A scoping review on the methods used to assess health-related quality of life and disability burden in evaluations of road safety interventions

Introduction: Road traffic crashes globally cause 1.3 million deaths yearly and the rate of nonfatal crashes is increasing. Nonfatal injuries impact long-term quality of life, which is often overlooked in evaluations. The preferred method for using health-related quality of life and disability for evaluating road safety interventions have not been established. Method: A scoping review of peer-reviewed and grey literature was undertaken to understand health-related quality of life and disability measures currently used to evaluate road safety interventions. We included English language studies that used any health-related quality of life or disability measure to evaluate any real-world intervention aimed at reducing the number or severity of road traffic crashes. Results: Nine different health-related quality of life measures were used in the 18 included studies. The most commonly used measure was a quality-adjusted life year, which was used by seven studies, followed by the Glasgow Outcome Scale used by five studies. Two studies used two different health-related quality of life or disability measures. Five studies used primary data (collected directly for the purpose of the study) and 13 studies used existing data sources not explicitly collected for the reported evaluation. Of these 13 studies, 5 used an injury registry as the data source. Six different methods of deriving utility weights for calculating qualityadjusted life years were used. Conclusions: This review found that evaluations of road safety interventions using health-related quality of life or disability measures were rare. There was a lack of consistency in the measures used which prevented comparisons across evaluations. Further, inconsistent methods were used to derive utility weights for quality-adjusted life years. Practical Applications: Future evaluations of roads safety interventions need to consider longer-term outcomes. Consistent methods for measuring health-related quality of life and disability burden are needed, as are empirically derived utility weights for quality-adjusted life years.