Structured Abstract
Brain Injury Stuctured Abstract - BI #9
Helmets are effective in preventing head injuries in bicycles riders
CITATION: Thompson, R. S., Rivara, F. P., & Thompson, D. C. (1989). A case-control study of the effectiveness of bicycle safety helmets. The New England Journal of Medicine, 320(21), 1361-1367.
LEVEL OF EVIDENCE: IIA2a
This case control design study, sample size ranged 1,226 (n = 235, n = 433, n = 558), with moderate -low internal validity and high external validity provided a high level of evidence IIA.
RESEARCH OBJECTIVE/QUESTION
To assess the effectiveness of bicycle helmets in reducing the risk of head injury in accidents.
DESIGN
| |
RCT |
|
Single Case |
X |
Case Control |
| |
Cohort |
|
Before-After |
|
Cross-Sectional |
This study is also known as a retrospective study or a case comparison study. A case control study is generally performed to view in retrospect to see how a certain issue affected a group of clients involved in the study. Therefore, one can find out what makes these clients different from each other. The group of clients exposed to the issue in question is compared to a similar control group that was not exposed to the issue. Case patients were persons with head injuries received while bicycling and the control group consisted of persons who received care for bicycling injuries not affecting the head.
SAMPLING PROCEDURE
|
X |
Random |
|
Consecutive |
| |
Controlled |
|
Convenience |
Individuals involved in the study are selected at random from a larger population of candidates
The persons for the study were treated in the give hospital emergency rooms for bicycling injuries.
SAMPLE
|
N = 1,223 |
M age =
≤ 14 - ≥ 25 |
Male =
912
Female = 314 |
Ethnicity = NR |
Female = 314 |
NR = Not reported
|
Participants |
|
Males = 171 case clients
Females = 64 case clients |
304 emergency room
129 emergency room
433 control group not involving head |
437 population control = 912
121 population control = 314
558 bicycle accidents previous year |
PARTICIPANT CHARACTERISTICS
Bicyclists who sought care for bicycle-related head injury
MEDICAL DIAGNOSIS/CLINICAL DISORDER
Traumatic brain injury
OT TREATMENT DIAGNOSIS
Environmental (sociocultural) problems
OUTCOMES
Brain Injury Prevention
|
Measures |
Reliability |
Validity |
|
1. Questionnaire |
NR |
NR |
|
2. Abbreviated Injury Scale |
NR |
NR |
NR = Not Reported
Outcome - OT terminology
Prevention
III. Performance context
B. Environmental Aspects:
2. Social
3. Cultural
Outcome - ICIDH-2 terminology
Participation: Environmental and cultural aspects - prevention
INTERVENTION
Helmets used for cyclists vs. Non-helmet use
Description
Survey of two control groups to assess safety of helmets for cyclists
- Emergency room (ER) group
- Population-based group
Who delivered
Emergency room medical doctors
Setting
Emergency rooms - Five hospitals in the Seattle Area: Central and Eastside Hospital of Puget Sound, U Hospital of U of Washington, Harborview Medical Center, Overlake Hospital
FREQUENCY/DURATION
Duration
1 Year
RESULTS
- Helmets had an 85% reduction - Head injury. (Odds ratio 0.15, 95% CI 0.07 - 0.29)
- Helmets had an 88% reduction - Brain injury. (Odds ratio 0.12 95% CI 0.04-0.40)
CONCLUSIONS
Biases
| |
Attention |
X |
Masking/blinding |
|
Drop outs |
| |
Contamination |
|
Co-intervention |
|
Bicycle riders with helmets had 85% reductions in risk of head injury.
- ER data did not include cyclists wearing helmets who did not seek medical care
- ER control group limited to those who came to emergency rooms.
Terminology used in this document is based on two systems of classification current at the time the evidence-based literature reviews were completed: Uniform Terminology for Occupational Therapy Practice - Third Edition (AOTA, 1994) and International Classification of Functioning, Disability and Health (ICIDH-2) (World Health Organization [WHO], 1999). More recently, the Uniform Terminology document was replaced by Occupational Therapy Practice Framework: Domain and Process (AOTA, 2002), and modifications to ICIDH-2 were finalized in the International Classification of Functioning, Disability and Health (WHO, 2001).
This work is based on the evidence-based literature review completed by Beatriz C. Abreu, PhD, OTR, FAOTA, and colleagues. For more information about the Evidence-Based Literature Review Project, contact the Practice Department at the American Occupational Therapy Association, 301-652-6611, x 2040.
Copyright 2003 American Occupational Therapy Association, Inc. All rights reserved. This material may be reproduced and distributed without prior written consent.
