Table 2. Median mesothelioma latency and crude time ratios for mesothelioma latency among British asbestos workers (1978–2005).
| Characteristic | No. of deaths | Person- years at risk | Median latency (years) | (95% CI) | Crude time ratio | (95% CI) | LR test |
|---|---|---|---|---|---|---|---|
| Total |
614 |
9280 |
22.8 |
(16.0–27.2) |
NA |
NA |
NA |
|
Sex |
|
|
|
|
|
|
P<0.001 |
| Male | 596 | 8995 | 22.2 | (15.5–27.0) | 1.00 | (ref) | |
| Female |
18 |
285 |
28.2 |
(14.0–34.1) |
1.26 |
(1.11–1.44) |
|
|
Main smoking status |
|
|
|
|
|
|
P=0.784 |
| Current | 344 | 5309 | 24.8 | (11.8–28.2) | 1.00 | (ref) | |
| Former | 168 | 2440 | 21.5 | (8.3–31.2) | 1.00 | (0.95–1.06) | |
| Never |
102 |
1531 |
19.4 |
(7.6–28.1) |
0.98 |
(0.91–1.05) |
|
|
Main occupation |
|
|
|
|
|
|
P=0.982 |
| Manufacturing | 203 | 3162 | 24.8 | (8.2–31.2) | 1.00 | (0.94–1.08) | |
| Removal | 200 | 2899 | 19.6 | (13.9–26.8) | 0.99 | (0.93–1.06) | |
| Other | 82 | 1305 | 25.5 | (6.2–30.2) | 1.01 | (0.92–1.10) | |
| Insulation |
129 |
1915 |
20.3 |
(2.2–31.3) |
1.00 |
(ref) |
|
|
Year of first exposure |
|
|
|
|
|
|
P<0.001 |
| <1940 | 40 | 303 | 48.1 | (44.6–50.1) | 1.00 | (ref) | |
| 1940−1949 | 96 | 1325 | 47.7 | (45.9–50.0) | 0.94 | (0.87–1.00) | |
| 1950−1959 | 216 | 3347 | 40.6 | (38.3–42.0) | 0.83 | (0.78–0.88) | |
| 1960−1969 | 145 | 2521 | 33.0 | (31.3–34.4) | 0.69 | (0.65–0.74) | |
| 1970−1979 | 79 | 1339 | 23.9 | (20.1–25.5) | 0.53 | (0.49–0.57) | |
| 1980+ |
38 |
445 |
11.1 |
(8.2–15.9) |
0.36 |
(0.34–0.39) |
|
|
Age at first exposure (years) |
|
|
|
|
|
|
P<0.001 |
| <20 | 246 | 3662 | 40.6 | (37.8–43.1) | 1.00 | (ref) | |
| 20−29 | 166 | 2604 | 34.5 | (31.0–37.4) | 0.93 | (0.88–0.98) | |
| 30−39 | 92 | 1512 | 30.2 | (25.0–32.8) | 0.82 | (0.77–0.87) | |
| 40−49 | 65 | 952 | 18.2 | (1.2–24.3) | 0.65 | (0.60–0.70) | |
| 50+ |
45 |
550 |
10.7 |
(7.7–15.2) |
0.61 |
(0.56–0.67) |
|
|
Duration of exposure (years) |
|
|
|
|
|
|
P<0.001 |
| <10 | 87 | 1415 | 17.0 | (13.7–20.3) | 1.00 | (ref) | |
| 10−19 | 115 | 2215 | 30.9 | (28.0–33.2) | 1.29 | (1.20–1.39) | |
| 20−29 | 164 | 2739 | 35.6 | (34.7–37.7) | 1.46 | (1.36–1.56) | |
| 30−39 | 162 | 2218 | 44.2 | (43.0–45.3) | 1.62 | (1.51–1.73) | |
| 40+ |
86 |
694 |
48.4 |
(45.8–50.2) |
1.70 |
(1.59–1.83) |
|
|
Mesothelioma type |
|
|
|
|
|
|
P=0.163 |
| Pleural | 301 | 4648 | 22.9 | (14.2–28.6) | 1.00 | (ref) | |
| Peritoneal | 132 | 1919 | 8.2 | (2.2–29.9) | 1.06 | (1.00–1.13) | |
| Pleural+peritoneal | 10 | 94 | 2.9 | (2.9–NE) | 0.92 | (0.77–1.10) | |
| Not specified |
171 |
2620 |
25.5 |
(18.2–28.9) |
1.01 |
(0.95–1.07) |
|
|
Died with asbestosis |
|
|
|
|
|
|
P=0.654 |
| No | 526 | 8286 | 24.9 | (18.2–28.3) | 1.00 | (ref) | |
| Yes | 88 | 994 | 7.7 | (2.2–20.6) | 1.02 | (0.94–1.10) |
Abbreviations: CI=confidence interval; LR test=likelihood-ratio test; NA=not applicable; NE=not estimable; ref=reference category.