Table 5.

Risk score derived from the model with 4 criteria predicting the presence versus absence of HAEC episodes and estimates of sensitivity and specificity at different threshold values for the risk score.

Risk score*	Number of patients (%)	Crude HAEC episode incidence rate (%)
19	0	Not applicable
15	8 (6.9)	100
14	6 (5.17)	100
10	7 (6.03)	100
9	7 (6.03)	100
5	7 (6.03)	85.71
4	5 (4.31)	60
0	76 (65.52)	7.89

Cut-off value (≥ versus <)	Sensitivity (exact 95% CI) (%)	Specificity (exact 95% CI) (%)	Area under the ROC curve (AUC) (95% CI)
4	86.05 (72.07–94.70)	95.89 (88.46–99.14)	0.910 (0.853–0.967)
5	79.07 (63.96–89.96)	98.63 (92.60–99.97)	0.889 (0.826–0.952)
9	55.12 (49.97–78.99)	100.00(95.07–100)	0.826 (0.754–0.898)
10	48.84 (33.31–64.54)	100.00 (95.07–100)	0.744 (0.669–0.820)
14	32.56 (19.08–48.54)	100.00 (95.07–100)	0.663 (0.592–0.734)
15	18.61 (8.39–33.40)	100.00 (95.07–100)	0.593 (0.534–0.652)

^*Risk score = 5 × diarrhea with explosive stool (1 if presence; 0 if absence) + 5 × -decreased peripheral perfusion (1 if presence; 0 if absence) + 5 × lethargy (1 if presence; 0 if absence) + 4 × dilated loops of bowel on AXR (1 if presence; 0 if absence).