Table 5.

Receiver operating characteristic properties for prediction of re-intubation

	AUROC (95% CI)	Sensitivity (%)	Specificity (%)	PPV (%)	NPV (%)	Cutoff value
Respiratory rate (baseline)	0.73 (0.56–0.87)*	82	60	47	88	> 19
Respiratory rate (30 min)	0.75 (0.58–0.88)*	82	72	56	90	> 22
Respiratory rate ratio	0.64 (0.46–0.79)	91	48	44	92	> 0.95
RSBI (baseline)	0.71 (0.53–0.85)*	82	56	45	88	> 39.5
RSBI (30 min)	0.71 (0.54–0.85)	82	60	47	88	> 42.5
RSBI ratio	0.52 (0.35–0.69)	64	68	47	81	> 1.06
PPI (baseline)	0.54 (0.37–0.71)	36	92	67	74	> 4.4
PPI ratio (15 min)	0.63 (0.45–0.78)	82	44	39	84	≤ 1.34
PPI ratio (30 min)	0.78 (0.61–0.9)*	91	72	59	95	≤ 1.41

^*Denotes statistical significance (P value < 0.05). AUROC Area under receiver operating characteristic curve, CI confidence interval, NPV negative predictive value, PPI peripheral perfusion index, PPV positive predictive value. RSBI rapid shallow breathing index. ^*denotes statistical significance