Helmet use among Alaskan children involved in off-road motorized vehicle crashes

Figures & data

Fig. 1.  Prevalence of CNS injury after off-road motorized vehicle crash among Alaskan children by ethnicity.

Table I. Descriptive statistics for paediatric off-road motorized vehicle crashes, by helmet status*

	Helmet (N=301)	No helmet (N=352)	Helmet status unknown (N=268)
Age, years	15 (13–16)	14 (11–16)	14 (11–16)
Female sex	68 (23)	134 (38)	69 (26)
Ethnicity
Alaska Native/American Indian	81 (27)	262 (74)	124 (46)
White	197 (65)	79 (22)	130 (49)
Other/unknown	23 (8)	11 (3)	14 (5)
Community type
Urban	143 (48)	69 (20)	97 (36)
Large rural	31 (10)	12 (3)	11 (4)
Small, isolated rural	127 (42)	271 (77)	160 (60)
Vehicle type
All-terrain vehicle (ATV)	112 (37)	234 (66)	138 (52)
Snowmachine	86 (29)	92 (26)	76 (28)
Motorbike	103 (24)	26 (7)	54 (20)
Injury Severity Score (ISS)	9 (4–9)	6 (4–10)	4 (4–9)
ISS≥10	72 (24)	94 (27)	31 (12)
Central nervous system (CNS) injury	43 (14)	117 (33)	32 (12)
Any thoracoabdominal/pelvic/vascular injury	68 (23)	29 (8)	41 (15)
Thoracic	34 (11)	19 (5)	12 (4)
Abdominal – solid organ	36 (12)	9 (3)	28 (10)
Abdominal – other	3 (1)	2 (1)	0
Pelvic fracture	14 (5)	13 (4)	7 (3)
Vascular injury	5 (2)	2 (1)	2 (1)
Combined CNS & thoracoabdominal/pelvic/vascular injury	6 (2)	11 (3)	2 (1)
Death	4 (1)	6 (2)	3 (1)
Death or permanent disability	12 (4)	21 (6)	5 (2)

*Categorical variables presented as N (%); continuous variables as median (interquartile range).

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

Table III. Logistic regression model for likelihood of CNS injury after off-road motorized vehicle crash

Variable	Odds ratio	95% Confidence interval	p
Helmet use	0.28	0.18–0.44	<0.001
Vehicle type
ATV	1.0	–	–
Snowmachine	0.60	0.39–0.93	0.02
Motorbike	0.75	0.44–1.29	0.30
Age (per year increase)	0.98	0.93–1.03	0.17
Male sex	0.96	0.65–1.41	0.84
Ethnicity
Alaska Native/American Indian	1.0	–	–
White/other	1.07	0.68–1.68	0.78
Community type
Urban	1.0	–	–
Large rural	1.10	0.52–2.34	0.81
Small, isolated rural	0.75	0.47–1.19	0.22
Recent alcohol use	0.94	0.48–1.83	0.85
Recent drug use	6.58	2.92–14.92	<0.001

Table IV. Logistic regression model for likelihood of death or permanent disability after off-road motorized vehicle crash

Variable	Odds ratio	95% Confidence interval	p
Helmet use	0.26	0.10–0.67	0.006
Vehicle type
ATV	1.0	–	–
Snowmachine	0.49	0.14–1.76	0.27
Motorbike	3.41	1.28–9.10	0.02
Age (per year increase)	1.05	0.92–1.20	0.46
Male sex	0.47	0.21–1.07	0.07
Ethnicity
White/other	1.0	–	–
Alaska Native/American Indian	0.44	0.17–1.11	0.08
Community type
Urban	1.0	–	–
Large rural	1.70	0.42–6.90	0.46
Small, isolated rural	0.97	0.38–2.46	0.94
Recent alcohol use	0.71	0.17–2.92	0.64
Recent drug use	2.00	0.55–7.25	0.29