Table 3

Stratified lung cancer mortality results for Painesville, Ohio chromate production workers, follow up 1940 to 1997, Ohio white male reference rates (n=482, 14048 person-years)

Stratification variableEmployees*Person-yearsObsExpSMR95% CITrend†
*The number of employees in the analyses for Duration of employment and Time since first exposure represent the number contributing person-years to each stratum. The time dependent method of person-years accumulation means that all employees contribute person-years to the lowest stratum, while fewer contribute to each successive higher stratum.
†p values from two sided Poisson trend test for an effect of exposure.
‡Person-years for the cumulative exposure strata total 14100, due to use of a different application for this analysis.
Year of hire0.005
    1940–19491966598309.2326220 to 465
    1950–19591403897155.5275154 to 454
    1960–1971146355366.59234 to 201
Duration of employment (y)*0.0001
    1–4482531196.613762 to 260
    5–9314357685.016069 to 314
    10–19201297074.116968 to 349
    20–321062191275.4497328 to 723
Time since first exposure (y)*0.12
    0–9482406421.513116 to 473
    10–19430401553.713644 to 317
    20–293663104165.8277158 to 449
    30 or more25728652810.2275183 to 398
Cumulative hexavalent exposure, mg/m3-y‡0.00002
    0.00–0.19295234.56714 to 196
    0.20–0.48236984.418479 to 362
    0.49–1.04307744.49125 to 234
    1.05–2.693220164.4365208 to 592
    2.70–232482204.3463283 to 716