Should we continue using questionnaires on breathlessness in epidemiologic surveys?

The construct validity and ability to predict mortality on the basis of 4 British Medical Research Council (BMRC) questions on breathlessness were examined and compared to that of spirometric measurements, in particular FEV1, in a cohort of 1,045 men. Of these, 1,030 answered questions on breathlessness and 994 performed acceptable spirometry. Using 2 levels of dyspnea, white collar workers had significantly fewer symptoms of breathlessness than both cement workers and other blue collar workers, and this effect was present even after controlling for FEV1 as well as other spirometric measurements. We found an effect of age on dyspnea but not of smoking category. Furthermore, questions on breathlessness showed a dependence on extreme overweight. In a 10-yr follow-up, 219 men had died. Dyspnea Grade 3 or worse according to Fletcher's breathlessness score was a good predictor of overall mortality, yielding a mortality ratio of 1.57 for given occupation, smoking category, years with central heating, and overweight status, after controlling for FEV1. We conclude that in a standardized setting, questions on breathlessness provide a sensitive and objective tool. They contain information additional to that provided by FEV1 and other spirometric measurements.