Development of a self-reported Chronic Respiratory Questionnaire (CRQ-SR)

Background-The Chronic Respiratory Questionnaire (CRQ) is an established me asure of health status for chronic obstructive pulmonary disease (COPD). It has been found to be reproducible and sensitive to change, but as an inter viewer led questionnaire is very time consuming to administer. A study was undertaken to develop a self-reported version of the CRQ (CRQ-SR) and to co mpare the results of this questionnaire with the conventional interviewer l ed CRQ (CRQ-IL). Methods-Fifty two patients with moderate to severe COPD participated in the study. Subjects completed the CRQ-SR 1 week after completing the CRQ-IL, a nd a further CRQ-SR was administered 1 week later. For patients in group A (n=27) the dyspnoea provoking activities that they had previously selected were transcribed onto the second CRQ-SR, while patients in group B (n=25) w ere not informed of their previous dyspnoea provoking activities when they completed the second CRQ-SR. To assess the short term reproducibility and r eliability of the CRQ-SR it was then administered twice at an interval of 7 -10 days to a further group of 21 patients. The CRQ-IL was not administered . Longer term reproducibility was examined in 39 stable patients who comple ted the CRQ-SR at initial assessment and then again 7 weeks later. Results-Mean scores per dimension, mean differences, and limits of agreemen t are given for each dimension in the comparison of the two questionnaires. There were no statistically significant differences between the CRQ-IL and CRQ-SR in the mastery and fatigue dimensions (p >0.05). A statistically si gnificant difference between the two scores was found in the dyspnoea dimen sion (p=0.006) and the emotional function dimension (p=0.04), but these dif ferences were well within the minimum clinically important threshold. No st atistically significant difference in the mean dyspnoea score was seen betw een groups A and B. The CRQ-SR was found to be reproducible both in the sho rt term and after the longer period of 7 weeks, with no statistically or cl inically significant differences in any dimension. Test-retest reliability was found to be high in each dimension, both in the short and longer term. Conclusions-The CRQ-SR is a reproducible, reliable, and stable measure of h ealth status. It compares well with the CRQ-IL but cannot be used interchan geably. The main advantage of the CRQ-SR over the CRQ-IL is that is quick t o administer, reducing assessment time and hence cost.