Table 2.

Diagnostic performance of flow index to detect low inspiratory effort using the cutoff value derived from the present study^a

Definition	Sensitivity	Specificity	PPV	NPV	Accuracy
WOB	0.95 (0.87–0.99)	0.71 (0.54–0.85)	0.84 (0.76–0.90)	0.90 (0.75–0.97)	0.86 (0.78–0.92)
PTPes per minute	0.96 (0.87–0.99)	0.57 (0.42–0.71)	0.70 (0.63–0.76)	0.93 (0.78–0.98)	0.77 (0.68–0.85)
Pmus	0.96 (0.87–0.99)	0.62 (0.47–0.76)	0.76 (0.68–0.82)	0.93 (0.78–0.98)	0.81 (0.72–0.88)

^aThe cutoff value of flow index derived from the present study was 2.1

Between parentheses is the 95% confidence interval (95% CI)

Abbreviations: NPV negative predictive values, P_mus inspiratory muscle pressure, PPV positive predictive values, PTP_es esophageal pressure–time product, WOB work of breathing