Current occupation was collected as an open-ended variable and coded using the 1980 US Bureau of the Census occupational scaling system, which creates a hierarchy of occupations ordered on the basis of education and income.21 To examine associations between separate occupations and risk factors, we coded each occupation, including homemaker, as an indicator variable, with executives as the reference category. In multivariate mod els, we excluded homemakers and used occupation as a ranked variable ranging from executives to unskilled workers.