Table 1 Demographic characteristics of the shipyard cohort
Demographic characteristicsSubjects, n (%)Person-years, n (%)
Ethnicity and sex
    Men4413 (93.9)140328 (93.1)
    White3472 (73.8)109507 (78.0)
    Black941 (20.0)30821 (22.0)
    Women289 (6.1)9721 (6.9)
    White252 (5.4)9080 (6.0)
    Black37 (0.8)1285 (0.9)
Year entry into study
    1950–43276 (69.7)108436 (72.0)
    1955–9662 (14.1)20367 (13.5)
    1960–4764 (16.2)21890 (14.5)
Age at entry (years)
    ⩽25822 (17.5)31856 (21.1)
    26–402378 (50.6)82581 (54.8)
    41–551283 (27.3)32778 (21.8)
    ⩾56219 (4.7)3477 (2.3)
Age at exit
    ⩽40154 (3.3)959 (0.6)
    41–55605 (12.9)10446 (6.9)
    56–701713 (36.4)48993 (32.5)
    ⩾712230 (47.4)90295 (59.9)
Duration of follow-up
    ⩽301959 (41.7)35675 (23.7)
    31–35539 (11.5)17572 (11.7)
    36–40644 (13.7)24255 (16.1)
    ⩾411560 (33.2)73190 (48.6)
Vital status
    Alive1058 (22.5)49388 (32.8)
    Deceased3331 (70.8)97700 (64.8)
    Unknown313 (6.7)3604 (2.4)
    Total4702 (100)150693 (100)