On Thursday, May 18, 2017 at 1:24:07 PM UTC-7, jbeattie wrote:
On Thursday, May 18, 2017 at 11:58:54 AM UTC-7, Frank Krygowski wrote:
On 5/18/2017 12:15 PM, jbeattie wrote:
On Thursday, May 18, 2017 at 8:46:49 AM UTC-7, Frank Krygowski wrote:
On 5/18/2017 12:32 AM, sms wrote:
On 5/16/2017 12:24 PM, Radey Shouman wrote:

By requiring an accident, you exclude the cases where a helmeted rider
took more risk than she otherwise would have, and had a crash she
would have avoided without a helmet.

And you have all the crashes that are not reported at all because the
helmet prevented a trip to the emergency room. Helmet effectiveness is
vastly under-estimated because there's no way to determine how many
people don't seek treatment because they have no injury because of the
helmet.

Bull****.

If there were vast numbers of concussions prevented by helmet use, the
number of bike-related concussions in the U.S. would not have risen at
the same time helmets surged in popularity.

From the article "Senseless" in the June 2013 issue of _Bicycling_
magazine: "Here’s the trouble. Stat #3: As more people
buckled on helmets, brain injuries also increased.
Between 1997 and 2011 the number of bike-related
concussions suffered annually by American riders
increased by 67 percent, from 9,327 to 15,546, according to the National
Electronic Injury Surveillance
System, a yearly sampling of hospital emergency
rooms conducted by the U.S. Consumer Product
Safety Commission (CPSC)"

Again, the needle is not even moving in the right direction.

Likewise, if there were lots of lives saved by helmets, bike fatalities
since (say) the mid-1980s should have dropped by a greater percentage
than pedestrian fatalities. But they did not, as shown by
http://vehicularcyclist.com/fatals.html
and http://vehicularcyclist.com/kunich.html

Ordinary helmets don't prevent minor TBIs, although they can prevent skull fracture and serious scalp injury. I've seen some scalp injuries that would make your skin crawl.

Citing to Kunich? Gawd. Go to MedLine: Clinical Surgery; Bicycle helmets work when it matters the most; (2017) 213 AMJLSU 2 413-417:

Results

A total of 6,267 patients were included. About 25.1% (n = 1,573) of bicycle riders were helmeted. Overall, 52.4% (n = 3,284) of the patients had severe TBI, and the mortality rate was 2.8% (n = 176). Helmeted bicycle riders had 51% reduced odds of severe TBI (odds ratio [OR] .49, 95% confidence interval [CI] .43 to .55, P .001) and 44% reduced odds of mortality (OR .56, 95% CI .34 to .78, P = .010). Helmet use also reduced the odds of facial fractures by 31% (OR .69, 95% CI .58 to .81, P .001).

Conclusion

Bicycle helmet use provides protection against severe TBI, reduces facial fractures, and saves lives even after sustaining an intracranial hemorrhage.

• The aim of this study was to assess the association of helmets with severity of traumatic brain injury and facial fractures after bicycle-related accidents.
• Results of our study strongly support our hypothesis that helmet use in bicycle riders with intracranial bleed is independently associated with reduction in overall facial fractures and severity of TBI.
• Injury prevention programs should advocate the use of helmets in bicycle riders especially in the teenage group where least compliance with bicycle helmet use was observed.


Who knows if it's accurate, but I would tend to trust a group of University of Arizona researchers and trauma doctors more than some dopey bloggers.

The "dopey bloggers" were simply posting government statistics, Jay.
Despite lots of studies replicating the 1989 helmet promotion paper by
Thompson & Rivara and getting vaguely similar results, the TBI cases
have _risen_ with massive helmet use; and the fatalities have not fallen
as fast as pedestrian fatalities. You may not like the guy who posted
the numbers, but those ARE the numbers!


The study you linked is very typical, and very similar to the Thompson &
Rivara study that served as its prototype. The T&R "85%"study has
gotten the most discussion in efforts to explain why its predictions
simply don't come true in the real world (and why its results are
officially disowned by the federal government); but the criticisms of
T&R apply to almost all studies on the same model. Here are some of them.

First, if you're studying helmeted vs. non-helmeted cyclists presenting
to ER, are you really studying similar groups? Fatalities are mentioned
above; but as John has noted several times, roughly a quarter of bike
fatalities involve blood alcohol above the legal limit. AFAIK only one
helmet study of this type included alcohol as a confounding factor, and
it found that alcohol use correlated with brain injury; helmet use did
not significantly correlate. More briefly, drunks don't usually wear
helmets, but they affect studies such as the one above.

In the T&R study, other reviewers showed that helmeted kids were seven
times as likely to be presented to ER compared to non-helmeted kids.
Why? In that case, it appeared that kids (and today, adults) in helmets
had significantly better medical insurance, and would appear at ER "just
in case." Non-helmeted kids that presented were in much more serious
crashes overall, since the uninsured probably saved money by treating
minor injuries at home. More briefly, insurance coverage is a
confounding factor that's normally ignored. Did the study above account
for it?

Other confounding factors are likely, such as crash details (wrong way
into an oncoming car, or slip on gravel?), economic status (which goes
beyond insurance), availability of transportation (poor people are less
likely to wear helmets and less likely to have an easy way to get to ER)
and more.

If these confounding factors could all be accounted for - something I
doubt is possible - I suspect these "case control" studies would much
more closely match the observed results on a national scale, which is
that helmets make no great difference overall.

Former pro rider Chris Boardman said "Helmets not even in top 10 of
things that keep cycling safe." They've been heavily promoted for over
25 years and the needle is still moving in the wrong direction, even for
the minuscule portion of serious TBI that happens to bicyclists. Why
are we still giving them any attention?

Because they prevent certain injuries. Skip the case studies and go to FEA:

Bicycle helmets are highly effective at preventing head injury during head impact: Head-form accelerations and injury criteria for helmeted and unhelmeted impacts; (2014) 70 ESACAP C 1-7

The protective effect of a helmet in three bicycle accidents—A finite element study; (2016) 91 ESACAP 135-143

There are all sorts of these studies. Not surprisingly, they prove that if you hit your head on a hard object, you're better off if you're wearing a helmet. That's kind of why we have helmets, no?

What I'm wondering is that I'm the one here that has had the most experience with traumatic brain injury and you and the helmet nuts are the one's telling me that I'm full of ****.

When I was taken to the hospital after being knocked out for over 5 minutes they gave me a complete set of X-rays and CAT scans. Since the only injury was a divot in my brow ridge they let me out the door without a question. About three years ago I had my brother to the same ER and asked the doctors why they didn't keep me overnight to check for concussion damage and he laughed in my face. They don't do that because concussion isn't a traumatic brain injury.

And other doctors have plainly said - concussion is usually worse than a minor skull fracture. The head protects itself by fracturing to reduce the speed of impact so that you DON'T get a concussion.

And yet a bicycle helmet is designed ONLY to reduce minor skull fractures. This means that the impact wearing a helmet is likely to give you the very worst effects of an impact.