Prevalence of Alcohol Impairment and Odds of a Driver Injury or Fatality in On-Road Farm Equipment Crashes

<p><b>Objective</b>. To estimate the prevalence of alcohol impairment in crashes involving farm equipment on public roadways and the effect of alcohol impairment on the odds of crash injury or fatality.</p> <p><b>Methods</b>. On-road farm equipment crashes were collected from four Great Plains state Departments of Transportation during 2005–2010. Alcohol impairment was defined as an involved driver having blood alcohol content of ≥0.08 g/100 ml or a finding of alcohol-impaired as a driver contributing circumstance recorded on the police crash report. Injury or fatality was categorized as: a) no injury (no and possible injury combined), b) injury (non-incapacitating or incapacitating injury,) and c) fatality. Hierarchical multivariable logistic regression modeling, clustered on crash, was used to estimate the odds of an injury/fatality in crashes involving an alcohol-impaired driver.</p> <p><b>Results</b>. During the five years under study, 3.1% (61 of 1971) of on-road farm equipment crashes involved an alcohol-impaired driver. One in twenty (5.6%) injury crashes and one in six (17.8%) fatality crashes involved an alcohol-impaired driver. The non-farm equipment driver was significantly more likely to be alcohol-impaired than the farm equipment driver (2.4% versus 1.1% respectively, p = 0.0012). After controlling for covariates, crashes involving an alcohol-impaired driver had 4.10 (95% CI: 2.30-7.28) times the odds of an injury or fatality. In addition, the non-farm vehicle driver was at 2.28 (95% CI: 1.92-2.71) times higher odds of an injury or fatality than the farm vehicle driver. No differences in rurality of the crash site were found in the multivariable model.</p> <p><b>Conclusion</b>. On-road farm equipment crashes involving alcohol result in greater odds of an injury or fatality. The risk of injury or fatality is higher among the non-farm equipment vehicle drivers who are also more likely to be alcohol-impaired. Further studies are needed to measure the impact of alcohol impairment in on-road farm equipment crashes.</p>