Table 2.
Standardized mortality ratiosa and 95% confidence intervals for mesothelioma, stratified by duration of employment, job type, period of hire, calendar period, and facility of longest employment duration in pooled cohort of workers from five United States nuclear facilities, follow-up through 2016
| Characteristic | Observed | SMR (95% CI) |
|---|---|---|
| Duration of employment | ||
| <5 years | 31 | 2.30 (1.57, 3.27) |
| 5 to <15 years | 26 | 2.37 (1.55, 3.48) |
| 15 to <25 years | 21 | 2.51 (1.55, 3.84) |
| ≥25 years | 70 | 3.33 (2.60, 4.21) |
| Job type | ||
| Professional and technical | 31 | 1.19 (0.81, 1.69) |
| Skilled non-manual | 6 | 1.55 (0.57, 3.38) |
| Skilled manual | 100 | 5.87 (4.78, 7.14) |
| Partly skilled and unskilled | 7 | 1.29 (0.52, 2.65) |
| Missing | <5 | 2.91 (0.78, 7.45) |
| Period of hire | ||
| <1955 | 61 | 3.03 (2.31, 3.89) |
| 1955 to <1965 | 57 | 3.43 (2.60, 4.44) |
| 1965 to <1975 | 19 | 2.15 (1.29, 3.35) |
| 1975 to <1985 | 9 | 1.38 (0.63, 2.61) |
| 1985+ | <5 | 1.24 (0.14, 4.49) |
| Calendar periodb | ||
| <2000 | 8 | 2.91 (1.25, 5.74) |
| 2000 to <2010 | 85 | 2.80 (2.24, 3.47) |
| 2010+ | 55 | 2.66 (2.00, 3.46) |
| Facility | ||
| Portsmouth Naval Shipyard | 48 | 8.62 (6.36, 11.44) |
| Hanford site | 10 | 1.15 (0.55, 2.12) |
| Oak Ridge National Laboratory | 35 | 2.38 (1.66, 3.31) |
| Savannah River site | 12 | 1.19 (0.61, 2.07) |
| Idaho National Laboratory | 43 | 2.92 (2.11, 3.94) |
SMR, standardized mortality ratio.
a
Standardized by sex, 5-year age group, and 5-year calendar period.
b
Deaths are limited to mesotheliomas coded into the ICD-10 revision mesothelioma category, which began in 1999.