RDW-SD and PCT Are Potential Prognostic Factors for In-hospital Death in Patients With Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis

PURPOSE: Our study aimed to explore potential prognostic factors in Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) patients from easily accessible laboratory data and to investigate whether the combination of these indicators with a score for toxic epidermal necrolysis (SCORTEN) can improve the predictive value. METHODS: Data from 85 SJS/TEN patients hospitalized from 2010 to 2021 were retrospectively analyzed. The primary outcome was in-hospital mortality. Univariate analysis was used to screen for laboratory indexes associated with death. Logistic regression was used to analyze significant risk factors for death. The differentiation and calibration of SCORTEN and modified score were assessed using receiver operating characteristic (ROC) curves and Hosmer-Lemeshow goodness-of-fit test. Net reclassification improvement (NRI) and integrated discrimination improvement (IDI) were used to evaluate the incremental prognostic value. RESULTS: Among the 85 patients (37 males, 48 females) aged 14-88 years, the mortality rate was 11.8% (n = 10). SCORTEN had good discrimination and calibration to predict mortality in this cohort of patients (area under the ROC curve [AUC] of 0.874, 95% confidence interval [CI], 0.758-0.990; Hosmer-Lemeshow goodness-of-fit test P = 0.994). Red cell distribution width-standard deviation index (RDW-SD) > 47.9 fL and procalcitonin (PCT) > 0.67 ng/mL were significant risk factors for death. When adding the 2 factors to SCORTEN, AUC was 0.915 (95% CI, 0.833–0.997), but not statistically different compared to SCORTEN alone (P = 0.091). The NRI was 1.2 (95% CI, 0.672–1.728; P < 0.001) and the IDI was 0.09 (95% CI, 0.011–0.173; P = 0.026), still suggesting that the modified score had better discriminatory and predictive power than SCORTEN alone. The modified score also showed good calibration (Hosmer-Lemeshow goodness-of-fit test, P = 0.915). CONCLUSIONS: SCORTEN is a good predictor of mortality in SJS/TEN patients in southwest China. Combining RDW-SD > 47.9 fL and PCT > 0.67 ng/mL with SCORTEN may enhance the ability to predict prognosis.