Table II. Distribution of covariates across exposure categories.
| <48 hours (n=620,487) | 48-59 hours (n=233,221) | ≥60 hours (n=112,374) | Total (n=966,082) | |
|---|---|---|---|---|
| Familiarity (past 8 weeks) | ||||
| Median (P25-75) | 7 (1-20) | 8 (1-19) | 5 (1-17) | 7 (1-19) |
| Hours of recovery | ||||
| Median (P25-P75) | 19 (12-84) | 12 (12-36.5) | 12 (11.5-24) | 16 (12-60) |
| Number of shifts in the month | ||||
| Mean (SD) | 12.1 (4.6) | 13.6 (4.0) | 16.0 (4.8) | 12.9 (4.7) |
| Proportion night hours | ||||
| Mean (SD) | 0.25 (0.29) | 0.29 (0.27) | 0.31 (0.26) | 0.27 (0.28) |
|
| ||||
| Unique employees | 4,382 | 3,562 | 2,810 | 4,382 |
| Part-time employees | 4,380 | 3,332 | 1,551 | 4,380 |
|
| ||||
| Injuries (n (%)) | 637 (0.10) | 202 (0.09) | 111 (0.10) | 950 (0.10) |
| Injuries with work restriction only | 137 (0.02) | 54 (0.02) | 21 (0.02) | 212 (0.02) |
| Injuries requiring time away from work | 91 (0.01) | 22 (0.01) | 8 (0.01) | 121 (0.01) |