Distribution of individual and community level characteristics in the total study population and by community social capital (SC) status
| Total | High SC (n=143) | Medium SC (n=140) | Low SC (n=136) | p Value* | |
|---|---|---|---|---|---|
| Individual level characteristics | |||||
| Number of student | 23 532 | 7799 | 8389 | 7344 | |
| Age (mean, SD) | 14.2 (1.5) | 13.9 (1.5) | 14.2 (1.5) | 14.3 (1.5) | <0.0001 |
| Per cent male | 48.17 | 49.3 | 47.6 | 47.7 | 0.06 |
| Number of injured (%) | 3449 (14.7) | 1142 (14.6) | 1221 (14.6) | 1086 (14.8) | 0.92 |
| Family affluence (%) | <0.0001 | ||||
| Well off | 12 598(53.6) | 3891 (49.9) | 4544 (54.2) | 4163 (56.7) | |
| Average | 7978 (33.9) | 2871 (36.8) | 2828 (33.7) | 2279 (31) | |
| Not well off | 2223 (9.4) | 827 (10.6) | 778 (9.3) | 613 (8.4) | |
| Missing | 733 (3.1) | 210 (2.7) | 239 (2.8) | 284 (3.9) | |
| Community level characteristics† | |||||
| Socioeconomic status indicators | |||||
| Average income $ (mean, SD) | 76 015 (23 768) | 78 115(29 820) | 76 553 (18 625) | 73 215 (21 063) | 0.21 |
| Employed (mean proportion, SD) | 0.62 (0.11) | 0.61 (0.11) | 0.63 (0.11) | 0.63 (0.11) | 0.19 |
| High school diploma and higher (mean proportion, SD) | 0.72 (0.13) | 0.73 (0.13) | 0.73 (0.12) | 0.69 (0.14) | 0.02 |
| SES composite index | 6 (2.1) | 6.2 (2.1) | 6.4 (2.1) | 5.7 (1.9) | 0.04‡ |
| Built environment characteristics | |||||
| Intersection density (mean, SD) | 40.6 (29.2) | 40.6 (37.9) | 38.4 (19.8) | 42.9 (26.5) | 0.43 |
| Average block length (mean, SD) | 283 (230) | 308 (329) | 278 (187) | 262 (113) | 0.23 |
| Connected nodes ratio (mean, SD) | 0.83 (0.10) | 0.82 (0.10) | 0.82 (0.11) | 0.85 (0.09) | 0.05 |
| Street connectivity composite index (mean, SD) | 6.0 (2.0) | 5.9 (1.9) | 5.8 (2.0) | 6.3 (2.0) | 0.07 |
| Green space (mean, SD) | 0.14 (0.14) | 0.138 (0.14) | 0.14 (0.14) | 0.139 (0.13) | 0.99 |
| Population health status | |||||
| Average rates of injuries | 0.14 (0.06) | 0.14 (0.07) | 0.14 (0.06) | 0.13 (0.06) | 0.39 |
*Comparing social capital groups by analysis of variance and χ2 test when appropriate.
†At 1 km buffer of schools.
‡Low SC group significantly different from medium SC group (Boneferroni multiple comparison test).