# A Retrospective Study Examining the Effectiveness of the Study of the Management of Blunt Chest Wall Trauma (STUMBL) Scoring Tool in Predicting Complications Following Rib Fractures

## TL;DR

This study evaluates how well the STUMBL score predicts complications from rib fractures and finds that a score above 11 is not very effective.

## Contribution

The study identifies a higher STUMBL score threshold (18.5) as more predictive of complications than the previously used score of >11.

## Key findings

- A STUMBL score of >11 had an AUROC of 0.57, indicating poor predictive accuracy for complications.
- An optimal STUMBL score of 18.5 showed better predictive value (AUROC = 0.63) for complications.
- The study found a 37.2% morbidity and 9.3% mortality rate among patients with rib fractures.

## Abstract

Introduction

Blunt thoracic trauma is a significant burden on the United Kingdom’s National Health Service. A common scoring system utilised to predict complications and guide management is the STUMBL (Study of the Management of Blunt Chest Wall Trauma) tool. This study evaluates the utility of a STUMBL score of >11 in predicting complications.

Methods

A retrospective study of patients with rib fractures was conducted at the University Hospitals of North Midlands, a major trauma centre in England. The primary outcome was rib fracture-related complications, defined as the occurrence of ≥1 of the following: 90-day mortality, pulmonary complications (including infection, pleural effusion and empyema, haemothorax, pneumothorax, and pulmonary contusions), ICU admission, or a hospital stay of ≥7 days. The area under the receiver operating characteristic curve (AUROC), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for a STUMBL score >11. Optimal cut-off scores for complications and 90-day mortality were also assessed.

Results

Between 01/06/2021 and 12/09/2023, 438 patients were enrolled in this study. A total of 199 patients were admitted to the hospital. Morbidity and mortality from rib fractures were 37.2% and 9.3%, respectively. The AUROC for a STUMBL score of >11 for all complications was 0.57 (sensitivity = 0.25, specificity = 0.88, PPV = 0.78, NPV = 0.41). The optimal STUMBL score for predicting overall complications and 90-day mortality was 18.5 (AUROC = 0.63) and 17.5 (AUROC = 0.62), respectively.

Conclusion

The STUMBL score of >11 poorly predicts complications in our population, whereas a score of 18.5 is more predictive. Further research is needed to determine if additional factors can enhance the utility of the STUMBL tool.