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Table 1 Description of the study population by motorcycle helmet law

From: Motorcycle helmet effectiveness in reducing head, face and brain injuries by state and helmet law

Characteristic

Partial helmet law

Universal helmet law

P-value*

Number of motorcycle operators

N = 28,207

N = 45,552

 

Helmet used

42 %

88 %

<0.01

Age (Median)

37

36

0.52

Male

93 %

93 %

0.77

Single Vehicle Crash

39 %

45 %

<0.01

Crash at Intersection

36 %

40 %

<0.01

Night time

18 %

17 %

<0.01

Speed relateda

10 %

17 %

<0.01

Suspicion of alcohol or drugsa

9 %

5 %

<0.01

Rural locationa

17 %

31 %

<0.01

Poor Surface Conditions

6 %

7 %

<0.01

Crash record linked to a medical record

55 %

58 %

<0.01

Died at the scene

3 %

3 %

0.62

  1. a Available for only a subset of the 11 included states: speed related (10), suspicion of alcohol or drugs (9), and rural location (8)
  2. *P-value from a Median regression model with bootstrapped standard error (age), or likelihood ratio test of homogeneity (all others)