Objective: To evaluate the long-term survival and factors that influence survival among a cohort of elderly trauma patients compared with an uninjured cohort.
Design: A retrospective cohort analysis.
Data sources: Health Care Finance Administration, Baltimore, Md, Medicare data.
Subjects: A cohort of elderly patients (n = 9424) hospitalized for injury in 1987 was identified using Medicare hospital discharge abstract data. An uninjured comparison group (n = 37,787) was identified from Medicare eligibility files. For injured patients, an Injury Severity Score was generated from the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9CM) codes. For both cohorts, preexisting illness was assessed by ICD-9CM codes from Health Care Finance Administration outpatient and inpatient data files for 1986 and 1987.
Main outcome measures: Relative risk for mortality within 5 years subsequent to injury, adjusted for age, sex, and preexisting illness, using Cox proportional hazard regression.
Results: The injured cohort had a significantly reduced 5-year survival when compared with the uninjured group (relative risk [RR] = 1.71; 95% confidence interval, 1.66-1.77). The lower survival persisted even among patients who survived at least 3 years after injury. Coexisting disease, age, and Injury Severity Score were strong predictors of survival.
Conclusions: The adverse effect of trauma on survival in elderly patients is not isolated to the immediate postinjury period, but lasts years after the trauma episode. Further study is required to identify the reasons for this persistent effect of trauma on subsequent survival.