Site/severity | 2 years pre-implementation | 1 year pre-implementation | Intervention implementation | 1 year post-implementation | 3 years post-implementation |
2014 | 2015 | 2016 | 2017 | 2019 | |
Intervention site | |||||
Slight injury | 80 (−7%; p=0.64) | 86 (Ref) | 76 (−12%; p=0.43) | 76 (−12%; p=0.43) | 72 (−16%; p=0.27) |
Serious injury/fatal | 4 (+100%; p=0.42) | 2 (Ref) | 3 (+50%; p=0.66) | 9 (+350%; p=0.05) | 3 (+50%; p=0.66) |
Overall | 84 (−5%; p=0.76) | 88 (Ref) | 79 (−10%; p=0.47) | 85 (−3%; p=0.82) | 75 (−15%; p=0.31) |
Control site (city centre) | |||||
Slight injury | 100 (+2%; p=0.89) | 98 (Ref) | 101 (+3%; p=0.83) | 90 (−8%; p=0.56) | 106 (+8%; p=0.58) |
Serious injury/fatal | 6 (+50%; p=0.53) | 4 (Ref) | 7 (+75%; p=0.37) | 12 (+200%; p=0.06) | 8 (+100%; p=0.26) |
Overall | 106 (+4%; p=0.78) | 102 (Ref) | 108 (+6%; p=0.68) | 102 (0%; p=1.00) | 114 (+12%; p=0.41) |
Control site (metropolitan area) | |||||
Slight injury | 1078 (+6%; p=0.19) | 1018 (Ref) | 1034 (+2%; p=0.72) | 974 (−4%; p=0.32) | 939 (−8%; p=0.07) |
Serious injury/fatal | 79 (−11%; p=0.44) | 89 (Ref) | 102 (+15%; p=0.35) | 97 (+9%; p=0.56) | 67 (−25%; p=0.08) |
Overall | 1157 (+5%; p=0.29) | 1107 (Ref) | 1136 (+3%; p=0.54) | 1071 (−3%; p=0.44) | 1006 (−9%; p=0.03) |
Matched control | |||||
Slight injury | 26 (0%; p=1.00) | 26 (Ref) | 23 (−12%; p=0.67) | 25 (−4%; p=0.89) | 23 (−12%; p=0.67) |
Serious injury/fatal | 2 (+100%; p=0.57) | 1 (Ref) | 1 (0%; p=1.00) | 3 (+200%; p=0.34) | 1 (0%; p=1.00) |
Overall | 28 (+4%; p=0.89) | 27 (Ref) | 24 (−11%; p=0.68) | 28 (+4%; p=0.89) | 24 (−11%; p=0.68) |
Fatal injury is one which causes death less than 30 days after the accident. Serious injury is one which does not cause death but serious injury such as needing to be detained in hospital as an inpatient, fractures, concussion, internal injuries. Slight injury is any injury which is neither ‘fatal’ nor ‘serious’, for example, a sprain, bruise or cut which is not judged to be severe, or slight shock requiring roadside attention.
Ref, reference case.