Table 4.

Distribution of patients over the AIR-score according to the final diagnosis, and corresponding diagnostic characteristics at all cut-off points

Score points	Numbers according to diagnosis
	NSAP	Appendicitis		Other diagnoses	Total	Cut off points	Sensitivity		Specificity
		Uncomplicated	Complicated				Appendicitis (%)	Complicated (%)	Appendicitis (%)
0	60	0	0	2	62	≥0	100.0	100.0	0.0
1	195	2	1	6	204	≥1	100.0	100.0	2.7
2	323	12	0	21	356	≥2	99.8	99.9	11.3
3	366	39	6	30	441	≥3	99.0	99.9	26.0
4	364	83	25	45	517	≥4	96.1	99.0	43.0
5	292	156	75	62	585	≥5	89.1	95.6	60.5
6	210	183	114	64	571	≥6	74.2	85.2	75.7
7	104	160	137	52	453	≥7	55.0	69.5	87.4
8	50	116	131	41	338	≥8	35.7	50.6	94.1
9	15	55	116	15	201	≥9	19.7	32.5	98.0
10	6	12	76	5	99	≥10	8.7	16.4	99.3
11	1	3	39	1	44	≥11	3.0	5.9	99.8
12	0	0	4	3	7	≥12	0.3	0.6	99.9
Total	1 986	821	724	347	3 878

A new low cut-off point >  = 4 is proposed as the original cut-off point >  = 5 has insufficient sensitivity for complicated appendicitis