Determination of surgical priorities in appendicitis based on the probability of undetected appendiceal perforation

Table 3 Risk estimation of developing actual appendiceal perforation

Groups	No. of risk factors1	Ratio of patients with perforation vs total population	Hazard ratio of perforation	95%CI	P value
Control group	0-1		1
Intermediate risk group	2	52/581 (9.0%)	4.8	2.416-9.563	< 0.001
High risk group	3-4	28/156 (17.9%)	10.7	5.064-22.596	< 0.001

¹The risk factors are (1) patient age ≥ 65 years; (2) body temperature ≥ 37.8 years; (3) body temperature n≥ 8 mm; and (4) out-of-hospital symptom duration ≥ 72 h.