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Bicycle helmets do protect against head injuries

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00.01hrs BST
Friday 27 October 2000

The number of serious head injuries among cyclists of all ages has fallen as a result of increasing helmet use, despite doubts about the effectiveness of helmets, report researchers from Imperial College in this week's BMJ (1).

Dr Aziz Sheikh and Adrian Cook of the Department of Primary Health Care and General Practice, Imperial College School of Medicine, analysed all cyclist hospital admissions in England between April 1991 and March 1995, a period of increasing helmet usage.

They divided patients into three age categories: junior (6-10 years), secondary (11-15 years), and adult (16 years and over).

The authors found that numbers of emergency admissions among cyclists changed little over the four-year study period, from a total of 8,678 in 1991-92 to 8,781 in 1994-95.

However the percentage admitted with head injuries fell significantly from 40% to 28% per month, and each age group showed a significant reduction: 9% among junior, 11% among secondary and 13% among adults.

These findings indicate that helmets are of benefit both to children and, contrary to popular belief, to adults, say the authors.

While previous reports have suggested that helmets confer benefit, doubts have been expressed about the accuracy of these findings because of the difficulties in adjusting for differences in risk-taking behaviours between helmet wearers and non-wearers.

Dr Sheikh points out that helmets are not designed to protect the rider in a fall which involves other vehicles. Most adult accidents involve other vehicles.

"The reasoning behind this is that when a cyclist is knocked off by another vehicle, this frequently results in the head being spun and subjected to torsional effects. One consequence of this is that they tend not to hit the ground as cleanly as children who are typically involved in low-impact, non-twisting injuries," said Dr Sheikh.

Dr Sheikh described the results from their study as among the strongest yet presented. "We've seen that cyclist head injuries fell sharply during a period of increased helmet wearing."

"Stronger evidence may never emerge, given the practical problems of comparing helmet wearers with non-wearers, and the ethical problems of conducting a randomised trial," he added.

Writing in the BMJ the authors conclude, "Local publicity campaigns encouraging the voluntary wearing of helmets have been effective and should accompany national drives to promote cycling."

But Dr Sheikh also revealed that while head injuries fell during the study period, other cycling injuries (limb and miscellaneous) increased.

"Cycle helmets are therefore only a partial solution to improving safety in this group of road-users," he said.


For further information please contact:

Adrian Cook
Department of Primary Health Care and General Practice
Imperial College School of Medicine
Tel: +44 (0)20 7594 3350
Fax: +44 (0)20 7706 8426

Dr Aziz Sheikh
Department of Primary Health Care and General Practice
Imperial College School of Medicine
Tel: +44 (0)20 7594 3384
Fax: +44 (0)20 7706 8426

Tom Miller
Imperial College Press Office
Tel: +44 (0)20 7594 6704
Fax: +44 (0)20 7594 6704

Notes to editors:

1. Details of the paper:

Title: Trends in serious head injuries among cyclists in England: analysis of routinely in England: analysis of routinely collected data

Journal: BMJ Volume 321, No. 7268 - 28 October 2000.
Website at:

Authors: Adrian Cook, Aziz Sheikh

Department of Primary Health Care and General Practice, Imperial College School of Medicine, Norfolk Place, London, W2 1PG, UK

2. Dr Aziz Sheikh is NHS R&D National Primary Care Training Fellow in the Department of Primary Health Care and General Practice at Imperial College School of Medicine. He is based on the St Mary's campus in Paddington. Dr Sheikh published a widely-praised book, Caring for Muslim Patients giving advice on caring for Muslim patients in April 2000. Dr Sheikh is a GP and he practises in Harrow, north-west London.

3. Mr Adrian Cook is a statistician in the Department of Primary Health Care and General Practice at Imperial College School of Medicine, based on the St Mary's campus in Paddington. He works on the analysis of large, routinely collected datasets. He is currently working on a mortality comparison of the major UK trusts, and recently co-authored a report on paediatric cardiac mortality for the Bristol Royal Infirmary public inquiry.

4. The Division of Primary Care and Population Health Sciences is a world-class centre for research and teaching in primary health care, epidemiology, public health, biostatistics, community genetics, health services and social sciences.

The Department of Primary Health Care and General Practice is one of the largest departments in this Division. Current research includes disease intervention studies in primary care, allergy control, primary care epidemiology and surveillance, and service delivery. The department has an active Medical Ethics Unit and launched its new MSc in Medical Ethics in October 2000. The department also carries out large amounts of teaching on the undergraduate medicine course, and hosts the West London Research Network (WeLReN) in co-operation with various local primary care institutions.

The Department will shortly be joining the Department of Social Science and Medicine at the Charing Cross Hospital campus to form the new Centre for Primary Care and Social Medicine. Website at:

5. Imperial College of Science, Technology and Medicine is an independent constituent part of the University of London. Founded in 1907, the College teaches a full range of science, engineering, medical and management disciplines at the highest level. The College is the largest applied science and technology university institution in the UK, with one of the largest annual turnovers (UKP330 million in 1998-99) and research incomes (UKP173 million in 1998-99). Web site at