Summary of patient demographics and toxicology screen prior to matching
| No helmet (n=3150) | Helmet (n=3699) | P value | |
| Age | 43.0±15.1 | 38.9±16.0 | <0.001 |
| Sex (male) | 2728 (86.6%) | 3228 (87.3%) | 0.416 |
| Race | <0.001 | ||
| Black | 83 (2.6%) | 198 (5.4%) | |
| Hispanic | 476 (15.1%) | 448 (12.1%) | |
| Other | 115 (3.7%) | 138 (3.7%) | |
| White | 2476 (78.6%) | 2915 (78.8%) | |
| Comorbidities (1+) | 1567 (49.7%) | 1499 (40.5%) | <0.001 |
| Alcohol above legal limit | 545 (17.3%) | 203 (5.5%) | <0.001 |
| Illegal drug screen | 613 (19.5%) | 462 (12.6%) | <0.001 |
| Payer | <0.001 | ||
| Medicaid/AHCCCS | 845 (26.8%) | 633 (17.1%) | |
| Medicare | 247 (7.8%) | 217 (5.9%) | |
| Other | 312 (9.9%) | 483 (13.1%) | |
| Private | 1340 (42.5%) | 1921 (51.9%) | |
| Self-pay | 406 (12.9%) | 445 (12.0%) |
AHCCCS, Arizona Health Care Cost Containment System.