Questionnaires

In this issue of the Canadian Respiratory Journal, Bourbeau et al (pages 480-486) publish what could be loosely described as a validation of a French-Canadian translation of the Chronic Respiratory Questionnaire (CRQ) (1) and the St George's Respiratory Questionnaire (SGRQ) (2). They translated the questionnaires and went over them in detail until they were convinced that the questionnaires actually asked the questions that they were supposed to. They then administered them to two groups of chronic obstructive pulmonary disease (COPD) patients. One group had stable COPD and was tested twice with a two-week period between tests to examine test-retest reproducibility. The second group consisted of patients who either had an exacerbation of their COPD or who underwent rehabilitation for their disease. Both situations are associated with improvements in quality of life that should be detectable by the questionnaires. These results were compared with a third standard quality of life questionnaire. The results were very good. The questionnaire results met expectations: they were reproducible in stable patients and showed when patients improved. In psychometric terms, they were reliable and valid. I recommend the paper to people who are interested in developing and testing such instruments, both for the knowledge displayed by the authors and for the clarity of their presentation

Canadian Normal Lung Function Values

In this issue of the Canadian Respiratory Journal, Gutierrez et al (pages 414-424) present normal lung function values and prediction equations for white Canadians. They had six laboratories across the country each test approximately 100 volunteer, nonsmoking white adults (the target was 120 each), with appropriate variation in age and sex. Adequate representation of different ages and sex were obtained, although it appeared to be harder to recruit elderly men than elderly women. A full battery of tests was performed on each person. The equipment was not standardized and varied from centre to centre, and some centres performed slightly different tests than others; in other words, the study was done under field conditions. The results were analyzed for each centre and pooled to produce the Canadian model. This was compared with several similar models developed in Europe and the United States (1-5)