Table 3. Associations of traumatic brain injury mortality from motor vehicle crashes with socio-demographic variables from multivariate negative binomial regression (China, 2006–2013).

Socio-demographic variable	TBI mortality from motor vehicle crashes by road user category
	Vehicle occupant			Motorcyclist			Pedal cyclist			Pedestrian			All others
	MRR	95% CI bounds		MRR	95% CI bounds		MRR	95% CI bounds		MRR	95% CI bounds		MRR	95% CI bounds
		Lower	Upper		Lower	Upper		Lower	Upper		Lower	Upper		Lower	Upper
Age group (reference = 25–44 years)
0–4 years	0.23*	0.18	0.29	0.05*	0.04	0.07	0.14*	0.09	0.22	0.51*	0.44	0.58	0.27*	0.20	0.38
5–14 years	0.13*	0.10	0.17	0.07*	0.06	0.08	0.29*	0.22	0.37	0.33*	0.29	0.38	0.23*	0.17	0.30
15–24 years	0.49*	0.42	0.57	0.74*	0.67	0.82	0.55*	0.45	0.68	0.60*	0.54	0.67	0.74*	0.61	0.89
45–64 years	1.03	0.90	1.18	0.92	0.84	1.02	2.60*	2.21	3.05	1.79*	1.63	1.96	1.28*	1.08	1.52
65–74 years	0.90	0.76	1.06	0.51*	0.45	0.59	3.59*	3.00	4.30	3.28*	2.97	3.61	1.68*	1.37	2.04
75 years and older	0.89	0.74	1.09	0.36*	0.30	0.43	3.44*	2.81	4.20	5.16*	4.68	5.70	2.05*	1.65	2.55
Location (reference = urban)
Rural	1.97*	1.78	2.19	3.16*	2.92	3.42	1.99*	1.77	2.24	1.72*	1.62	1.83	1.07	0.95	1.21
Sex (reference = female)
Male	3.20*	2.87	3.57	5.55*	5.10	6.03	2.45*	2.18	2.75	2.21*	2.08	2.34	2.92*	2.57	3.31
Year (reference = 2006)
2007	1.27*	1.03	1.57	1.26*	1.07	1.47	1.45*	1.13	1.85	1.33*	1.18	1.51	1.02	0.80	1.29
2008	1.69*	1.37	2.07	1.41*	1.21	1.65	1.64*	1.29	2.08	1.35*	1.20	1.53	1.11	0.88	1.40
2009	1.38*	1.13	1.70	1.57*	1.34	1.83	1.60*	1.26	2.04	1.42*	1.25	1.60	0.90	0.71	1.15
2010	1.58*	1.29	1.93	1.80*	1.55	2.10	1.76*	1.39	2.22	1.68*	1.49	1.89	1.32*	1.05	1.67
2011	1.65*	1.34	2.01	1.86*	1.60	2.16	1.92*	1.52	2.43	1.62*	1.44	1.83	1.00	0.79	1.26
2012	1.56*	1.27	1.91	1.68*	1.44	1.96	1.95*	1.54	2.45	1.53*	1.36	1.72	0.85	0.67	1.08
2013	1.42*	1.16	1.74	1.56*	1.34	1.82	1.57*	1.24	1.98	1.31*	1.16	1.48	0.65*	0.50	0.83

*p < 0.05.

MRR, mortality rate ratio; TBI, traumatic brain injury.