Measures of Sleepiness, Quality, and Quantity of Recent Sleep and Risk of Injury, Controlling for Activity, Location, and Drinking in the Previous 6 Hours
| Case-Crossover Analyses | Case-Control Analyses | |
|---|---|---|
| Self-perceived sleepiness at injury or matched time | ||
| Per unit on a 0 to 12 scale | 0.82 (0.78 to 0.86) | 0.76 (0.73 to 0.80) |
| Dichotomous: >0 vs 0 | 0.56 (0.45 to 0.70) | 0.29 (0.24 to 0.37) |
| Trichotomous: 1 to 3 vs 0 | 0.67 (0.53 to 0.84) | 0.49 (0.38 to 0.63) |
| 4 to 12 vs 0 | 0.30 (0.22 to 0.42) | 0.16 (0.12 to 0.21) |
| Usual sleep | ||
| Quality (per point on a 5-point ordinal scale) | ||
| Quantity (per hour) | ||
| Quantity in past 7 days compared with your usual (per point on a 5-point ordinal scale) | ||
| Quality in past 7 days compared with usual | 0.87 (0.76 to 1.01) | |
| Sleep in past 48 hours | ||
| Sleep in past 24 hours compared with the 24 hours before that | 1.01 (0.97 to 1.05) | |
| Last episode of sleep compared with the previous one | 1.00 (0.96 to 1.04) | |
| Trichotomous, past 24 hours compared with previous 24: | ||
| Less than 5 hours compared with 5 to 9 hours | 1.14 (0.81 to 1.61) | |
| 10 hours or more compared with 5 to 9 hours | 1.01 (0.78 to 1.31) | |
| Sleep in past 24 hours compared with usual quantity (per hour) | 1.01 (0.96 to 1.05) |
OR (95% CI).