Table 4

Poisson regression analysis of RTC fatality rates by age and road user type

Group	Model	IRR	95% CI	P value	Adjusted IRR	95% CI	P value
Age group 1–14 years
All traffic-related RTC fatalities	Year	0.92	0.90 to 0.93	<0.001	0.96	0.9 to 0.98	<0.01
	Interv year 1993	1.39	1.01 to 1.9	<0.05	1.01	0.77 to 1.35	0.9
	Interv year 2002	0.52	0.39 to 0.72	<0.001	0.52	0.40 to 0.68	<0.001
	Interv year 2006	0.71	0.45 to 1.11	0.1	1.1	0.75 to 1.50	0.8
	Interv year 2010	0.57	0.34 to 0.96	<0.05	0.55	0.31 to 0.98	<0.05
Pedestrians	Year	0.92	0.90 to 0.93	<0.001	0.94	0.90 to 0.97	<0.01
	Interv year 1993	1.18	0.90 to 1.55	0.2	1.01	0.74 to 1.36	0.9
	Interv year 2002	0.59	0.39 to 0.90	<0.05	0.49	0.33 to 0.72	<0.001
	Interv year 2006	1.13	0.64 to 1.99	0.6	1.67	0.92 to 3.05	0.1
	Interv year 2010	0.75	0.48 to 1.18	0.2	0.60	0.35 to 1.03	0.1
Vehicle occupants	Year	0.94	0.93 to 0.95	<0.001	1.01	0.95 to 1.06	0.6
	Interv year 1993	1.61	1.12 to 2.32	<0.05	0.97	0.68 to 1.36	0.8
	Interv year 2002	0.42	0.26 to 0.67	<0.001	0.45	0.29 to 0.69	<0.001
	Interv year 2006	0.52	0.30 to 0.87	<0.05	0.71	0.42 to 1.19	0.2
	Interv year 2010	0.58	0.34 to 1.02	0.1	0.60	0.32 to 1.14	0.1
Age group 15–19 years
All traffic-related RTC fatalities	Year	0.95	0.94 to 0.97	<0.001	1.001	0.96 to 1.04	1.0
	Interv year 1993	1.31	0.97 to 1.78	0.07	0.91	0.67 to 1.22	0.5
	Interv year 2002	0.87	0.56 to 1.36	0.6	0.82	0.58 to 1.15	0.3
	Interv year 2006	0.56	0.38 to 0.82	<0.01	0.68	0.48 to 0.96	<0.05
	Interv year 2010	0.47	0.31 to 0.71	<0.001	0.50	0.30 to 0.84	<0.01
Pedestrians	Year	0.93	0.91 to 0.95	<0.001	0.95	0.87 to 1.03	0.2
	Interv year 1993	1.39	0.84 to 2.32	0.3	1.18	0.64 to 2.17	0.6
	Interv year 2002	0.45	0.21 to 0.97	<0.05	0.47	0.21 to 1.02	0.06
	Interv year 2006	0.88	0.39 to 1.95	0.7	1.23	0.47 to 3.20	0.6
	Interv year 2010	1.05	0.54 to 2.03	0.9	1.05	0.44 to 2.51	0.9
Vehicle occupants	Year	0.95	0.94 to 0.97	<0.001	1.01	0.96 to 1.06	0.5
	Interv year 1993	1.32	0.91 to 1.91	0.1	0.85	0.56 to 1.28	0.4
	Interv year 2002	0.87	0.54 to 1.39	0.6	0.79	0.56 to 1.11	0.2
	Interv year 2006	0.51	0.35 to 0.75	<0.01	0.61	0.42 to 0.88	<0.01
	Interv year 2010	0.46	0.31 to 0.69	<0.001	0.49	0.30 to 0.82	<0.01

Unadjusted IRRs relate to univariate analysis of variable for one intervention point and thus equates to the cumulative effect of several interventions after that point. Adjusted IRRs provide estimates for risk relating to effect of one specific intervention point while adjusting for potential confounding effect of other intervention in a multivariable analysis. Total RTC fatalities include additional deaths involving cyclists and other collisions involving motor vehicles, for example, animal riders.
Interv year, year of intervention; IRR, incidence rate ratio; RTC, road transport collision.