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 variable | Employees* | Person-years | Obs | Exp | SMR | 95% CI | Trend† |
|---|---|---|---|---|---|---|---|
| *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 hire | 0.005 | ||||||
| 1940–1949 | 196 | 6598 | 30 | 9.2 | 326 | 220 to 465 | |
| 1950–1959 | 140 | 3897 | 15 | 5.5 | 275 | 154 to 454 | |
| 1960–1971 | 146 | 3553 | 6 | 6.5 | 92 | 34 to 201 | |
| Duration of employment (y)* | 0.0001 | ||||||
| 1–4 | 482 | 5311 | 9 | 6.6 | 137 | 62 to 260 | |
| 5–9 | 314 | 3576 | 8 | 5.0 | 160 | 69 to 314 | |
| 10–19 | 201 | 2970 | 7 | 4.1 | 169 | 68 to 349 | |
| 20–32 | 106 | 2191 | 27 | 5.4 | 497 | 328 to 723 | |
| Time since first exposure (y)* | 0.12 | ||||||
| 0–9 | 482 | 4064 | 2 | 1.5 | 131 | 16 to 473 | |
| 10–19 | 430 | 4015 | 5 | 3.7 | 136 | 44 to 317 | |
| 20–29 | 366 | 3104 | 16 | 5.8 | 277 | 158 to 449 | |
| 30 or more | 257 | 2865 | 28 | 10.2 | 275 | 183 to 398 | |
| Cumulative hexavalent exposure, mg/m3-y‡ | 0.00002 | ||||||
| 0.00–0.19 | 2952 | 3 | 4.5 | 67 | 14 to 196 | ||
| 0.20–0.48 | 2369 | 8 | 4.4 | 184 | 79 to 362 | ||
| 0.49–1.04 | 3077 | 4 | 4.4 | 91 | 25 to 234 | ||
| 1.05–2.69 | 3220 | 16 | 4.4 | 365 | 208 to 592 | ||
| 2.70–23 | 2482 | 20 | 4.3 | 463 | 283 to 716 | ||
