The participants' vital status was determined at 2-year intervals through
personal enquiry by the volunteers. Mortality was assessed through August 31.
1988. By then. 79.820 participants (6.7%) had died, 1,083,600 (91.4%) were
alive, and 21.704 (1.8%) were lost to follow-up. Death certificates were ob
tained for 94.1 % of the persons known to have died. A nosologist coded cancer deaths according to the first three digits of the International Classification of
Diseases, 9th revision (ICD-9) (82).