regression and Cox proportional hazard models were fit to analyze the outcomes. Standardized mortality ratios (SMRs) and relative survival ratios (RSRs), comparing the observed to the expected proportion of Maryland older adult population were calculated. Results: Among 6,162 injured older adults, 27% developed in-hospital complications, 15% (N=918) died within 30 days of admission, and 43% (N=2,323) of those who were discharged died during the follow-up. Hypertension, prior myocardial infarction, congestive heart failure, and chronic obstructive pulmonary disease (COPD) were associated with increased odds of in-hospital complications, with adjusted ORs ranging from 1.2 (95% confidence interval (CI): 1.1-1.5) to 2.2 (95% CI: 1.6-3.0). Hypertension was associated with lower odds (OR=0.7, 95% CI: 0.6-0.8) while COPD with increased odds of 30-day mortality (OR=1.5, 95% CI: 1.1-2.1). All PMCs, except hypertension, were associated with increased hazard of death after discharge (adjusted hazard ratios range: 1.1-1.7). MVC injuries were associated with higher odds of complications than fall injuries (adjusted ORs range: 1.3-2.2). Older adults with MVC injuries had lower odds of 30-day mortality (OR=0.8, 95% CI: 0.6-0.9) and a lower hazard of death after discharge (HR=0.6, 95% CI: 0.6-0.7). SMR was 4.5 (95% CI: 4.1-4.8) at 6 months and 1.4 (95% CI: 1.2-1.5) between 5-10 years after discharge. The RSR was 91.0% (95% CI: 90.1%-91.9%) at 6 months and 72.6% (95% CI: 69.3%-75.8%) at 10 years after discharge. Conclusions: The associations between PMCs and outcomes are disease-specific. Older adults sustaining MVC injuries have a better survival compared to those sustaining fall injuries. The impact of injury on mortality is most evident during the first 6 months after discharge and can last as long as 10 years.