Validation of a Geriatric Trauma Prognosis Calculator: A P.A.L.Li.A.T.E. Consortium Study

Abstract

Background/objectives: The P.A.L.Li.A.T.E. (prognostic assessment of life and limitations after trauma in the elderly) consortium has previously created a prognosis calculator for mortality after geriatric injury based on age, injury severity, and transfusion requirement called the geriatric trauma outcome score (GTOS). Here, we sought to create and validate a prognosis calculator called the geriatric trauma outcome score ii (GTOS II) estimating probability of unfavorable discharge.

Design: Retrospective cohort.

Setting: Four geographically diverse Level 1 trauma centers.

Participants: Trauma admissions aged 65 to 102 years surviving to discharge from 2000 to 2013.

Intervention: None.

Measurements: Age, injury severity score (ISS), transfusion at 24 hours post-admission, discharge dichotomized as favorable (home/rehabilitation) or unfavorable (skilled nursing/long term acute care/hospice). Training and testing samples were created using the holdout method. A multiple logistic mixed model (GTOS II) was created to estimate the odds of unfavorable disposition then re-specified using the GTOS II as the sole predictor in a logistic mixed model using the testing sample.

Results: The final dataset was 16,114 subjects (unfavorable discharge status = 15.4%). Training (n = 8,057) and testing (n = 8,057) samples had similar demographics. The formula based on the training sample was (GTOS II = Age + [0.71 × ISS] + 8.79 [if transfused by 24 hours]). Misclassification rate and AUC were 15.63% and 0.67 for the training sample, respectively, and 15.85% and 0.67 for the testing sample.

Conclusion: GTOS II estimates the probability of unfavorable discharge in injured elders with moderate accuracy. With the GTOS mortality calculator, it can help in goal setting conversations after geriatric injury.

Keywords: elderly; geriatric; outcomes; prognosis calculator; scoring system; trauma.