The National Institute for Occupational Safety and Health (NIOSH) styrene cohort: composition of the analysed study population as of 31 December 2011
| Characteristic | Entire analysed population (n=1678) | Potential low styrene exposure (n=1098)* | Potential high-styrene exposure (n=580) |
|---|---|---|---|
| Race/gender/vital status (deaths, % dead)† | |||
| Females, races other than Caucasian | 18 (3, 17%) | 6 (2, 33%) | 12 (1, 8%) |
| Females, Caucasian | 290 (67, 23%) | 93 (19, 20%) | 197 (48, 24%) |
| Males, races other than Caucasian | 56 (14, 25%) | 38 (9, 24%) | 18 (5, 28%) |
| Males, Caucasian | 1314 (514, 39%) | 961 (415, 43%) | 353 (99, 28%) |
| Total | 1678 (598, 36%) | 1098 (445, 41%) | 580 (153, 26%) |
| Median age at first employment (IQR) | 28.3 (22.8, 38.8) | 30.1 (23.8, 42.7) | 25.3 (21.2, 33.5) |
| Median years of employment (IQR) | 2.56 (1.49, 5.63) | 2.69 (1.49, 6.00) | 2.40 (1.49, 5.13) |
| Mean years of employment (SD(s)) | 4.34 (4.17) | 4.62 (4.55) | 3.83 (3.30) |
| Person-years at risk | 58 594 | 37 586 | 21 007 |
*Never worked in a high-styrene department.
†‘Alive’ includes five persons lost to follow-up before the National Death Index was initiated.