Table 2 Variables and diagnostic accuracy for HFNC outcomes (n = 81)

ROX

 Before initiation of HFNC

67

15.15

(11.90–17.71)

14

14.09

(11.15–16.75)

0.359

0.578 (0.422–0.734)

 2 h

67

14.41

(10.67–20.00)

14

7.87

(6.52–11.40)

 < 0.001**

0.822

(0.695–0.949)

 6 h

60

13.05

(10.92–18.47)

11

8.75

(5.64–18.94)

0.015*

0.731

(0.525–0.937)

 12 h

53

13.06

(10.45–17.01)

10

8.34

(6.35–15.67)

0.077

0.677

(0.450–0.904)

ROX-HR

 Before initiation of HFNC

67

17.22

(12.63–21.01)

14

15.63

(12.52–19.63)

0.284

0.591

(0.445–0.737)

 2 h

67

16.04

(11.67–22.30)

14

8.44

(6.28–11.87)

 < 0.001**

0.834

(0.719–0.949)

 6 h

60

14.62

(11.08–20.56)

11

8.75

(5.64–18.94)

0.006**

0.763

(0.585–0.941)

 12 h

53

14.94

(10.98–20.07)

10

9.87

(5.58–19.43)

0.094

0.668

(0.447–0.889)

ROX-HR-flow

 Before initiation of HFNC

67

17.80

(14.17–23.17)

14

17.27

(12.52–20.72)

0.355

0.579

(0.430–0.728)

 2 h

67

18.38

(12.72–24.32)

14

8.77

(6.28–11.95)

 < 0.001**

0.854

(0.756–0.952)

 6 h

60

18.25

(11.66–27.01)

11

8.75

(5.64–18.94)

0.002**

0.794

(0.636–0.952)

 12 h

53

17.40

(14.42–23.94)

10

9.87

(5.58–19.43)

0.020*

0.734

(0.539–0.929)