Table 4.
Summary of multivariable Cox proportional hazards categorical regression modelling for Caucasian male Fernald workers (mortality through 2004) for outcomes of a priori interest with at least 25 cases
| Outcome | Model | Organ dose (µGy)* | EST | PL 95% CI‡ | External dose (mGy) | EST | PL 95% CI‡ | Radon decay products (WLM) | EST | PL 95% CI‡ |
|---|---|---|---|---|---|---|---|---|---|---|
| MN lung | M1 | Unexposed | Ref | Unexposed | Ref | 0.0–0.51 | Ref | |||
| >0.0–14 | 0.17 | (−0.25 to 0.79) | >0.0–2.0 | −0.049 | (−0.36 to 0.34) | >0.51–5.4 | −0.22 | (−0.55 to 0.13) | ||
| >14–170 | 0.0056 | (−0.38 to 0.56) | >2.0–9.0 | −0.018 | (−0.31 to 0.30) | >5.4–20 | −0.30 | (−0.70 to 0.089) | ||
| >170–1500 | −0.21 | (−0.54 to 0.25) | >9.0–40 | −0.084 | (−0.41 to 0.24) | >20–42 | −0.16 | (−0.58 to 0.29) | ||
| >1500 | 0.027 | (−0.37 to 0.60) | >40 | 0.17 | (−0.19 to 0.64) | >42 | −0.16 | (−0.60 to 0.31) | ||
| M2 | ERR (per 100 µGy) | 0.0022 | (−0.00093 to 0.0070) | ERR (per 100 mGy) | 0.13 | (−0.26 to 0.68) | ERR (per 10 WLM) | −0.0070 | (−0.013 to 0.0068) | |
| M3 | ERR (per 100 µGy), 1%§ | 0.00064 | (−0.0044 to 0.0073) | ERR (per 100 mGy), 1% | 0.093 | (−0.40 to 0.75) | ERR (per 10 WLM), 1% | 0.0011 | (−0.012 to 0.023) | |
| M4 | HR (at 100 µGy) | 1.002 | (0.999 to 1.005) | HR (at 100 mGy) | 1.2 | (0.76 to 1.7) | HR (at 10 WLM) | 0.999 | (0.97 to 1.004) | |
| COPD | M1 | 0.0–24 | Ref | Unexposed | Ref | 0.0–4.3 | Ref | |||
| >24–150 | 0.71 | (−0.36 to 2.6) | >0.0–2.0 | 0.21 | (−0.69 to 2.2) | >4.3–14 | 0.57 | (−0.47 to 2.4) | ||
| >150–650 | 0.50 | (−0.40 to 2.3) | >2.0–16 | −0.50 | (−0.96 to 0.51) | >14–30 | 0.46 | (−0.44 to 2.2) | ||
| >650–2100 | 0.70 | (−0.37 to 2.8) | >16–49 | −0.31 | (−1.5 to 1.2) | >30–45 | 1.3 | (−0.05 to 4.1) | ||
| >2100 | 0.36 | (−0.87 to 2.3) | >49 | 0.58 | (−0.89 to 3.2) | >45 | 0.36 | (−0.64 to 2.1) | ||
| M2 | ERR (per 100 µGy) | −0.0062 | (−0.0065 to 0.000062) | ERR (per 100 mGy) | 0.54 | (−0.00025 to 1.4) | ERR (per 10 WLM) | −0.018 | (−0.018 to 0.0027) | |
| M3 | ERR (per 100 µGy), 1% | 0.000048 | (−0.0059 to 0.013) | ERR (per 100 mGy), 1% | 0.45 | (−0.38 to 1.8) | ERR (per 10 WLM), 1% | −0.017 | (−0.017 to 0.025) | |
| M4 | HR (per 100 µGy) | 0.996 | (0.99 to 1.002) | HR (per 100 mGy) | 1.7 | (0.93 to 2.8) | HR (at 10 WLM) | 0.99 | (0.96 to 1.01) | |
| MN intestine | M1 | 0.0–0.01 | Ref | Unexposed | Ref | |||||
| >0.01–0.98 | −0.39 | (−0.78 to 0.49) | >0.0–3.0 | −0.20 | (−0.70 to 0.74) | |||||
| >0.98–4.4 | 0.24 | (−0.51 to 1.9) | >3.0–9.1 | 0.38 | (−0.38 to 1.8) | |||||
| >4.4–36 | −0.24 | (−0.78 to 0.91) | >9.1–28 | −0.18 | (−1.2 to 1.0) | |||||
| >36 | 1.7 | (0.17 to 5.7) | >28 | −0.23 | (−1.0 to 0.73) | |||||
| M2 | ERR (per 100 µGy) | NS | ERR (per 100 mGy) | NS | ||||||
| M3 | ERR (per 100 µGy), 1% | NS | ERR (per 100 mGy), 1% | NS | ||||||
| M4 | HR (at 100 µGy) | 2 | (1.05 to 3.2) | HR (at 100 mGy) | 0.57 | (0.18 to 1.4) | ||||
| MN pancreas | M1 | 0.0–0.13 | Ref | 0.0–<2.0 | Ref | |||||
| >0.13–1.5 | 0.44 | (−0.36 to 2.2) | 2.0–<7.0 | 0.36 | (−0.54 to 2.3) | |||||
| >1.5 | 0.46 | (−0.38 to 2.1) | ≥7.0 | −0.52 | (−0.96 to 0.52) | |||||
| M2 | ERR (per 100 µGy) | NS | ERR (per 100 mGy) | NS | ||||||
| M3 | ERR (per 100 µGy), 1% | NS | ERR (per 100 mGy), 1% | NS | ||||||
| M4 | HR (at 100 µGy) | 0.61 | (0.015 to 3.5) | HR (at 100 mGy) | 0.59 | (0.11 to 1.9) | ||||
| NHL | M1 | 0.0–0.26 | Ref | Unexposed | Ref | |||||
| >0.26–7.2 | 0.19 | (−0.65 to 4.1) | >0.0–9.9 | 0.21 | (−0.59 to 3.9) | |||||
| >7.2 | 0.090 | (−0.79 to 4.3) | >9.9 | 0.42 | (−1.3 to 4.9) | |||||
| M2 | ERR (per 100 µGy) | NS | ERR (per 100 mGy) | NS | ||||||
| M3 | ERR (per 100 µGy), 1% | NS | ERR (per 100 mGy), 1% | NS | ||||||
| M4 | HR (at 100 µGy) | 1.2 | (0.89 to 1.5) | HR (at 100 mGy) | 0.77 | (0.14 to 2.5) | ||||
| Leukaemia (excluding CLL) | M1 | 0.0–0.22 | Ref | Unexposed | Ref | |||||
| >0.22–2.8 | 0.095 | (−0.55 to 1.4) | >0.0–7.0 | −0.47 | (−0.89 to 0.25) | |||||
| >2.8 | −0.20 | (−0.70 to 0.61) | >7.0 | −0.36 | (−0.89 to 0.57) | |||||
| M2 | ERR (per 100 µGy) | NS | ERR (per 100 mGy) | NS | ||||||
| M3 | ERR (per 100 µGy), 1% | NS | ERR (per 100 mGy), 1% | NS | ||||||
| M4 | HR (at 100 µGy) | 0.18 | (0.012 to 0.80) | HR (at 100 mGy) | 2.8 | (0.87 to 6.0) | ||||
| MN stomach | M1 | 0.0–0.05 | Ref | 0.0–1.0 | Ref | |||||
| >0.05–6.2 | −0.51 | (−0.93 to 0.86) | >1.0–3.0 | 1.1 | (−0.20 to 4.9) | |||||
| >6.2 | 0.62 | (−0.66 to 4.8) | >3.0 | 0.15 | (−0.76 to 2.0) | |||||
| M2 | ERR (per 100 µGy) | 0.041 | (−0.20 to 5.6) | ERR (per 100 mGy) | 1.0 | (−0.31 to 6.1) | ||||
| M3 | ERR (per 100 µGy), 1% | NS | ERR (per 100 mGy), 1% | NS | ||||||
| M4 | HR (at 100 µGy) | 1.002 | (0.16 to 2.5) | HR (at 100 mGy) | 1.8 | (0.42 to 4.9) |
Target organ varied by outcome (see online supplementary table S5); estimates of cumulative exposure incorporate a 10-year lag period for non-leukaemia outcomes (2-year lag period for leukaemia excluding CLL).
All multivariable models are adjusted for pay code (hourly/salaried) and birth year (spline terms) and consider all radiologic exposures simultaneously. Model M1 is linear ERR with a categorical treatment of exposure; model M2 is linear ERR with continuous treatment of exposure; model M3 is like model M2, but incorporates a 1% trim; and model M4 is log-linear with a continuous treatment of exposure. Models of lung cancer and COPD are additionally adjusted for occupational exposure to acids; models of NHL are additionally adjusted for occupational exposure to trichloroethylene.
Profile likelihood 95% CIs.
1% denotes a 1% trimmed model which excluded risk sets for which the case exceeded the 99th percentile and all controls that exceed the 99th percentile.
CLL, chronic lymphocytic leukaemia; COPD, chronic obstructive pulmonary disease; ERR, excess relative risk; EST, estimate; MN, malignant neoplasm; NE, not estimable; NS, no solution found; NHL, non-Hodgkin’s lymphoma; RDP, Radon decay products; WLM, working-level months.