Re: Ontario Helmet Law being pushed through

Discussion in 'Road Cycling' started by Frank Krygowski, Jan 7, 2005.

  1. R15757

    R15757 Guest

    Frank K wrote in part:

    >R15757 wrote:
    >>
    >> Adults don't go to the ER for "skinned knees."

    >
    >You may think so. But according to "Bicycle Accidents; An Examination
    >of Hospital Emergency Room Reports..." by Stutts, et. al.,
    >Transportation Research Record #1168, the most common bicycling injury
    >being treated in an ER is a minor injury of the "Knee, lower leg,
    >foot". Of those injuries, nearly 90% are "minor."


    It's strange that in all my decades of riding
    and all the hundreds of high-mileage cyclists
    I have known, I have not known a single one who
    ever went to the ER for a minor injury.
    In fact most of the cyclists I know would have
    to be dragged into the ER if a bone was
    sticking out.

    When you speak of minor injuries to the
    lower leg, what you are speaking of primarily
    are lacerations requiring stitches,
    and sprains and strains requiring x-rays
    ("is it broken?"). Adults don't go to the
    ER for skinned knees, they certainly
    don't seek outpatient care for skinned
    knees. Stop being ridiculous.

    Now, it certainly is true that the vast majority
    of cycling related injuries are minor. This simply
    reflects the fact that cyclists face a
    highly elevated risk of minor injury compared
    to drivers (due to cyclists' solo wipeouts)
    while retaining a similar risk with regard to
    serious injury and death.

    Robert
     


  2. R15757 wrote:
    > Frank K wrote in part:
    >
    >
    >>R15757 wrote:
    >>
    >>>Adults don't go to the ER for "skinned knees."

    >>
    >>You may think so. But according to "Bicycle Accidents; An Examination
    >>of Hospital Emergency Room Reports..." by Stutts, et. al.,
    >>Transportation Research Record #1168, the most common bicycling injury
    >>being treated in an ER is a minor injury of the "Knee, lower leg,
    >>foot". Of those injuries, nearly 90% are "minor."

    >
    >
    > It's strange that in all my decades of riding
    > and all the hundreds of high-mileage cyclists
    > I have known, I have not known a single one who
    > ever went to the ER for a minor injury.
    > In fact most of the cyclists I know would have
    > to be dragged into the ER if a bone was
    > sticking out.


    There are three types of injuries, superficial (skinned knees), minor
    (i.e. severe lacerations, sprains, minor impacts, but no broken bones),
    and major. Superficial injuries are typically not treated at the ER.

    The problem of course is that you don't know how many of the minor
    injuries are not ever reported. You've learned by now about how Frank
    loves to misuse statistics. It is a certaintity that the minor injuries
    that he claims constitute 90% of ER visits, also constitute only a tiny
    percentage of all minor injuries incurred.
     
  3. Riley Geary

    Riley Geary Guest

    "R15757" <[email protected]> wrote in message
    news:[email protected]
    > Riley Geary wrote:
    >
    > >If you define "seeking medical attention" as showing up at an ER, the CDC
    > >data would suggest the ratio with respect to fatalities is more like 600
    > >or
    > >700-to-1.

    >
    > "Seeking medical attention" means just that.
    > The NEISS estimates a half million outpatients
    > seeking treatment for a bicycle-related
    > injury in addition to the half million ER visits.
    >
    > >>The number of ALL injuries is unknown
    > >> and unknowable, but a 5,000-to-1 ratio of total injuries-to-fatalities
    > >> seems reasonable. The ratio of hospitalizations to fatalities would
    > >> be what? About 60-to-1?
    > >>

    > >
    > >No, more like 25-to-1. The ratio of hospitalizations to fatalities for
    > >motor vehicle occupants is only about 6-to-1, and just 4-to-1 for
    > >pedestrians. OTOH, the ratio for non-traffic-related bicycle
    > >hospitalizations to fatalities is probably close to 50-to-1. Keep in

    mind
    > >this simply demonstrates that even among the more serious injuries

    requiring
    > >hospitalization, cyclists are much less likely to die from their injuries
    > >than either motor vehicle occupants or pedestrians (this is generally
    > >considered a good thing, though I suppose it may depend on your
    > >perspective).

    >
    > I want to be clear here. Are you saying that
    > motor vehicle occupants are hospitalized at
    > 4 times the rate of cyclists who have been
    > injured in a car-bike accident? Or of cyclists
    > who have been injured in all types of bicycle
    > accidents? Big difference obviously.


    I think you've got that backward, since overall cyclists have a
    hospitalization-to-fatality rate about 4 times that of motor vehicle
    occupants, not the other way round. For traffic-related cycling crashes,
    the ratio of hospitalizations to fatalities is about 22-to-1. The reason
    it's so close to the overall figure is because while about 75% of all
    bicycle-related hospitalizations are due to traffic-related crashes,
    something like 85% of all bicycle-related fatalities are similarly
    traffic-related.

    I should point out here that there is a considerable problem with the CDC
    fatality data in the distribution between traffic-related and
    non-traffic-related causes--due primarily to coding changes that took place
    when the CDC went from the IDC-9 definitions used from 1979-98 to the
    revised IDC-10 definitions it has been using since 1999. Prior to 1999, the
    portion of cycling fatalities coded as non-traffic-related slowly rose from
    about 10% to about 15%, reflecting the changing demographics of the cycling
    population, the increasing popularity of off-road cycling, etc, but then
    jumped to 23% during 1999-2000, increased to 26% in 2001, and 28% as of
    2002.

    This makes no sense given that the non-traffic-related portion of cycling
    hospitalizations also currently stand at about 25%, while they constitute
    nearly half of all cycling-related trips to an ER. Likewise, CDC
    traffic-related cycling fatalities generally ran 6-7% under the
    corresponding FARS numbers prior to 1999, but have been running about 18%
    under the FARS numbers since 1999. Conversely, total CDC cycling-related
    fatalities have averaged about 6-7% over FARS data, both before and after
    1999--except most recently in 2002, when they ran 15% over the FARS numbers.
    This strongly suggests that the CDC has traditionally had a problem
    miscoding some traffic-related cycling fatalities as non-traffic-related (or
    possibly even as non-cycling fatalities), but the problem became much worse
    when they went from IDC-9 to IDC-10 codes.

    >
    > It seems that the rate of hospitalization
    > would be similar for all parties involved in
    > an accident with a motor vehicle, whether the
    > injured party be on a bike, on foot, or a
    > passenger in a car. That is my suspicion
    > anyway.


    There are important physical differences involved in traffic crashes that
    influence potential outcomes for the victims involved depending on whether
    they are pedestrians, bicyclists, or motor vehicle occupants. MVO's
    obviously have the external protection offered by the vehicle itself in a
    crash, along with the substantial safety benefits offered by safety belts
    and (to a much lesser degree) air bags--which helps create a threshold
    effect where most potential minor to moderate injuries are avoided
    altogether, and even serious to potentially fatal injuries are moderated to
    a significant degree.

    In terms of the differences between cyclists and pedestrians, cyclists have
    a higher center-of-gravity, are less likely to be involved in high speed or
    nighttime collisions, and are much more likely to be just struck a glancing
    blow relative to pedestrians. For example, one of the most common car-bike
    collision types involves a motorist passing and then cutting off a cyclist
    with a right turn, either at an intersection or commercial driveway, causing
    the cyclist to hit the side of the car at a fairly shallow angle and with a
    fairly low closing velocity (~10 mph?), and usually resulting in nothing
    worse than a fall from the bike. Put a pedestrian in place of a cyclist in
    that sort of situation and they're likely to face a full-frontal impact by a
    3000+ lb vehicle traveling at 20+ mph, with results generally much more
    severe than for the cyclist. The higher center-of-gravity also means a
    cyclist is much more likely to roll over the hood of an impacting vehicle
    rather than end up under its wheels.

    >
    > >...but then couch sitters tend to suffer from a whole range of
    > >serious health risks later in life due to their >sedentary lifestyle;

    >
    > Yes of course. But everybody sits on the couch,
    > even avid cyclists. When we do so, we are at much
    > less risk of accidental injury than when we are
    > riding our bikes.
    >
    > >and
    > >even for traffic-related injuries, cyclists suffer far fewer fatalities
    > >relative to either serious injuries (~1 per 22 hospitalizations) or all
    > >injuries for which medical attention is sought (~1 per 400 trips to the
    > >ER)
    > >compared to either motor vehicle occupants (~1 per 85 ER visits) or
    > >pedestrians (~1 per 28 ER visits).

    >
    > "Traffic-related injuries?" So all those would
    > involve contact with a motor vehicle then?


    By the definition used by both the CDC and FARS, yes.

    > Otherwise it seems like you are just giving
    > another stat that shows that cyclists face
    > a greater likelihood of minor injury compared
    > to their driving counterparts (due to solo wipeouts),
    > IN ADDITION to facing a similar risk with regard
    > to motor-vehicle involved accidents.


    Not exactly. Cyclists face an enormously greater risk of minor injury
    relative to either motor vehicle occupants or pedestrians, but not
    necessarily when it comes to serious or fatal injuries.

    Of course, the same could just as easily be said about basketball, soccer,
    skiing, ice skating, or any number of other outdoor activities. If someone
    finds the prospect of an occasional bit of road rash or other minor injury
    too terrifying to contemplate, then they probably should resign themselves
    to a life of couch sitting.

    >
    > >Granted, even though a disproportionate number of those ER visits are due
    > >to
    > >juvenile cyclists, and thus have little real relevance to adult cycling
    > >conditions.

    >
    > Very true, although I suspect this is true even
    > if the kids' injuries are culled out. A disproportionate
    > number of the "trivial" ER visits belong to kids as well.
    > Adults don't go to the ER for "skinned knees."


    OK, for traffic-related injuries suffered by adult cyclists 16 or older, we
    have 1 fatality per ~17 hospitalizations and ~250 trips to the ER.

    >
    > >> But "pedestrian
    > >> accidents" (unintentional falls while walking) are by far the
    > >> number one cause of ER visits across all age groups. Pedestrians
    > >> in the ER are hospitalized far less often than cyclists.
    > >>

    > >
    > >Not according to the CDC data--unless you're including
    > >non-transportation-related falls around the home, >etc.

    >
    > Well, yeah, we include non-transportation-
    > related cycling injuries don't we? Or do
    > we simply classify ALL cycling accidents as
    > "traffic-related?"


    No, but nearly all cycling injuries are classified as transportation-related
    since the bicycle itself is considered a (non-motorized) vehicle--the
    difference here is whether a motor vehicle is involved or not (which means
    bike-only, bike-bike, bike-ped, and similar crashes are all considered
    transportation-related, but not traffic-related, at least according to FARS
    and CDC criteria). The only exception would be for any injuries sustained
    while making repairs or otherwise using a bike in a non-transportation
    capacity (e.g. having a parked bike fall on you rather than you falling off
    a bicycle in motion).

    > If you look at the CDC
    > data (which I linked to from your site--great
    > resource, thanks), you see that unintentional
    > falls while walking around (in the park, across
    > the street, in the home, whatever) are the
    > number one cause of injury across all age groups.


    Very true, but most of those are actually falls around the home (e.g.
    falling off a ladder, slipping in the bathtub, tripping on a rug, falling
    out of bed, etc) rather than falls associated with walking somewhere. It's
    also worth pointing out that unlike the case with cycling injuries, serious
    injuries associated with simple falls are overwhelmingly associated with the
    elderly portion of our population--over 2/3 of such hospitalizations and
    about 3/4 of such injuries resulting in death occur to those 65 or older
    (but less than 1/4 of all such ER visits).

    >
    > >Total ER trips by
    > >pedestrians (as defined by the CDC, both traffic-related and
    > >non-traffic-related) are only about 1/3 the number of bicycle-related ER
    > >trips (~175k vs ~500k/year), even though pedestrians account for slightly
    > >more total hospitalizations than bicyclists (~24k vs ~19k/year), and

    roughly
    > >8 times as many fatalities (~6000 vs ~750/year). But then, that is the
    > >sort
    > >of ratio relationship we would expect where one type of activity tends to
    > >produce a much larger fraction of serious to fatal injuries compared to
    > >some
    > >other activity.

    >
    > Well, you have to define "pedestrian" very
    > narrowly to get that ratio.
    >


    Granted. It would be nice if the CDC provided a breakout of
    "non-transportation" pedestrian injuries resulting from simple falls, but
    the online database doesn't appear to offer that option.

    Riley Geary
     
  4. On Mon, 31 Jan 2005 15:44:24 GMT, "Steven M. Scharf"
    <[email protected]> wrote in message
    <[email protected]>:

    >There are three types of injuries, superficial (skinned knees), minor
    >(i.e. severe lacerations, sprains, minor impacts, but no broken bones),
    >and major. Superficial injuries are typically not treated at the ER.
    >The problem of course is that you don't know how many of the minor
    >injuries are not ever reported.


    You also do not know how many of those which make it to ER are
    actually minor, e.g. ear cuts, which bleed spectacularly, or
    concussions, which are often admitted for overnight observation even
    though they amount to nothing more than a headache. Concussion makes
    up the vast majority of the "brain injury" cases reported in the
    helmet literature.

    >You've learned by now about how Frank
    >loves to misuse statistics.


    Whereas you love to - what - avoid them altogether? Or is that just a
    coincidence?

    >It is a certaintity that the minor injuries
    >that he claims constitute 90% of ER visits, also constitute only a tiny
    >percentage of all minor injuries incurred.


    Question: who actually cares about minor injuries anyway? We have a
    helmet promotion charity which claims over 100,000 children suffer
    cycling head injuries annually, but since less than 5% of those make
    it as far as an actual hospital (rather than being treated by
    first-aiders or in minor injury clinics) one could justifiably
    question how worried we ought to be about them.

    Guy
    --
    May contain traces of irony. Contents liable to settle after posting.
    http://www.chapmancentral.co.uk

    85% of helmet statistics are made up, 69% of them at CHS, Puget Sound
     
  5. On Mon, 31 Jan 2005 17:21:29 -0500, "Riley Geary"
    <[email protected]> wrote in message
    <[email protected]>:

    >One other factor I haven't
    >mentioned yet is the question of how reliably helmet use data is actually
    >being recorded for bicyclists on the police accident reports in Florida (and
    >elsewhere).


    Good point. At least one study I have read assumed that any head
    injured cyclist for whom helmet wearing was not recorded, was not
    wearing a helmet. This was at least made clear in the discussion.
    How many others have made the same assumption and not stated it?

    Guy
    --
    May contain traces of irony. Contents liable to settle after posting.
    http://www.chapmancentral.co.uk

    85% of helmet statistics are made up, 69% of them at CHS, Puget Sound
     
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