Impact of the bicycle helmet wearing programme on head injuries among 5 to 12 year old children, comparing the implementation and post-implementation periods with the pre-implementation period, and considering different categories of municipalities within the experimental and comparison groups
| Target community | Comparison community | |||||||
|---|---|---|---|---|---|---|---|---|
| Poor municipalities | Average rich municipalities | Poor municipalities | Average rich municipalities | |||||
| Incidence rate/1000 | Rates ratios (95% CI) | Incidence rate/1000 | Rates ratios (95% CI) | Incidence rate/1000 | Rates ratios (95% CI) | Incidence rate/1000 | Rates ratios (95% CI) | |
| A: Head injuries | ||||||||
| Pre-implementation 1988–1990 | 1.53 | 1.00 | 1.04 | 1.00 | 0.48 | 1.00 | 0.70 | 1.00 |
| Implementation 1991–1993 | 1.06 | 0.69 (0.43 to 1.11) | 0.83 | 0.79 (0.60 to 1.04) | 1.06 | 2.20 (0.77 to 6.34) | 0.70 | 1.00 (0.68 to 1.47) |
| Post-implementation 1994–1996 | 0.69 | 0.45 (0.26 to 0.78) | 0.58 | 0.55 (0.41 to 0.75) | 0.64 | 1.40 (0.44 to 4.41) | 0.68 | 0.98 (0.65 to 1.45) |
| B: Others injuries | ||||||||
| Pre-implementation 1988–1990 | 1.49 | 1.00 | 1.02 | 1.00 | 1.63 | 1.00 | 1.14 | 1.00 |
| Implementation 1991–1993 | 1.68 | 1.12 (0.74 to 1.71) | 1.10 | 1.07 (0.83 to 1.38) | 1.73 | 1.06 (0.54 to 2.06) | 1.05 | 0.93 (0.68 to 1.27) |
| Post-implementation 1994–1996 | 1.42 | 0.95 (0.61 to 1.47) | 1.06 | 1.04 (0.80 to 1.34) | 1.35 | 0.82 (0.41 to 1.67) | 1.01 | 0.89 (0.65 to 1.22) |
| Study population | 27450 | 111370 | 10400 | 73129 | ||||