Intended for healthcare professionals


Role of mobile phones in motor vehicle crashes resulting in hospital attendance: a case-crossover study

BMJ 2005; 331 doi: (Published 18 August 2005) Cite this as: BMJ 2005;331:428
  1. Suzanne P McEvoy, senior research fellow (smcevoy{at},
  2. Mark R Stevenson, professor of injury prevention1,
  3. Anne T McCartt, vice president, research2,
  4. Mark Woodward, professor of biostatistics1,
  5. Claire Haworth, research nurse3,
  6. Peter Palamara, senior research officer3,
  7. Rina Cercarelli, senior research fellow3
  1. 1 The George Institute for International Health, University of Sydney, PO Box M201, Sydney, NSW 2050, Australia
  2. 2 Insurance Institute for Highway Safety, Arlington, VA, USA
  3. 3 Injury Research Centre, University of Western Australia, Crawley, WA 6009, Australia
  1. Correspondence to: S McEvoy
  • Accepted 24 June 2005


Objectives To explore the effect of drivers' use of mobile (cell) phones on road safety.

Design A case-crossover study.

Setting Perth, Western Australia.

Participants 456 drivers aged ≥ 17 years who owned or used mobile phones and had been involved in road crashes necessitating hospital attendance between April 2002 and July 2004.

Main outcome measure Driver's use of mobile phone at estimated time of crash and on trips at the same time of day in the week before the crash. Interviews with drivers in hospital and phone company's records of phone use.

Results Driver's use of a mobile phone up to 10 minutes before a crash was associated with a fourfold increased likelihood of crashing (odds ratio 4.1, 95% confidence interval 2.2 to 7.7, P < 0.001). Risk was raised irrespective of whether or not a hands-free device was used (hands-free: 3.8, 1.8 to 8.0, P < 0.001; hand held: 4.9, 1.6 to 15.5, P = 0.003). Increased risk was similar in men and women and in drivers aged ≥ 30 and < 30 years. A third (n = 21) of calls before crashes and on trips during the previous week were reportedly on hand held phones.

Conclusions When drivers use a mobile phone there is an increased likelihood of a crash resulting in injury. Using a hands-free phone is not any safer.


  • Contributors SPM and MRS contributed to study design, conduct, analysis, and writing of the manuscript. ATM contributed to study design, analysis, and writing of the manuscript. MW contributed to study analysis and writing of the manuscript. CH, PP, and RC contributed to study design and conduct. MRS is guarantor.

  • Funding Insurance Institute for Highway Safety. SPM received a National Health and Medical Research Council postgraduate public health scholarship.

  • Competing interests None declared.

  • Ethical approval Human research ethics committees at the University of Western Australia and the participating hospitals approved the study.

  • Accepted 24 June 2005
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