Change in crash rates associated with five-unit increase in compliance score from the overall and refined model
| Composite lighting and marking score* | Lighting score | Marking score | ||||
|---|---|---|---|---|---|---|
| Rate ratio (95% CI) | p Value | Rate ratio (95% CI) | p Value | Rate ratio (95% CI) | p Value | |
| Crude model† | 0.89 (0.81 to 0.99) | 0.0263 | 0.86 (0.76 to 0.97) | 0.0146 | 0.92 (0.87 to 0.97) | 0.0010 |
| Adjusted model‡ | 0.83 (0.78 to 0.88) | <0.0001 | 0.48 (0.45 to 0.51) | <0.0001 | 0.89 (0.83 to 0.96) | 0.0018 |
*Data aggregated over 5 years for analysis.
†Model includes each score and two indicators for IL and MO.
‡Model includes each score, five confounders (population, tightness, per cent GDP, net cash income, average farm size) and two indicators for IL and MO.
IL, Illinois; GDP, gross domestic product; MO, Missouri.