NPHS‐I follows a total of nearly 3,500 white men and women who were working in three industrial or occupational sites in northwest London between 1972 and 1978. Participants were recruited from the headquarters and the main London production site of a food-processing company, from a London borough working as administrative staff or from the Post Office working as part of a telecommunications group. They were assessed at baseline and at follow-up approximately 6 years later, and tracked for non-fatal and fatal events thereafter.