Table 3.
Individual-level and plant-level predictors of acute traumatic occupational injury in an aluminium manufacturing cohort: individual-level and multilevel models.
| Variable | Model† |
|||||||
|---|---|---|---|---|---|---|---|---|
| Model 1: individual-level model (N=22 681 workers) |
Model 2: random intercepts model (N=22 681 workers, 56 plants) |
Model 3: individual-level model |
Model 4: random intercepts model |
|||||
| Sex | ||||||||
| Female | 0.94 | (0.82 to 1.09) | 1.44 | (1.23 to 1.67)*** | 1.51 | (1.31 to 1.75)*** | 1.44 | (1.23 to 1.67)*** |
| Male | 1.0 | – | 1.0 | – | 1.0 | – | 1.0 | – |
| Race | ||||||||
| Black | 1.04 | (0.89 to 1.20) | 1.10 | (0.94 to 1.31) | 0.94 | (0.81 to 1.10) | 1.07 | (0.91 to 1.27) |
| Hispanic | 1.27 | (1.08 to 1.49)** | 1.28 | (1.06 to 1.54)** | 1.45 | (1.22 to 1.71)*** | 1.30 | (1.08 to 1.57)** |
| Asian | 0.68 | (0.47 to 0.98)* | 0.83 | (0.55 to 1.25) | 0.93 | (0.63 to 1.37) | 0.85 | (0.57 to 1.28) |
| White | 1.0 | – | 1.0 | – | 1.0 | – | 1.0 | – |
| Age (10-year groupings) | 0.93 | (0.88 to 0.99)* | 0.98 | (0.92 to 1.04) | 1.02 | (0.96 to 1.08) | 0.99 | (0.93 to 1.05) |
| Time since hire (years) | ||||||||
| <1 | 2.73 | (2.28 to 3.28)*** | 2.41 | (1.98 to 2.94)*** | 2.67 | (2.20 to 3.25)*** | 2.44 | (2.00 to 2.97)*** |
| 1–2 | 1.18 | (0.91 to 1.53) | 2.00 | (1.52 to 2.64)*** | 2.15 | (1.64 to 2.83)*** | 2.08 | (1.57 to 2.75)*** |
| 3–5 | 1.64 | (1.32 to 2.04)*** | 1.60 | (1.28 to 2.01)*** | 1.63 | (1.28 to 2.00)*** | 1.64 | (1.31 to 2.06)*** |
| 6–10 | 1.59 | (1.34 to 1.88)*** | 1.63 | (1.36 to 1.95)*** | 1.71 | (1.43 to 2.05)*** | 1.65 | (1.38 to 1.98)*** |
| 11–20 | 1.21 | (1.02 to 1.43)* | 1.29 | (1.08 to 1.53)** | 1.22 | (1.08 to 1.45)* | 1.29 | (1.08 to 1.54)** |
| >20 | 1.0 | – | 1.0 | – | 1.0 | – | 1.0 | – |
| Job grade (quintiles) | 1.37 | (1.31 to 1.43)*** | 0.91 | (0.85 to 0.97)** | 0.96 | (0.91 to 1.02) | 0.87 | (0.81 to 0.94)** |
| Unionised plant (Y/N) | 0.68 | (0.54 to 0.85)*** | 0.40 | (0.17 to 0.95)* | ||||
| Plant type | ||||||||
| Rigid packaging | 0.70 | (0.60 to 0.80)*** | 0.87 | (0.19 to 3.92) | ||||
| Casting | 0.09 | (0.07 to 0.13)*** | 0.08 | (0.03 to 0.22)*** | ||||
| Closure systems | 0.03 | (0.01 to 0.08)*** | 0.03 | 0.005, 1.21*** | ||||
| Engineered products | 0.46 | (0.38 to 0.54)*** | 0.23 | (0.09 to 0.62)** | ||||
| Fastener | 0.05 | (0.03 to 0.08)*** | 0.05 | (0.01 to 0.19)*** | ||||
| Consumer products | 0.41 | (0.33 to 1.51)*** | 0.44 | (0.15 to 1.25) | ||||
| Rolled products | 0.04 | (0.03 to 0.07)*** | 0.02 | 0.004, 0.14*** | ||||
| Smelter | 1.0 | – | 1.0 | – | ||||
| Satisfaction scale (tertiles) | 0.68 | (0.57 to 0.80)*** | 0.94 | (0.46 to 1.95) | ||||
| Work environment scale (tertiles) | 0.82 | (0.69 to 0.98)* | 0.49 | (0.22 to 1.22) | ||||
| Supervisor scale (tertiles) | 0.43 | (0.37 to 0.50)*** | 0.70 | (0.25 to 2.02) | ||||
| Stress scale (tertiles) | 0.60 | (0.47 to 0.76)*** | 0.50 | (0.28 to 0.90)* | ||||
†Results are presented in the format of incidence rate ratio (95% CI).
*p<0.05; **p<0.01; ***p<0.001.