The disease status of the workers was determined by res-
olution of the links in the incidence file. Workers with mul-
tiple incidence links had their links resolved by manual
inspection on a case-by-case basis (835 persons, 321 males
and 514 females). In the case of multiple incidences, only
the first incidence was included in the analysis. The links of
workers with one incidence link were resolved by proba-
bilistic record linkage (7,036 persons, 3,154 males and
3,882 females).