Enarson D A, Schulzer M, Vedal S, Chan-Yeung M
Respiratory Division, Vancouver General Hospital, University of British Columbia, Canada.
Bull Eur Physiopathol Respir. 1987 Jul-Aug;23(4):387-9.
We have performed bronchoprovocation tests with methacholine in 41 patients with asthma due to Western red cedar dust and in 56 office-workers without known respiratory illness. Our purpose was to define a summary statistic for useful bronchial hyperresponsiveness in epidemiologic surveys. We found a significant linear relationship between the concentration of methacholine and the FEV1 response. We noted, in addition, a positive relation between the rate of the FEV1 response per concentration and the level of FEV1. We conclude that a linear dose-response slope, which can be calculated for each individual, provides a comprehensive summary of methacholine bronchoprovocation tests and is useful in epidemiologic surveys.
