Table II.

Logistic regression model for likelihood of helmet use at time of off-road motorized vehicle crash

Variable	Odds ratio	95% Confidence interval	p
Vehicle type
ATV	1.0	–	–
Snowmachine	2.94	1.85–4.68	<0.0001
Motorbike	6.60	3.72–11.72	<0.0001
Age (per year increase)	1.08	1.01–1.15	0.025
Male sex	1.35	0.87–2.09	0.184
Ethnicity
White/other	1.0	–	–
Alaska Native/American Indian	0.17	0.11–0.27	<0.0001
Community type
Urban	1.0	–	–
Large rural	2.08	0.90–4.80	0.086
Small, isolated rural	0.55	0.35–0.88	0.012
Recent alcohol use	0.25	0.11–0.59	0.002
Recent drug use	1.17	0.45–2.99	0.749