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Cochrane Review: Helmets for preventing head and facial injuries in bicyclists

Thompson RS, Rivara FP & Thompson DC. Cochrane Database of Systematic Reviews, The Cochrane Library.

Full source document
(Note: Access to the Cochrane database may be denied from some countries)

Authors' abstract  

This page gives information about this paper and summarises the key criticisms.

For a more detailed critique please see here


The Cochrane database has established a reputation as a key resource for medical research. This particular review, however, has attracted considerable criticism. Some of this criticism is included with the reviewers' paper on the Cochrane database and thus forms an integral part of the review. However, submissions were sometimes shortened and summarised in a way that omits key concerns. See here for the full version of one detailed critique (BHRF, 1243).

Published peer criticism

Elvik, 2011 has criticised the criteria  used for the inclusion of studies in this review, noting that most of the included studies were the work of the reviewers themselves. Citing criteria estalished by Littell, Corcoran and Pillai, 2008, Elvik suggests that the authors had a conflict of interest in carrying out the review which they have not declared. In considering the assessment of quality of the same papers used by Towner et al, 2002, Elvik, 2011 finds that it is not at all clear that the omitted studies were of lower quality than the studies included. A more transparent process would have included all the papers together with the publication of quality scores and a sensitivity analysis.

As part of his re-analysis of Attewell, Glase and McFadden, 2001, Elvik, 2011 considered the same studies used in the Cochrane Review and also more recently published studies. Later studies show no net benefit from helmets with regard to injuries to the head, face and neck.

Curnow, 2005 examines the Cochrane Review in detail. He concludes that the review takes no account of scientific knowledge of the types and mechanisms of brain injury. It provides, at best, evidence that hard-shell helmets, now rarely used, protect the brain from injury consequent upon damage to the skull. The review therefore is not a reliable guide to the efficacy of helmets and to interventions concerning their use.

Studies on which the review is based

Injury patterns in cyclists attending an accident and emergency department: a comparison of helmet wearers and non-wearers.
Maimaris C, Summers CL, Browning C, Palmer CR. BMJ, 1994;308(6943):1537-1540.
See: Commentary

The effectiveness of bicyclist helmets: a study of 1701 casualties.
McDermott FT, Lane JC, Brazenore GA, Debney EA. Journal of Trauma, 1993;34(6):834-845.
See: Commentary

Effectiveness of bicycle helmets in preventing head injury in children.
Thomas S, Acton C, Nixon J, Battistutta D, Pitt WR, Clark R. BMJ, 1994;308:173-176.
See: Brief Notes

Effectiveness of bicycle safety helmets in preventing head injuries: a case-control study.
Thompson DC, Rivara FP, Thompson RS. JAMA, 1996;276(24):1968-1973.
See: Commentary

A case-control study on the effectiveness of bicycle safety helmets.
Thompson RS, Rivara FP, Thompson DC. New England Journal of Medicine, 1989;320:1361-1367.
See: Commentary

A case-control study on the effectiveness of bicycle safety helmets in preventing facial injury.
Thompson DC, Thompson RS, Rivara FP, Wolf ME. American Journal of Public Health, 1990;80(12):1471-1474.

Effectiveness of bicycle safety helmets in preventing serious facial injury.
Thompson DC, Nunn ME, Thompson RS, Rivara FP. JAMA 1996a;276(24):1974-1975.

Summary of criticisms

Principal criticisms of the review are:


Attewell, Glase and McFadden, 2001

Attewell RG, Glase K, McFadden M, 2001. Bicycle helmet efficacy: a meta-analysis. Accident Analysis & Prevention 2001-05 v33 n3 p345-52.

BHRF, 1039

Cycle helmets and rotational injuries. .

BHRF, 1052

Contradictory evidence about the effectiveness of cycle helmets. .

BHRF, 1068

A case study of the effectiveness of bicycle helmets. .

BHRF, 1096

Helmet laws: what has been their effect?. .

BHRF, 1243

Helmets for preventing head and facial injuries in bicycles - critique. .

Curnow, 2005

Curnow WJ, 2005. The Cochrane Collaboration and bicycle helmets. Accident Analysis & Prevention 2005;37(3):569-573.

Elvik, 2011

Elvik R, 2011. Publication bias and time-trend bias in meta-analysis of bicycle helmet efficacy: A re-analysis of Attewell, Glase and McFadden, 2001. Accident Analysis & Prevention 2011;43(3):1245-1251.

Gregory, Inwood and Sexton, 2003

Gregory K, Inwood C, Sexton B, 2003. Cycle helmet wearing in 2002. Transport Research Laboratory Report 578.

Littell, Corcoran and Pillai, 2008

Littell JH, Corcoran J, Pillai V, 2008. Systematic reviews and meta-analysis. Oxford University Press ISBN13: 9780195326543.

Mok et al, 2004

Mok D, Gore G, Hagel B, Mok E, Magdalinos H, Pless IB, 2004. Risk compensation in children's activities: A pilot study. Paediatr Child Health 2004;9(5):327-330.

Towner et al, 2002

Towner E, Dowswell T, Burkes M, Dickinson H, Towner J, Hayes M, 2002. Bicycle helmets - a review of their effectiveness: a critical review of the literature. Department for Transport Road Safety Research Report 30.

See also