Stratified ORs estimating the association of Bike Ed with injury risk within subgroups of the population
| OR | 95% CI | p Value* | OR (boys) | OR (girls) | |
|---|---|---|---|---|---|
| *χ2 Test for homogeneity of the OR across strata. | |||||
| †Control groups for these subgroup analyses overlap, so a standard test of homogeneity between the ORs is not possible. | |||||
| Sex | 0.32 | ||||
| Boys | 2.0 | (1.1 to 3.8) | — | — | |
| Girls | 1.1 | (0.43 to 3.0) | — | — | |
| Age (years) | 0.41 | ||||
| 9–11 | 2.1 | (0.97 to 4.4) | 2.3 | 1.8 | |
| 12–14 | 1.3 | (0.66 to 2.70) | 1.9 | 0.43 | |
| Maternal education | 0.39 | ||||
| Primary | 1.9 | (0.64 to 5.7) | 3.0 | 1.2 | |
| Secondary | 1.9 | (0.94 to 3.7) | 2.1 | 1.4 | |
| Tertiary | 0.63 | (0.16 to 2.6) | 1.1 | — | |
| Other family members bicycle | 0.04 | ||||
| Yes | 1.1 | (0.56 to 2.0) | 1.2 | 1.0 | |
| No | 3.4 | (1.4 to 8.3) | 5.0 | 1.3 | |
| Parents restrict range | 0.17 | ||||
| Yes | 1.4 | (0.78 to 2.4) | 1.7 | 0.90 | |
| No | 4.0 | (1.0 to 15.3) | 4.8 | 2.3 | |
| Exposure (km) | 0.59 | ||||
| Play only | 1.4 | (0.42 to 4.8) | 1.1 | 2.3 | |
| 0–4 | 2.9 | (1.0 to 8.6) | 4.2 | — | |
| 5–12 | 1.6 | (0.59 to 4.1) | 1.9 | 0.86 | |
| > 12 | 1.1 | (0.40 to 2.8) | 1.5 | — | |
| Activity | † | ||||
| Play | 2.0 | (0.98 to 4.3) | 2.4 | 1.9 | |
| Travel | 1.5 | (0.82 to 2.9) | 2.0 | 0.4 | |
| Location | † | ||||
| Road | 1.2 | (0.58 to 2.4) | 1.4 | 0.8 | |
| Sidewalk | 1.8 | (0.84 to 3.9) | 2.1 | 1.2 | |
| Other | 2.3 | (0.87 to 5.9) | 2.6 | 2.3 | |