Table 3.
County-level regression analysis
| Unadjusted | Adjusted* | |||||
|---|---|---|---|---|---|---|
| Coefficie | 95% CI | p Value | Coefficient | 95% CI | p Value | |
| Injury prevention policies | ||||||
| Primary seat belt enforcement | −9.2 | −18.4 to 0.0 | 0.050 | −10.9 | −18.6 to −3.1 | 0.006 |
| Ignition interlock requirement for drunk driving | 1.5 | −8.5 to 11.5 | 0.769 | 3.9 | −5.5 to 13.3 | 0.412 |
| Motorcycle helmet requirement | −7.7 | −16.2 to 0.9 | 0.078 | −7.0 | −14.0 to 0.1 | 0.052 |
| Booster seat requirement for children under age 8 | −12.8 | −21.1 to −4.4 | 0.003 | −9.4 | −17.4 to −1.3 | 0.022 |
| Bicycle helmet requirement for children | −11.7 | −20.1 to −3.3 | 0.007 | −8.5 | −15.3 to −1.8 | 0.013 |
| Access to orders of protection for IPV in dating | −6.0 | −19.7 to 7.8 | 0.395 | −2.8 | −17.5 to 11.9 | 0.709 |
| Access to orders of protection for teen dating | −2.6 | −14.7 to 9.5 | 0.669 | −0.5 | −11.5 to 10.5 | 0.934 |
| Strict youth sports concussion laws | −4.8 | −15.5 to 6.0 | 0.384 | −0.6 | −9.4 to 10.6 | 0.907 |
| Prescription drug monitoring programme | 5.7 | −2.8 to 14.3 | 0.189 | 6.2 | 1.4 to 10.9 | 0.011 |
| External cause-of-injury coding | −8.0 | −16.5 to 0.5 | 0.066 | −5.8 | −12.9 to 1.4 | 0.113 |
| Strict gun regulations | −23.9 | −31.3 to 16.4 | <0.001 | −12.6 | −19.2 to −6.0 | <0.001 |
| Weak | 0 | ref | 0 | ref | ||
| Moderate | −1.2 | 11.1 to 8.8 | 0.819 | −0.5 | −12.0 to 11.1 | 0.936 |
| Strong | −19.3 | −27.6 to −11.0 | <0.001 | −11.8 | −18.6 to −5.0 | 0.001 |
| County characteristics | ||||||
| Median household income (z score) | −12.9 | −15.0 to −10.9 | <0.001 | −5.9 | −8.4 to −3.5 | <0.001 |
| Rural county | 22.3 | 18.6 to 26.0 | <0.001 | 5.6 | 2.2 to 9.1 | 0.001 |
| White population (%) | 0.1 | −0.1 to 0.3 | 0.248 | 0.1 | 0.0 to 0.2 | 0.184 |
| Population with some college education (%) | −1.0 | −1.2 to −0.8 | <0.001 | −0.2 | −0.4 to 0.0 | 0.038 |
| Uninsured population (%) | 1.4 | 0.5 to 2.4 | 0.003 | −0.1 | −0.6 to 0.4 | 0.709 |
| Unemployed population (%) | 1.9 | 0.5 to 3.2 | 0.008 | 1.1 | 0.0 to 2.2 | 0.045 |
| Population <18 years (%) | −0.5 | −1.6 to 0.6 | 0.359 | 1.1 | 0.3 to 2.0 | 0.010 |
| Population ≥65 years (%) | 2.7 | 2.0 to 3.4 | <0.001 | 2.4 | 1.7 to 3.1 | <0.001 |
| Per cent of MVCs involving alcohol | 0.2 | 0.0 to 0.4 | 0.041 | 0.2 | 0.1 to 0.3 | 0.003 |
*
Policy coefficients are adjusted for county characteristics. Adjusted coefficients for each county characteristic are drawn from the model using policy tertiles.
IPV, intimate partner violence.