Association Between Injury Etiology and Scar Outcomes: A Retrospective Clinical Study

ABSTRACT Background While scar formation significantly impacts the quality of life post‐injury, the prognostic value of the initial injury etiology remains uncertain. This study aimed to elucidate the relationship between injury etiology and scar prognosis, and to develop a clinically applicable predictive tool and clinical treatment strategies. Methods In this single‐center retrospective cohort study, clinical data pertaining to 1 160 scar patients who completed a 1.5‐year follow‐up were analyzed at Changhai Hospital from 2013 to 2023. Demographic, injury etiology, treatment, and outcome data were collected for subsequent analysis. A prognostic nomogram was developed based on significant predictors identified through univariate and multivariate logistic regression. Its performance was validated using receiver operating characteristic (ROC) curves, calibration plots, and decision curve analysis (DCA). Model interpretability was enhanced using SHapley Additive exPlanations (SHAP). Subgroup analyses explored mediating factors. Results Injury etiology was a significant predictor of scar prognosis ( p < 0.001). Burn injury was associated with the highest risk of non‐improvement (OR = 2.36, 95% CI: 1.62–3.44). The nomogram, incorporating gender, age, injury etiology, and scar stage at initial treatment, showed modest discriminatory performance (AUC: 0.606 in training, 0.633 in test sets). SHAP analysis confirmed injury etiology as the influential predictive feature. Subgroup analyses revealed that burn wounds were characterized by a larger area, greater depth, prolonged healing time, and subsequently, a longer scar formation latency. Conclusion The study found that injury etiology was significantly correlated with scar prognosis, and burn‐induced scars presented with significantly poorer prognosis than other etiologies. This might be attributed to the depth of tissue damage, a sustained pro‐fibrotic inflammatory response, and prolonged wound healing time commonly observed in burn injuries. It can be inferred that early identification of high‐risk patients based on injury etiology is crucial for initiating timely and intensive scar management to improve outcomes.