Fig. 4

MDW improves detection of sepsis in ED patients regardless of WBC value at presentation. An elevated MDW value predicts higher sepsis probability in ED patients presenting with abnormal WBC (< 4000 or > 12,000, orange shading) and within the range of normal WBC values (4000–12,000, no shading). In contrast, a normal MDW at presentation to the ED reduces sepsis probability regardless of normal or abnormal WBC value. When all patients with normal CBC are combined, the risk of sepsis is 6-fold higher if MDW is elevated compared to those with a normal MDW value. Notably, 31% of all sepsis cases presented to the ED with a WBC in the normal range. Associated table summarizes sepsis probabilities for combinations of MDW and WBC determined in trial (P₀ = 18%) and modeled at P₀ = 8%. The chart numbers reflect sepsis probabilities at P₀ = 8%. Abnormal WBC cohort combines patients with WBC < 4000 and WBC > 12,000