Statistics?

"Mike S." <mikeshaw2@coxDOTnet> wrote in message news:Vx0db.23422$vj2.13489@fed1read06...

Quoted message said:

Hey, anyone ever track the severity of crashes that cause helmeted

riders

Quoted message said:

going to the hospital? Has there been a reduction in the severity of accidents, even though there
hasn't been a drop in the actual number

of

Quoted message said:

cases?

Mike:

If you have the energy, you can search the medical literature for this info. Try:

ncbi.nlm.nih.govPubMedOpen ↗

Search for "bicycle helmet" as an easy starter. You'll find several hundred papers on the issue,
mostly re children, but plenty of adult studies. I pasted a review article below.

Readers who scrutinize the studies' methodologies may disagree with the conclusions, but the
conventional wisdom says injury severity is reduced with helmets.

Cheers,

Tom

Cochrane Database Syst Rev. 2000;(2):CD001855. Related Articles, Links

Ann Emerg Med. 2003 May;41(5):738-40.

Helmets for preventing head and facial injuries in bicyclists.

Thompson DC, Rivara FP, Thompson R.

Pediatrics; Harborview Injury Prevention & Research Center, University of Washington, Box 359960,
325 Ninth Avenue, Seattle, WA 98104, USA. [email hidden]

BACKGROUND: Each year, in the United states, approximately 900 persons die from injuries due to
bicycle crashes and over 500,000 persons are treated in emergency departments. Head injury is by far
the greatest risk posed to bicyclists, comprising one-third of emergency department visits,
two-thirds of hospital admissions, and three-fourths of deaths. Facial injuries to cyclists occur at
a rate nearly identical to that of head injuries. Although it makes inherent sense that helmets
would be protective against head injury, establishing the real-world effectiveness of helmets is
important. A number of case-control studies have been conducted demonstrating the effectiveness of
bicycle helmets. Because of the magnitude of the problem and the potential effectiveness of bicycle
helmets, the objective of this review is to determine whether bicycle helmets reduce head, brain and
facial injury for bicyclists of all ages involved in a bicycle crash or fall. OBJECTIVES: To
determine whether bicycle helmets reduce head, brain and facial injury for bicyclists of all ages
involved in a bicycle crash or fall. SEARCH STRATEGY: We searched The Cochrane Controlled Trials
Register, MEDLINE, EMBASE, Sport, ERIC, NTIS, Expanded Academic Index, CINAHL, PsycINFO,
Occupational Safety and Health, and Dissertations Abstracts. We checked reference lists of past
reviews and review articles, studies from government agencies in the United States, Europe and
Australia, and contacted colleagues from the International Society for Child and Adolescent Injury
Prevention, World Injury Network, CDC funded Injury Control and Research Centers, and staff in
injury research agencies around the world. SELECTION CRITERIA: Controlled studies that evaluated the
effect of helmet use in a population of bicyclists who had experienced a crash. We required that
studies have complete outcome ascertainment, accurate exposure measurement, appropriate selection of
the comparison group and elimination or control of factors such as selection bias, observation bias
and confounding. DATA COLLECTION AND ANALYSIS: Five published studies met the selection criteria.
Two abstractors using a standard abstraction form independently abstracted data. Odds ratios with
95% CI were calculated for the protective effect of helmet for head and facial injuries. Study
results are presented individually. Head and brain injury results were also summarized using
meta-analysis techniques. MAIN RESULTS: No randomized controlled trials were found. This review
identified five well conducted case control studies which met our selection criteria. Helmets
provide a 63%-88% reduction in the risk of head, brain and severe brain injury for all ages of
bicyclists. Helmets provide equal levels of protection for crashes involving motor vehicles (69%)
and crashes from all other causes (68%). Injuries to the upper and mid facial areas are reduced 65%.
REVIEWER'S CONCLUSIONS: Helmets reduce bicycle-related head and facial injuries for bicyclists of
all ages involved in all types of crashes including those involving motor vehicles.

Mike S. asked: << Hey, anyone ever track the severity of crashes that cause helmeted riders going to
the hospital? <snip.>>

No, and that is a big problem.. Being in the hospital is the parameter. One person's near-death
experience is another person's bonk on the head. Do parents rush their kids to the ER after the
slightest fall off the bike? Do affluent folks, with access to good health care, visit the ER
more often than poor folks? Do people who buy helmets ride differently than people who don't?
Lots of unanswered questions...Good guess is that helmets do work to some degree, how much is
waaay up for debate.

Robert

Robert "R15757" <[email hidden]> asks: "Do affluent folks, with access to good health care, visit
the ER more often than poor folks?"

As an ER doc I can answer this easily without having to do any type of study. The answer is a big
NO. In fact, just the opposite is the case. Poor people are much more likely to go to the ER than
affluent people and for more trivial reasons. This does not, of course, change the issue of
selection bias in helmet studies that Robert raises but it clearly runs in the opposite direction.

--
Mike Murray MD

"Mike Murray" <[email hidden]> wrote in message
news:Vioeb.639153$YN5.488814@sccrnsc01...

Quoted message said:

Robert "R15757" <[email hidden]> asks: "Do affluent folks, with access to good health care, visit
the ER more

often

Quoted message said:

than poor folks?"

As an ER doc I can answer this easily without having to do any type of study. The answer is a big
NO. In fact, just the opposite is the case. Poor people are much more likely to go to the ER than
affluent people and for more trivial reasons. This does not, of course, change the issue of
selection bias in helmet studies that Robert raises but it clearly runs in the opposite direction.

--
Mike Murray MD

Hey Mr. MD: have you tracked in any way the kinds of injuries that people riding bicycles come in to
the ER with? I'm interested in what you've seen
vs. actual statistical analysis.

Mike

Thomas J. McGuire said:

Thompson DC, Rivara FP, Thompson R.

What's our score for this study in this thread? I count three.
--
David Damerell <[email hidden]> Distortion Field!