Long-term survival of adult trauma patients

Abstract

Context: Inpatient trauma case fatality rates may provide an incomplete assessment for overall trauma care effectiveness. To date, there have been few large studies evaluating long-term mortality in trauma patients and identifying predictors that increase risk for death following hospital discharge.

Objectives: To determine the long-term mortality of patients following trauma admission and to evaluate survivorship in relationship with discharge disposition.

Design, setting, and patients: Retrospective cohort study of 124,421 injured adult patients during January 1995 to December 2008 using the Washington State Trauma Registry linked to death certificate data.

Main outcome measures: Kaplan-Meier and Cox proportional hazards models were used to evaluate long-term mortality following hospital admission for trauma.

Results: Of the 124,421 trauma patients, 7243 died before hospital discharge and 21,045 died following hospital discharge. Cumulative mortality at 3 years postinjury was 16% (95% confidence interval [CI], 15.8%-16.2%) compared with the expected population cumulative mortality of 5.9% (95% CI, 5.9%-5.9%). In-hospital mortality improved during the 14-year study period from 8% (n = 362) to 4.9% (n = 600), whereas long-term cumulative mortality increased from 4.7% (95% CI, 4.1%-5.4%) to 7.4% (95% CI, 6.8%-8.1%). After adjustments for confounders, patients who were older and those who were discharged to a skilled nursing facility had the highest risk of death. The adjusted hazard ratios (HRs) for death after discharge to a skilled nursing facility compared with that after discharge home were 1.41 (95% CI, 0.72-2.76) for patients aged 18 to 30 years, 1.92 (95% CI, 1.36-2.73) for patients aged 31 to 45 years, 2.02 (95% CI, 1.39-2.93) for patients aged 46 to 55 years, 1.93 (95% CI, 1.40-2.64) for patients aged 56 to 65 years, 1.49 (95% CI, 1.14-1.94) for patients aged 66 to 75 years, 1.54 (95% CI, 1.27-1.87) for patients aged 76 to 80 years, and 1.38 (95% CI, 1.09-1.74) for patients older than 80 years. Other significant predictors of mortality after discharge included maximum head injury score on Abbreviated Injury Score scale (HR, 1.20; 95% CI, 1.13-1.26), Injury Severity Score (HR, 0.98; 95% CI, 0.97-0.98), Functional Independence Measure (HR, 0.89; 95% CI, 0.88-0.91), mechanism of injury being a fall (HR, 1.43; 95% CI, 1.30-1.58), and having Medicare (HR, 1.28; 95% CI, 1.15-1.43) or other government insurance (HR, 1.65; 95% CI, 1.47-1.85).

Conclusions: Among adults admitted for trauma in Washington State, 3-year cumulative mortality was 16% despite a decline in in-hospital deaths. Discharge to a skilled nursing facility at any age following trauma admission was associated with a higher risk of subsequent mortality.