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Table 1 Comparisons of SROC curves to predict WS between respiratory muscle assessments

From: Accuracy of respiratory muscle assessments to predict weaning outcomes: a systematic review and comparative meta-analysis

Assessment comparison

Studies

(n)

Patients

(n)

 − 2Log Likelihood values of the fitted models

Likelihood ratio assessments

RDOR (95% CI)

Varied model (V)

Fixed shape model (FS)

Fixed accuracy model (FA)

Model comparison

Chi-square (df = 1)

p value

DE versus PImax

53

3638

857.9

858.2

862.3

FS versus V

0.3

0.58

2.11 (1.14–3.93)

18

1107

FA versus FS

4.1

0.04

DTF versus Pimax

48

3471

798.9

799.3

811.6

FS versus V

0.4

0.53

4.70 (1.71–12.96)

18

1107

FA versus FS

12.3

 < 0.01

DE versus DTF

53

3638

1280.7

1306.7

1306.7

FS versus V

26

 < 0.01

¥

48

3471

FA versus FS

¥

¥

DE versus Tdiee

53

3638

757.4

765.3

769.6

FS versus V

7.9

 < 0.01

¥

11

617

FA versus FS

¥

¥

DTF versus Tdiee

48

3471

774.1

774.1

775.6

FS versus V

0

1

1.46 (0.85–2.50)

11

617

FA versus FS

1.5

0.22

Pimax versus Tdiee

18

1107

336.3

338.8

340

FS versus V

2.5

0.11

1.85 (0.64–5.37)

11

617

FA versus FS

1.2

0.27

Pimax versus P0.1

18

1107

380.6

382.5

383.4

FS versus V

1.9

0.17

0.68 (0.30–1.54)

15

1225

FA versus FS

0.9

0.34

DE versus P0.1

53

3638

782.9

787.1

787.1

FS versus V

4.2

0.04

¥

15

1225

FA versus FS

¥

¥

DTF versus P0.1

48

3471

746.6

748.4

749

FS versus V

1.8

0.18

1.49 (0.50–4.44)

15

1225

FA versus FS

0.6

0.44

P0.1 versus Tdiee

15

1225

312

312.1

312.7

FS versus V

0.1

0.75

1.87 (0.51–6.81)

11

617

FA versus FS

0.6

0.44

  1. To compare SROC curves, the following HSROC models were compared: Model 1 (“Varied”, V) which includes covariates to allow accuracy, threshold and shape to vary by assessment; Model 2 (“Fixed shape”, FS) from which the covariate term for shape was removed, to assume that the SROC curves under comparison have the same shapes; Model 3 (“Fixed accuracy”, FA) from which also the covariate term for accuracy was removed to assume that the SROC curves under comparison have the same accuracy. A significant p value for Model 2 versus 1 denotes that the shapes of the SROC curves under comparison are different; a significant p value for Model 3 versus 2 comparison denotes that the overall accuracies of the assessments under comparison are different. ¥ = in case of a significant p value for Model 2 versus 1, which denotes that the shapes of the SROC curves under comparison are different, further comparisons of Model 3 versus 2 was not performed. Significance level: p < 0.05. Values of RDOR were calculated as relative diagnostic odds ratio of the first assessment compared to the second, as indicated by the order specified in the “Assessment comparison” column. A value of the RDOR higher or lower than 1 indicate that the first assessment has higher or lower accuracy than the second one. Confidence intervals of RDOR not containing 1 indicate significant higher or lower accuracy. Comparisons were not possible for Tdiee and Tdiei due to irregular shape of the SROC curves. Significant p-values (p<0.05) and RDOR 95%CI are highlighted in bold. Abbreviations: CI Confidence interval, DE Diaphragm excursion, DTF Diaphragm thickening fraction, PImax Maximal inspiratory pressure, P0.1 Airway occlusion pressure, Tdiee Diaphragm thickness at end-expiration, df  Degrees of freedom which are equal to the difference in the number of parameters between the models that are compared, RDOR Relative diagnostic odds ratio, WS Weaning success. Bold value indicates statistically significant values
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Critical Care

ISSN: 1364-8535