A comparison of two respiratory symptoms questionnaires.

It is generally recognized that, in epidemiological studies, the diagnosis of chronic bronchitis, and particularly of the early stages of the condition, is an uncertain process which depends essentially upon symptomatic inquiry of the subject.In such studies it is important that the techniques of inquiry should be standardized (Cochrane, Chapman, and Oldham, 1951) so that the results obtained by different investigators in different populations may be com- pared.Considerations of this kind have led to the evolution of questionnaires completed at one inter- view of each subject, which comprise a series of standard questions about particular respiratory symptoms (Fletcher, Elmes, Fairbaim, and Wood, 1959; Fairbairn, Wood, and Fletcher, 1959; Olsen and Gilson, 1960; Higgins, 1961; College of General Practitioners, 1961).In the United Kingdom the Medical Research Council (M.R.C.) Committee on the Aetiology of Chronic Bronchitis produced in 1960 a "Respiratory Symptoms Questionnaire" (Medical Research Council, 1960, 1961) which has since been applied in its original or in a modified form in a wide variety of epidemiological studies in many parts of the world.As part of the National Coal Board's Pneumo- coniosis Field Research (P.F.R.) (Fay, 1957; Fay and Rae, 1959) a short questionnaire about respiratory symptoms has, since 1958, been included in the standard medical examination (Rogan, Ashford, Chapman, Duffield, Fay, and Rae, 1961).To date the PFR Questionnaire has been asked of some 30,000 working coalminers, comprising about 95