Does chest wall Organ Injury Scale (OIS) or Abbreviated Injury Scale (AIS) predict outcomes? An analysis of 16,000 consecutive rib fractures.

BACKGROUND

Chest wall injuries have serious clinical consequences. It is presumed a higher severity of injury correlates with worse outcomes. The 2 most common chest wall injury severity scores, the Organ Injury Scale and the Abbreviated Injury Scale, are based on expert opinion with unknown clinical endpoints. Our aim was to determine if either the Organ Injury Scale or the Abbreviated Injury Scale are associated with clinical outcomes.

METHODS

A single institution, 4-year retrospective study of all patients with rib or sternal fractures was conducted. All patients were assessed for both Organ Injury Scale and Abbreviated Injury Scale scores. Outcomes assessed included mortality, complications, tracheostomy, and readmissions. Receiver operating characteristic areas under the curve were calculated to measure discriminatory accuracy of scoring systems for outcomes in chest wall injury.

RESULTS

Overall, 3,033 patients presented with a total of 16,055 rib fractures. The median chest wall scores were 2 for Organ Injury Scale and 3 for Abbreviated Injury Scale. Abbreviated Injury Scale scores for the same patients were greater than the Organ Injury Scale in 48.7%, equivalent in 46.7%, and lower in 4.6%. The receiver operating characteristic areas under the curve for in-hospital outcomes were weakly predictive for the Organ Injury Scale over the Abbreviated Injury Scale. The receiver operating characteristic areas under the curve for readmissions were very weakly predictive for the Abbreviated Injury Scale over the Organ Injury Scale.

CONCLUSION

There is a very weak association between chest wall Organ Injury Scale score and in-hospital outcomes. The Abbreviated Injury Scale score outperformed the Organ Injury Scale, only being weakly predictive of readmission. Chest wall injury scoring systems may need revision for future outcomes-based research and practice improvements.