Table 1.
Stratified analysis of behavior and environment variables by injury severity score (ISS).
| ISS ≤8 (None or Mild) | ISS >8 (Moderate, Severe or Critical) | |||
|---|---|---|---|---|
|
| ||||
| Variable | n (%) | 95% CI | n (%) | 95% CI |
| Bicycle Route | ||||
|
| ||||
| None | 486 (72%) | 69%–76% | 78 (60%) | 51%–69% |
| Sharrow | 38 (5.6%) | 4.0%–7.7% | 13 (10%) | 5.4%–16% |
| Painted Bicycle Lane | 91 (14%) | 11%–16% | 22 (17%) | 11%–24% |
| Physically Protected Path | 58 (8.4%) | 6.6%–11% | 17 (13%) | 7.8%–20% |
|
| ||||
| Gender | ||||
|
| ||||
| Male | 589 (84%) | 81%–87% | 119 (84%) | 77%–90% |
| Female | 109 (16%) | 13%–19% | 22 (16%) | 10%–23% |
|
| ||||
| Age | ||||
|
| ||||
| <18 | 31 (4.5%) | 3.0%–6.3% | 4 (3.0%) | 0.78%–7.1% |
| 18–55 | 622 (89%) | 87%–91% | 114 (81%) | 73%–87% |
| >55 | 45 (6.5%) | 4.7%–8.5% | 23 (16%) | 11%–23% |
|
| ||||
| Ethnicity | ||||
|
| ||||
| Non-Latino White | 256 (37%) | 33%–41% | 73 (52%) | 43%–60% |
| Black | 92 (13%) | 11%–16% | 8 (5.7%) | 2.5%–11% |
| Latino | 247 (36%) | 32%–39% | 39 (28%) | 20%–36% |
| East Asian | 67 (9.6%) | 7.6%–12% | 16 (11%) | 6.6%–18% |
| South Asian | 15 (2.2%) | 1.2%–3.5% | 3 (2.1%) | 0.44%–6.1% |
| Other | 18 (2.2%) | 1.5%–4.1% | 2 (1.2%) | 0.17%–5.0% |
|
| ||||
| Alcohol Use | ||||
|
| ||||
| No | 663 (95%) | 93%–96% | 119 (84%) | 77%–90% |
| Yes | 35 (5.0%) | 3.5%–6.9% | 22 (16%) | 10%–23% |
|
| ||||
| Bicycle Share | ||||
|
| ||||
| No | 346 (95%) | 92%–97% | 83 (97%) | 90%–99% |
| Yes | 19 (5.0%) | 3.2%–8.0% | 3 (3.0%) | 0.73%–9.9% |
|
| ||||
| Wore Helmet | ||||
|
| ||||
| No | 454 (66%) | 62%–70% | 96 (70%) | 62%–76% |
| Yes | 234 (34%) | 30%–38% | 41 (30%) | 22%–38% |
|
| ||||
| Delivery Worker | ||||
|
| ||||
| No | 421 (62%) | 58%–65% | 114 (84%) | 77%–90% |
| Yes | 263 (38%) | 35%–42% | 21 (16%) | 10%–23% |
|
| ||||
| Self Reported Speed | ||||
|
| ||||
| <5 mph | 66 (21%) | 16%–25% | 18 (28%) | 17%–40% |
| 5–15 mph | 230 (72%) | 67%–77% | 39 (60%) | 47%–72% |
| >15 mph | 24 (7.0%) | 5.0%–11% | 8 (12%) | 5.5%–23% |
|
| ||||
| Hit by Turning Vehicle | ||||
|
| ||||
| No | 230 (40%) | 36%–45% | 51 (55%) | 44%–65% |
| Yes | 339 (60%) | 55%–64% | 42 (45%) | 35%–56% |
|
| ||||
| Distracted Riding (cell phones, audio equipment, etc.) | ||||
|
| ||||
| No | 616 (90%) | 88%–92% | 116 (91%) | 84%–95% |
| Yes | 68 (10%) | 8.0%–12% | 12 (9%) | 5.0%–16% |
|
| ||||
| Salmoning (riding against traffic) | ||||
|
| ||||
| No | 590 (92%) | 90%–94% | 102 (89%) | 81%–94% |
| Yes | 51 (8.0%) | 6.0%–10% | 13 (11%) | 6.0%–18% |
|
| ||||
| Motor Vehicle Type | ||||
|
| ||||
| Passenger Car | 258 (42%) | 38%–46% | 54 (49%) | 39%–58% |
| Taxi | 261 (42%) | 38%–46% | 26 (23%) | 16%–32% |
| SUV, Van, or Truck | 98 (16%) | 13%–19% | 31 (28%) | 20%–37% |
|
| ||||
| Road Condition | ||||
|
| ||||
| Normal | 610 (89%) | 86%–91% | 122 (90%) | 84%–95% |
| Wet or Iced | 75 (11%) | 8.7%–14% | 13 (10%) | 5.2%–16% |
|
| ||||
| At Stop Sign | ||||
|
| ||||
| No | 652 (98) | 96%–99% | 117 (94%) | 89%–98% |
| Yes | 15 (2.0%) | 1.3%–3.7% | 7 (6.0%) | 2.3%–11% |
|
| ||||
| At Traffic Signal | ||||
|
| ||||
| No | 320 (50%) | 46%–54% | 44 (38%) | 29%–47% |
| Yes | 322 (50%) | 46%–54% | 73 (62%) | 53%–71% |
|
| ||||
| Daylight Condition | ||||
|
| ||||
| Daylight | 221 (68%) | 62%–73% | 26 (50%) | 36%–64% |
| Night | 106 (32%) | 28%–38% | 26 (50%) | 36%–64% |
|
| ||||
| A.M. Rush Hour | ||||
|
| ||||
| No | 639 (93%) | 91%–95% | 127 (91%) | 85%–95% |
| Yes | 50 (7.0%) | 5.0%–10% | 12 (8.0%) | 5.0%–15% |
|
| ||||
| P.M. Rush Hour | ||||
|
| ||||
| No | 592 (86%) | 83%–89% | 122 (88%) | 81%–93% |
| Yes | 96 (14%) | 11%–17% | 17 (12%) | 7.3%–19% |
|
| ||||
| Road Classification | ||||
|
| ||||
| Local Street | 326 (75%) | 70%–79% | 58 (67%) | 56%–76% |
| Avenue or Two Way Arterial | 110 (25%) | 21%–30% | 29 (33%) | 24%–44% |