Table 3. Multivariable logistic regression analysis on study outcomes by seat belt use and driving status.
| Variables | Total | Outcomes | Unadjusted | Adjusted* | |||
|---|---|---|---|---|---|---|---|
| No. | No. | % | OR | 95% CI | OR | 95% CI | |
| Primary outcome: Case-fatality | |||||||
| Seat belt use | |||||||
| Belted | 15,304 | 58 | 0.4 | 1.00 | 1.00 | ||
| Unbelted | 8,394 | 239 | 2.8 | 7.70 | 5.78-10.28 | 10.43 | 7.75-14.04 |
| Driving status | |||||||
| Driver | 9,233 | 77 | 0.8 | 1.00 | 1.00 | ||
| Non-driving passenger | 14,465 | 220 | 1.5 | 1.84 | 1.42-2.38 | 2.95 | 2.21-3.94 |
| Secondary outcome: Intracranial injury | |||||||
| Seat belt use | |||||||
| Belted | 15,304 | 257 | 1.7 | 1.00 | 1.00 | ||
| Unbelted | 8,394 | 350 | 4.2 | 2.55 | 2.16-3.00 | 2.68 | 2.25-3.19 |
| Driving status | |||||||
| Driver | 9,233 | 229 | 2.5 | 1.00 | 1.00 | ||
| Non-driving passenger | 14,465 | 378 | 2.6 | 1.06 | 0.89-1.25 | 1.34 | 1.11-1.62 |
| Tertiary outcome: Clinically important injury | |||||||
| Seat belt use | |||||||
| Belted | 15,304 | 2,216 | 14.5 | 1.00 | 1.00 | ||
| Unbelted | 8,394 | 2,129 | 25.4 | 2.01 | 1.88-2.15 | 2.19 | 2.04-2.36 |
| Driving status | |||||||
| Driver | 9,233 | 1,557 | 16.9 | 1.00 | 1.00 | ||
| Non-driving passenger | 14,465 | 2,788 | 19.3 | 1.18 | 1.10-1.26 | 1.41 | 1.30-1.53 |
*Adjusted for seat belt use, driving status, age, gender, time of injury, day of injury, alcohol use, and past medical history (hypertension and diabetes). OR, odds ratio; CI, confidence interval.