Table 1.
Odds RatiosA and 95% Confidence Intervals (CI) for Multiple Myeloma and Occupational Exposure to 1,1,1-trichloroethane (TCA).
| Primary Analysis | Reanalysis: Jobs Assessed with Low Confidence Considered Unexposed |
||||||
|---|---|---|---|---|---|---|---|
| Controls (n=481) |
Cases (n=180) |
Odds ratio (95% CI) |
Controls (n=481) |
Cases (n=180) | Odds ratio (95% CI) |
||
| Ever exposed B | 65 (14%) | 36 (20%) | 1.8 (1.1–2.9) | Ever exposed B | 23 (4.8%) | 17 (9.4%) | 2.2 (1.1–4.4) |
| Duration | Duration | ||||||
| Unexposed | 416 (86%) | 144 (80%) | Referent | Unexposed | 458 (95%) | 163 (91%) | Referent |
| 1–3 years | 16 (3.3%) | 7 (3.9%) | 1.6 (0.6–4.3) | 1–5 years | 9 (1.8%) | 5 (2.8%) | 1.8 (0.6–5.7) |
| 4–8 years | 16 (3.3%) | 11 (6.1%) | 2.3 (1.0–5.3) | 6–16 years | 3 (0.6%) | 6 (3.3%) | 6.7 (1.5–29) |
| 9–21 years | 15 (3.1%) | 11 (6.1%) | 1.9 (0.8–4.5) | 17–25 years | 7 (1.5%) | 4 (2.2%) | 1.6 (0.4–6.0) |
| 22–45 years | 18 (3.7%) | 7 (3.9%) | 1.3 (0.5–3.3) | 26–45 years | 4 (0.8%) | 2 (1.1%) | 1.3 (0.2–7.4) |
| p-trend 0.17 | p-trend 0.27 | ||||||
| Cumulative exposure C,D | Cumulative exposure C,D | ||||||
| Unexposed | 416 (86%) | 144 (80%) | Referent | Unexposed | 458 (95%) | 163 (91%) | Referent |
| 1–53 | 17 (3.5%) | 7 (3.9%) | 1.7 (0.7–4.4) | 1–378 | 5 (1.0%) | 5 (2.8%) | 3.7 (1.0–13) |
| 54–605 | 16 (3.3%) | 10 (5.6%) | 2.2 (0.9–5.3) | 379–1938 | 6 (1.3%) | 2 (1.1%) | 1.1 (0.2–5.8) |
| 606–3750 | 16 (3.3%) | 8 (4.4%) | 1.4 (0.5–3.4) | 1939–10012 | 6 (1.3%) | 6 (3.3%) | 3.0 (0.9–10) |
| 3751–57000 | 16 (3.3%) | 11 (6.1%) | 1.9 (0.8–4.4) | 10013–57000 | 6 (1.3%) | 4 (2.2%) | 1.5 (0.4–5.8) |
| p-trend 0.19 | p-trend 0.33 | ||||||
| 10-year-lagged cumulative exposure C,D | 10-year-lagged cumulative exposure C,D | ||||||
| Unexposed | 417 (87%) | 147 (82%) | Referent | Unexposed | 459 (95%) | 164 (91%) | Referent |
| 1–49 | 16 (3.3%) | 7 (3.9%) | 1.8 (0.7–4.6) | 1–303 | 6 (1.3%) | 5 (2.8%) | 3.1 (0.9–11) |
| 50–342 | 16 (3.3%) | 7 (3.9%) | 1.5 (0.6–3.3) | 304–1690 | 5 (1.0%) | 0 | NA |
| 343–2781 | 16 (3.3%) | 8 (4.4%) | 1.3 (0.5–3.3) | 1691–4500 | 6 (1.3%) | 5 (2.8%) | 2.3 (0.6–8.0) |
| 2782–49500 | 16 (3.3%) | 11 (6.1%) | 1.8 (0.8–4.1) | 4501–49500 | 5 (1.0%) | 6 (3.3%) | 2.8 (0.8–9.9) |
| p-trend 0.21 | p-trend 0.07 | ||||||
A
All models adjusted for age, race, study site, gender, and years of education.
B
Ever exposed defined as having at least 1 job with a probability score of 2 for exposure to TCA and all jobs with a probability score of <2 were considered as unexposed.
C
Some participants were unexposed in the cumulative scores but not the ever/never and duration analyses because they were exposed <15 minutes per week and therefore had a frequency of 0.
D
Cumulative score calculated by multiplying the midpoint of the intensity (in ppm) by the midpoint of the frequency (in hours/week) by the number of years worked in each exposed job.