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