Proportions and means+ for established risk factors in the Whitehall, Collaborative and Renfrew & Paisley studies by social class.

+Prevalences and means are adjusted for age (age is unadjusted).*FEV ratio is the ratio of measured FEV divided by predicted FEV calculated from subjects’ age and height based on an equation derived in those men free of respiratory symptoms in the Renfrew & Paisley study.