Table 7.
Poisson regression models among long-term workers (3 months or longer) for selected underlying cause of death outcomes, NIOSH Capacitor Cohort.
| Cause of death | Rate ratio (95% confidence interval)a |
||||
|---|---|---|---|---|---|
| Continuous modelsb |
Categorical modelsc |
||||
| Unconstrainedd | Constrainedd | Estimated cumulative PCB exposure (unit-years) |
Unconstrainedd | Constrainedd | |
| Prostate cancer | 2.22 (1.06–4.80) | 1.73 (1.08–2.74) | 0 to <77 | 1 [reference] | 1 [reference] |
| 77 to <240 | 1.21 (0.58–2.49) | 1.20 (0.61–2.22) | |||
| 240 to <990 | 1.27 (0.63–2.58) | 1.27 (0.67–2.27) | |||
| 990 to <3200 | 1.52 (0.73–3.14) | 1.51 (0.78–2.75) | |||
| ≥3200 | 2.30 (1.14–4.67) | 2.28 (1.24–4.00) | |||
| Uterine cancer | 2.88 (0.62–15.2) | 1.70 (0.71–3.95) | 0 to <110 | 1 [reference] | 1 [reference] |
| 110 to <380 | 1.05 (0.30–3.51) | 1.08 (0.34–2.93) | |||
| 380 to <880 | 1.68 (0.48–5.62) | 1.72 (0.55–4.59) | |||
| 880 to <2500 | 1.28 (0.36–4.44) | 1.32 (0.41–3.59) | |||
| ≥2500 | 1.30 (0.35–4.67) | 1.34 (0.40–3.80) | |||
| Ovarian cancer | 1.07 (0.96–1.15) | 1.08 (0.98–1.16) | 0 to <120 | 1 [reference] | 1 [reference] |
| 120 to <250 | 3.29 (1.26–9.08) | 3.47 (1.46–7.89) | |||
| 250 to <870 | 1.52 (0.54–4.36) | 1.61 (0.64–3.75) | |||
| 870 to <3200 | 1.49 (0.52–4.32) | 1.57 (0.61–3.74) | |||
| ≥3200 | 2.57 (0.89–7.60) | 2.71 (1.03–6.58) | |||
| Stomach cancer | 4.79 (1.83–13.3) | 1.99 (1.05–3.71) | 0 to <110 | 1 [reference] | 1 [reference] |
| 110 to <650 | 1.48 (0.54–4.03) | 0.95 (0.39–2.09) | |||
| 650 to <1000 | 7.07 (2.66–19.0) | 4.43 (1.91–9.41) | |||
| 1000 to <2100 | 5.13 (1.98–13.6) | 3.20 (1.43–6.67) | |||
| ≥2100 | 3.04 (1.11–8.42) | 1.88 (0.80–4.07) | |||
| Multiple myeloma | 1.09 (0.99–1.17) | 1.09 (0.99–1.17) | 0 to <54 | 1 [reference] | 1 [reference] |
| 54 to <170 | 1.19 (0.42–3.45) | 1.28 (0.49–3.11) | |||
| 170 to <980 | 0.78 (0.28–2.26) | 0.84 (0.33–2.02) | |||
| 980 to <3300 | 1.27 (0.46–3.66) | 1.37 (0.54–3.27) | |||
| ≥3300 | 1.46 (0.48–4.47) | 1.59 (0.57–3.96) | |||
Rate ratios are adjusted for age and birth year; rate ratios for stomach cancer and multiple myeloma are additionally adjusted for gender. All models incorporate the best-fitting (based on model AIC) exposure lag period: 20 years for prostate, 10 years for uterine, 5 years for ovarian, 15 years for stomach, and 10 years for multiple myeloma.
For continuous model, the rate ratio is at 1000 unit-years of lagged exposure and based on the regression model with the best-fitting (based on model AIC) exposure transformation: natural logarithm (prostate, uterine, and stomach cancers) and identity (ovarian cancer and multiple myeloma).
For categorical models, cutpoints were selected based on quintiles of the lagged exposure distribution among cases.
The unexposed baseline rate (or low exposed for the categorical model) was either unconstrained or constrained to be 180 deaths per 100,000 for prostate cancer, 17 deaths per 100,000 for uterine cancer, 31 deaths per 100,000 for ovarian cancer, 30 deaths per 100,000 for stomach cancer, and 19 deaths per 100,000 for multiple myeloma, respectively.