Environmental Determinants of Bicycling Injuries in Alberta, Canada

Table 4

Matched and un-matched logistic regression estimates of the association between environment risk factors and severe bicyclist injury.

	Matched OR	95% CI	Adjustment factors	Un-matched OR	95% CI	Adjustment factors
Traffic volume
Low^a	1	Reference		1	Reference
Med^a	3.20	0.63, 16.25	Riding fast	1.22	0.37, 4.01	Age
High^a	2.01	0.51, 7.94	Riding fast	1.53	0.61, 3.85	Age
Avg. traffic speed (>30 km/hr)	1.7	0, 3.91	^b	4.13	0.89, 19.11	Speed and riding fast
High speed limit (>30 km/hr)	1.85	0.46, 7.47	^b	1.14	0.41, 3.21	^b
Land use
Retail	8.12*	1.66, 39.7	^b	2.53*	1.10, 5.83	Age
School	0.24	0.03, 1.05	^b	0.35	0.04, 2.84	Age and speed
Nature	0.41	0.14, 1.24	Age	1.25	0.60, 2.57	^b
Path characteristics (side 1)
Type of path
Sidewalk	1	Reference		1	Reference
No path	1.29	0.24, 6.81	Riding fast	1.10	0.30, 4.02	^b
Multi-use path^#	0.24*	0.08, 0.77	Riding fast	1.30	0.59, 2.87	^b
Path location (distance from road)
Within 1 m of road	1	Reference		1	Reference
Btw 1 and 3 m of road	0.54	0.14, 2.09	Age	1.68	0.59, 4.81	Speed
>3 m from road	0.48	0.16, 1.45	Age	1.42	0.52, 3.85	Speed
Sloped path	0.42	0, 1.63	^b	1.83	0.71, 4.76	Speed
Path obstructions	0.36	0.13, 1.01	Age	0.81	0.38, 1.74	^b
Path characteristics (side 2)
Type of path
Sidewalk	1	Reference		1	Reference
No path	1.14	0.36, 3.62	Age	0.86	0.28, 2.65	Age and speed
Multi-use path^#	0.40	0.10, 1.68	Age	2.12	0.73, 6.21	Age and speed
Path location (distance from road)
Within 1 m	1	Reference		1	Reference
Btw 1 and 3 m	0.11	0.01, 1.64	Age	0.96	0.28, 3.31	Speed
>3 m	0.36	0.06, 2.06	Age	1.95	0.59, 6.49	Speed
Sloped path	1.11	0.23, 5.32	^b	1.93	0.65, 5.75	^b
Path obstructions	3.32	0.65, 16.9	^b	1.10	0.45, 2.73	^b
Roadway characteristics
Good road condition	0.25*	0.07, 0.96	^b	0.43*	0.19, 0.96	^b
>4 lanes of traffic	2.59	0.80, 8.4	^b	2.31	0.87, 6.16	Age, speed, and riding fast
Curb
Mountable	1	Reference		1	Reference
Non-mountable	4.51*	1.08, 18.8	Sex	1.62	0.71, 3.71	^b
No curb	0.34	0.04, 3.17	Sex	0.44	0.05, 3.53	^b
Crossings	1.1	0.39, 3.15	^b	1.85	0.75, 4.58	Speed
Other routes	0.44	0.16, 1.16	Riding fast	0.75	0.34, 1.68	Speed
Safety characteristics
Street lights (side 1)	1.90	0.70, 5.12	Age	0.78	0.34, 1.79	Speed
Street lights (side 2)	0.89	0.29, 2.77	^b	0.38*	0.15, 0.97	Age and speed
Lighting over path (side 1)	0.36	0.07, 1.86	^b	0.43	0.15, 1.22	Sex
Lighting over path (side 2)	0.58	0.16, 2.15	^b	0.39	0.15, 1.04	Sex
High surveillance	0.53	0.17, 1.71	^b	0.32*	0.13, 0.82	Speed
Aesthetic characteristics
>1 tree/block (side 1)	2.19	0.41, 11.78	^b	2.07	0.57, 7.53	Speed
>1 tree/block (side 2)	1.98	0.22, 17.88	^b	1.75	0.48, 6.42	Speed
Clean	1.79	0.59, 5.43	Age	1.52	0.60, 3.85	^b
Attractive for bicycling	0.4	0.13, 1.23	^b	0.49	0.18, 1.32	Age and speed
Continuity of path	3.0	0.35, 25.96	^b	2.34	0.29, 19.04	Age, speed, and riding fast

MV: motor vehicle; OR: odds ratio; CI: confidence interval.
*Represents significance based on CI not including the null value.
^aLow volume: ≤250 vehicles/hr, medium volume: 250–749 vehicles/hr, high volume: ≥750 vehicles/hr.
^bIf model could not accommodate the addition of one or more covariates, the crude estimate was retained.