TABLE 5.

Asthma risk stratification based on percentile cut-off.

Percentile	Sensitivity, % (n)	Specificity, % (n)	PPV, % (n)	NPV, % (n)	+LR #	−LR ¶
>50th	78.4 (40/51)	40.9 (9/22)	75.5 (40/53)	45.0 (9/20)	1.3	0.5
>75th	72.5 (37/51)	77.3 (17/22)	88.1 (37/42)	54.8 (17/31)	3.2	0.4
>90th	58.8 (30/51)	95.5 (21/22)	96.8 (30/31)	50.0 (21/42)	13.1	0.4
>98th	33.3 (17/51)	100 (22/22)	100 (17/17)	39.3 (22/56)	∞	0.7

^#: +LR: sensitivity/(1-specificity). ^¶: −LR: (1-sensitivity)/specificity. LR: likelihood ratio; NPV: negative predictive value; PPV: positive predictive value.