Fig. 2

ROC curves with 95% CIs for specificity at fixed sensitivities of 0.80, 0.85, 0.90, and 0.95 (indicated by red dots and horizontal error bars) for each HMGB1 diagnostic method. (A) Test-1: Single measurement comparison showing varying specificity ranges at different sensitivity thresholds. (B) Test-2: Baseline difference method demonstrating specificity CIs at fixed sensitivity levels. (C) Test-3: Consecutive measurement comparison displaying specificity ranges at fixed sensitivities. (D) Test-4: Mean comparison method showing notably wide CIs for specificity, particularly at higher sensitivities, despite having the highest overall AUC of 0.888. The diagonal line in each panel represents random chance (AUC = 0.5). AUC: area under the curve; CI: confidence interval; ROC: receiver operating characteristic; HMGB1: high-mobility group box 1.