One-year mortality in geriatric trauma patients: Improving upon the geriatric trauma outcomes score utilizing the social security death index

Abstract

Background: Geriatric Trauma Outcomes Score (GTOS) predicts in-patient mortality in geriatric trauma patients and has been validated in a prospective multicenter trial and expanded to predict adverse discharge (GTOS II). We hypothesized that these formulations actually underestimate the downstream sequelae of injury and sought to predict longer-term mortality in geriatric trauma patients.

Methods: The Parkland Memorial Hospital Trauma registry was queried for patients 65 years or older from 2001 to 2013. Patients were then matched to the Social Security Death Index. The primary outcome was 1-year mortality. The original GTOS formula (variables of age, Injury Severity Score [ISS], 24-hour transfusion) was tested to predict 1-year mortality using receiver operator curves. Significant variables on univariate analysis were used to build an optimal multivariate model to predict 1-year mortality (GTOS III).

Results: There were 3,262 patients who met inclusion. Inpatient mortality was 10.0% (324) and increased each year: 15.8%, 1 year; 17.8%, 2 years; and 22.6%, 5 years. The original GTOS equation had an area under the curve of 0.742 for 1-year mortality. Univariate analysis showed that patients with 1-year mortality had on average increased age (75.7 years vs. 79.5 years), ISS (11.1 vs. 19.1), lower GCS score (14.3 vs. 10.5), more likely to require transfusion within 24 hours (11.5% vs. 31.3%), and adverse discharge (19.5% vs. 78.2%; p < 0.0001 for all). Multivariate logistic regression was used to create the optimal equation to predict 1-year mortality: (GTOSIII = age + [0.806 × ISS] + 5.55 [if transfusion in first 24 hours] + 21.69 [if low GCS] + 34.36 [if adverse discharge]); area under the curve of 0.878.

Conclusion: Traumatic injury in geriatric patients is associated with high mortality rates at 1 year to 5 years. GTOS III has robust test characteristics to predict death at 1 year and can be used to guide patient centered goals discussions with objective data.

Level of evidence: Prognostic, level III.