VARIATION IN BRONCHIAL RESPONSIVENESS IN THE EUROPEAN-COMMUNITY RESPIRATORY HEALTH SURVEY (ECRHS)

Attempts to compare bronchial responsiveness between populations have been hampered by between-study differences in the pharmacological agen t of provocation, the method of administration and the summary statist ic employed, The European Community Respiratory Health Survey used met hacholine challenge delivered by Mefar dosimeter according to a standa rdized protocol used in 35 centres in 16 countries, Data were obtained from 13,161 men and women, aged 20-44 yrs at the start of the study, The dose of methacholine producing a 20% fall in forced expiratory vol ume in one second (FEV1) (PD20) and the regression coefficient of perc entage decline in FEV1 with log dose, were calculated (''slope'', afte r transformation), with and without calibration of nebulizers by weigh t and adjustment for nonresponse bias, Standardization for baseline lu ng function and variation in smoking prevalence was applied to slope, Results were robust to whichever summary measure was used, and to the various adjustments, Responsiveness was low in Iceland and Switzerland , and in most centres in Sweden, Italy and Spain, and high in New Zeal and, Australia, the USA, Britain, France, Denmark and Germany, Bronchi al responsiveness varies considerably in Europe, and high levels are n ot confined to the English-speaking world.