Table 3

Corrected item-total correlations and internal consistency reliability if item was deleted for baseline scores of the interviewer and self-administered CRQ format

Item

CRQ-IA

CRQ-SA


Corrected item-total correlation

Crohnbach alpha if item deleted

Corrected item-total correlation

Crohnbach alpha if item deleted


Standardised dyspnoea domain

Standardised dyspnoea domain


1

0.46

0.70

0.56

0.74

2

0.68

0.62

0.67

0.71

3

0.50

0.69

0.44

0.78

4

0.32

0.74

0.70

0.71

5

0.56

0.66

0.48

0.77

Fatigue domain

Fatigue domain


8

0.64

0.76

0.56

0.83

11

0.65

0.75

0.67

0.79

15

0.67

0.74

0.67

0.79

17

0.56

0.80

0.78

0.73

Emotional function domain

Emotional function domain


6

0.66

0.71

0.80

0.85

9

-0.03

0.86

0.37

0.92

12

0.72

0.70

0.67

0.87

14

0.41

0.76

0.65

0.88

16

0.84

0.67

0.79

0.86

18

0.56

0.74

0.74

0.87

20

0.57

0.73

0.85

0.85

Mastery domain

Mastery domain


7

0.49

0.75

0.67

0.83

10

0.65

0.66

0.76

0.80

13

0.44

0.78

0.65

0.85

19

0.72

0.63

0.77

0.79


CRQ-IA = Interviewer administered Chronic Respiratory Questionnaire CRQ-SA = Self-administered Chronic Respiratory Questionnaire

Puhan et al. Health and Quality of Life Outcomes 2004 2:1   doi:10.1186/1477-7525-2-1

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