Accounting for intubation status in predicting mortality for victims of motor vehicle crashes

Background: Two of the important predictors of mortality for trauma patient s are the Glasgow Coma Scale and the respiratory rate, However, for intubat ed patients, the verbal response component of the Glasgow Coma Scale and th e respiratory rate cannot be accurately obtained. This study extends previo us work that attempts to predict mortality accurately for intubated patient s without using verbal response and respiratory rate. Methods: The New York State Trauma Registry was used to identify 1994 and 1 995 victims of motor vehicle crashes (MVCs). For the subset of patients who were not intubated, we developed two statistical models to predict mortali ty: one did not contain verbal response or respiratory rate, and the other contained a predicted verbal response. These were compared with a model tha t did include verbal response and respiratory rate. We also compared the pr edictive abilities of the first two models for all MVC patients (intubated and nonintubated) and determined the extent to which intubated patients wer e at increased risk of dying in the hospital after hating adjusted for othe r predictors of mortality. Results: For nonintubated patients, the statistical model without verbal re sponse and the model with predicted verbal response had slightly better dis crimination and worse calibration than the model that included verbal respo nse and respiratory rate. Predicted verbal response did not improve the str ength of the model without verbal response, For all R-NC patients (intubate d and nonintubated), predicted verbal response was not a significant predic tor of mortality when used in combination with the other predictors. Intuba tion status was a significant predictor, with intubated patients having a h igher probability of dying in the hospital than patients with otherwise ide ntical risk factors. Conclusion: Inpatient mortality for intubated MVC patients can be accuratel y predicted without respiratory rate or verbal response. There appears to h e no need for predicted verbal response to be part of the prediction formul a, but intubation status is an important independent predictor of mortality and should be used in statistical models that predict mortality for MVC pa tients.