The epidemiologic principles underlying traffic safety study designs

Int J Epidemiol. 2016 Oct;45(5):1668-1675. doi: 10.1093/ije/dyw172. Epub 2016 Aug 14.


This article describes the epidemiological principles underlying four observational study designs commonly used to assess traffic safety: the case-control, case-crossover, culpability and quasi-induced exposure designs. We focus in particular on the specific challenges for preventing bias using each design. Whereas recruiting controls representative of the source population poses a special challenge in case-control traffic safety studies, case-crossover designs are prone to recall bias, and culpability and quasi-induced exposure studies can be undermined by difficulties assigning crash responsibility. Using causal diagrams and worked examples, we provide a simple way to teach traffic safety designs to epidemiologists and to encourage proper application of epidemiological principles among researchers designing traffic safety studies.

Publication types

  • Review
  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Accidents, Traffic / prevention & control*
  • Case-Control Studies
  • Cross-Over Studies
  • Data Interpretation, Statistical
  • Humans
  • Observational Studies as Topic
  • Research Design*
  • Safety Management*
  • Social Responsibility