TABLE 1—
Crash-Involved Motorcyclist (Operators and Passengers) Characteristics for the 12 Months Before (April 13, 2011, to April 12, 2012) and 12 Months After (April 13, 2012, to April 12, 2013) the Partial Repeal of Michigan’s Universal Motorcycle Helmet Law
| Characteristic | Before Repeala (n = 3594; 49.7%), Mean ±SD or No. (%) | After Repealb (n = 3641; 50.3%), Mean ±SD or No. (%) | OR (95% CI) |
| Sociodemographics | |||
| Age, y | 42.5 ±14.7 | 41.8 ±15.0 | 1.00 (1.00, 1.01)c |
| Male gender | 3087 (85.9) | 3111 (85.4) | 1.04 (0.91, 1.18) |
| Position: operator | 3311 (92.1) | 3346 (92.9) | 1.03 (0.87, 1.22) |
| Crash characteristics | |||
| Speed limit, mph | 45.6 ±12.7 | 44.8 ±12.5 | 1.01 (1.00, 1.01)d |
| Helmet use: yes | 3369 (93.7) | 2587 (71.1) | 6.10 (5.24, 7.11) |
| Crash at intersection | 1134 (31.6) | 1219 (33.5) | 0.92 (0.83, 1.01) |
| Medical characteristics: alcohol intoxication (BAC ≥ 80 mg/dL) | 90 (2.5) | 114 (3.1) | 0.80 (0.60, 1.05) |
| Health-related outcomes | |||
| Fatal injuries | 117 (3.3) | 116 (3.2) | 1.02 (0.79, 1.33) |
| Serious injuries, KAe | 710 (19.8) | 743 (20.4) | 0.96 (0.86, 1.08) |
| All fatal and nonfatal injuries, KABCe | 2832 (78.8) | 2873 (78.9) | 0.99 (0.89, 1.11) |
Notes. BAC = blood alcohol content; CI = confidence interval; OR = odds ratio.
a
April 13, 2011, to April 12, 2012.
b
April 13, 2012, to April 12, 2013.
c
OR for age without rounding is 1.00314 (95% CI = 1.00003, 1.00625).
d
OR for speed limit without rounding is 1.00468 (95% CI = 1.00468, 1.00837).
e
KABCO scale = K: fatal injury; A: incapacitating injury; B: nonincapacitating injury; C: possible injury; O: uninjured, property damage only.