It's mud-luscious Spring: Get Outside and Play!

Spring is a month old.  Earth Day was last week.  It's time to celebrate play in the great outdoors.

Outdoor play for kids:  there's nothing like it.  It's a theme I'll be investigating and coming back to continuously as I write this blog.

The American Academy of Pediatrics recommends one hour of moderate to vigorous physical activity (MVPA) a day for youngsters; there are technical definitions for 'moderate' and 'vigorous,' but the terms roughly are equivalent to the energy expended in walking and running, respectively.


Kids in America are getting a lot less MVPA these days.

A couple of weeks ago, I had the good fortune of being asked by my friends at the Leave No Child Inside Collaborative of Ohio to spend the afternoon with them as they profiled the benefits of outdoor play for children.  The story can be found here.

I spent some time discussing the findings in a  2010 article in the Journal of Epidemiology and Community Health.  This study reviewed the well-known decline of physical activity time in children and adolescents in most developed countries.  It went on to survey the literature demonstrating that time outdoors is positively associated with physical activity in kids. Literally, if the only intervention made was to have children outside as opposed to indoors, their average MVPA increases.  Not surprisingly, more MVPA leads to lower rates of child overweight and obesity.

This is science merely validating what Grandmothers' common sense has always known, a confirmation of that old saw that middle agers' like me enjoy saying:  "when i was a kid, my mom just pushed me out of doors and told me not to come back inside until dinner.'  But maybe things were different back then, so the question  in 2012 is:   how do we get our kids outside, so they can increase their MVPA?

The 2010 study looked over five years at predictors of time spent outdoors in children.  Many factors were anazlyzed:  yard size, owning a dog, number of siblings, availability of outdoor play space, etc. Among the most powerful predictors found were parental encouragement and supervision.  These were more powerful predictors of outdoor time than, say, availability of playground space.  This influence of adult behavior on child play was especially true for older children.  In other words, getting outdoors with your kids gets them outdoors and active.  Actions speak louder than words.  Grandmothers in 2012 may just need to go outside along with their kids, instead of simply pushing them outside.

It's a beautiful, cool but sunny day here in Central Ohio, and it rained yesterday.  There's a mud puddle somewhere for your kids (and you) to play in or near.  Get outside.

e.e. cummings (and I) would love to see you there.

[in Just-]

BY E. E. CUMMINGS

in Just-

spring          when the world is mud-

luscious the little

lame balloonman

whistles          far          and wee

and eddieandbill come

running from marbles and

piracies and it's

spring

when the world is puddle-wonderful

the queer

old balloonman whistles

far          and             wee

and bettyandisbel come dancing

from hop-scotch and jump-rope and

it's

spring

and

         the

                  goat-footed

balloonMan          whistles

far

and

wee

Screening for Sudden Cardiac Death: Pitfalls, Part I

It has been a busy week.....for me and for the sporting world!  The NHL playoffs have begun and the Bruins are already out; the NBA playoffs have commenced, and I'm sorry to see Derrick Rose go down with a season ending injury.  Andrew Luck has gone as the #1 draft pick, as predicted, and one of the rarest of feats in baseball, the perfect game, was accomplished by the White Sox pitcher Philip Humber.

However big all this news has been in the United States, I think it is dwarfed by the week's events in the world of football, that is, the kind without shoulder pads and helmets.  As I write, England awaits The Derby on Monday, which looks to decide the English Premiership Championship. Last weekend, Real Madrid beat Barcelona in a Spanish La Liga match that probably determined their league's championship.  Then, both teams went on to be upset in agonizing fashion in their respective Champion's League semifinals.

To one young man in my household, who's a big fan of Barca's Lionel Messi, it was a tough week.

I'm finally getting a chance to return to this blog.  All this football (er, soccer) has me thinking about an earlier blog post where I began a discussion about sudden cardiac death in young athletes, and the potential for screening to prevent this tragedy.  Thankfully, this was not a week in the sporting world with catastrophic outcomes like the sudden cardiac death of Piermario Morosini.

The issue of screening young athletes for conditions which could predispose them to sudden cardiac death (SCD) is a contentious one.  I'm from Western Michigan, and just this spring near my hometown Wes Leonard collapsed and died after a high school basketball game.  Deaths like these are always devastating.  When I read these stories--I suspect when anyone reads these stories-- there is a natural desire to do something to prevent this from happening again.  Just this last week, a good friend of mine from grade school and high school was asking me what I thought about his request that a local doctor perform a pre-season electrocardiogram (a.k.a. 'EKG' or 'ECG') on his daughter.

So. let's discuss the use of EKG's in the screening of young athletes in this country to prevent SCD.  This will require some discussion of statistics.

First, it is important to define the population one wants to be screened.  In general, athletes 35 years and older incur different risks than younger athletes.  The vast majority of middle aged and older athletes who die in the middle of a contest have had a myocardial infarction or "M.I.".  Screening this population is actually a fairly well defined proposition, and can often involve treadmill testing, looking at risk factors such as blood pressure, high cholesterol, and the like.

The question of how to screen younger athletes such as Morosini or Leonard is a different one, as the causes of their SCD are rarely from an M.I.  Younger athletes who suffer SCD typically have a different set of predisposing risk factors, with esoteric names such as 'hypertrophic cardiomyopathy,' 'long QT syndrome,' "arrhythmogenic right ventricular dysplasia," and "Marfan syndrome."   Reggie Lewis, the Boston Celtic, died of hypertrophic cardiomyopathy, and Flo Hyman, the Olympic Volleyball player, died of Marfan syndrome for instance.

We'll attempt to screen younger athletes then for this constellation of illnesses.  Does a screening test exist?  As things currently stand in the United States, whether a family is aware of it or not, the annual ritual of the preparticipation physical examination (PPE) is, among other things, a screening test for conditions that could cause SCD.  And it is a very poor one with a sensitivity of about 2.5%.  We'll discuss sensitivity in a moment, but for now it is sufficient to say that that makes the PPE a very poor screening test.  There are no hard numbers, but one might begin to call a test 'good' when the sensitivity might be over 90%; so 2.5% is really abysmal.

Two other tests have been looked at in some depth, including echocardiograms (an ultrasound of the heart) and the EKG.  Of the two, there exist much more data looking at the use of EKGs in screening for SCD. For instance, in Italy a group led by Domenico Corrado has been screening competitive athletes with EKGs since the 1970s.   In part II of this post, which I'll be putting up on the blog later this weekend, we'll be looking in greater depth at  screening EKGs.  Before I close this post, a brief discussion of sensitivity and specificity, parameters that describe the accuracy and reliability of a screening test, is in order.

Sensitivity and Specificity are statistical measures of the performance of any test.  There is a formal definition for each parameter, and a way of calculating these measures for tests ranging from the serum cholesterol test to the mammogram to the EKG.   A good way of thinking of these parameters conceptually however uses the mnemonics 'SNout' for seNsitivity and 'SPin' for sPecificity.  If you get a Negative result on a test with high seNsitivity, you can be reasonably assured you have 'ruled out' the disease you are screening for (hence the 'out' in 'SNout').  Conversely, if you get a Positive result on a test with high sPecificity you can be reasonably assured you have 'ruled in' (hence the SPin) the disease you are screening for.

An ideal test will maximize both specificity and sensitivity, but you can't have your cake and eat it too in the world of statistics:  if you want to improve the specificity of a test, you will tend to reduce its sensitivity, and vice versa.  There will always be a trade off between specificity and sensitivity.  Issues of civil liberty aside, we have decided in the United States to use a low specificity way of screening for airline terrorists (we make everyone go through the scanner) in an attempt to keep sensitivity rather high (we want to make sure we don't miss the one terrorist who might get on the plane).  Many screening tests will make this implicit trade off:  they will maximize sensitivity at the cost of lower specificity, to ensure they don't miss a disease.  The implicit cost of this method is to ensure a decent rate of false positives:  the strange finding seen on mammogram that ultimately needs a biopsy to verify it is benign, or 'ok'; the disgruntled, aggrieved families who wonder why on earth their sweet grandmother had been patted down by the TSA.  These are cases of false positives, consequences in some sense of the high sensitivity of the screening test involved.

There is one more concept to introduce now, before closing for the moment.  The ultimate predictive value of a medical screening test is influenced by one more parameter:  the underlying prevalence of the disease being screened for in the population.  Prevalence is the frequency of a given disease in the population.  For instance, we can say (sadly) that the current prevalence of obesity in the United States is 35.7%:  more than a third of the adults in the U.S. are obese!!!

Getting back to the connection between prevalence and the testing performance parameters of sensitivity and specificty:  for the statisticians out there, Bayes' Theorem is at play here.  The general principle is that when screening for a rare disease, even tests with high specificty and sensitivity will have fairly poor predictive value.  Put more simply, using even a decent test to look for a needle in a haystack will give you crappy results.   What makes a test 'good' is not just intrinsic to the test itself (e.g. its specificity and sensitivity); it is dependent on the choice of population in which to use it.  Put simply, one can potentially make even a 'good' test bad by choosing to use it in a low prevalence population.  In many ways, that is the crux of the problem for the issue at hand.

We'll close for now, but in the next post we'll begin to look at the sensitivity and specificity of EKGs for screening for the conditions underlying SCD, and the prevalence of those conditions in the young athletic population.  And then we'll begin to see whether it makes any sense to use screening EKGs to try to prevent these horrible outcomes.

Biking: Part One (of many installments)

I've been a bike commuter for over twenty years, from my days in medical school in Boston, to my work with the Banana Slugs of the University of California, Santa Cruz, to my current home of Columbus, Ohio. I admire my friends who bike recreationally.  I don't.  I have never ridden a "century," or rode in a bike race, a criterion or a tour.  I commute.

I enjoy bike commuting for many reasons.  I enjoy the health benefits, and the ease (and cost:  free!) of parking when I reach my destination.  I also enjoy being in nature, as opposed to being enclosed in a car.  I partake of a similar feeling I think to what some of my motorcyclist friends describe as the experience they enjoy on their 'bikes'; you can feel the elements:  the wind, the rain, the coolness that lingers in a dip in the road on a morning ride.  And I do so without the gasoline expense.

The pace of a bike ride is, as well, special.  You can cover miles much more easily than you can walking or even running, but the speed of course is still much less than a car. So, you can actually experience the neighborhoods you bike through in a much more intimate way than when driving, and you can see much more of the community than you could if you were just walking.  What's more, you're not allowed on the interstate on a bike, so by necessity you must go through the neighborhoods, the back roads.  I have, when moving to a new community, learned the lay of the land much more easily on a bike than in a car.

I was biking to work today and thinking about this community Kit, Momo, Claire and I moved to a year and a half ago. It's an urban environment with potential for kids and families to be active, but it's still far too structured around the car.

There's a reasonable number of bike routes in this community, that I use to go to clinics downtown and in Westerville.  There's a pretty nifty one I access to get across town to take my public health classes at Ohio State.  Some of these routes incorporate sections that are truly bike paths, but the bulk of the routes are signed roads.  There's a stretch on Sunbury Road, as I take the road section of the Alum Creek trail up to Westerville, where I have flashbacks of Renee Zellwegger's character in Jerry Maguire:

Driving us out to Manhattan Beach.
All those tiny streets.
Playing chicken with the traffic.
Your life flashing before you.

I'm looking forward to when the southern and northern part of that bike path hook up, and I can stay off the roads entirely.

And back to the pace of a bike commute.  On my way home, I travelled by a sign teaching me about an athlete of another generation I never knew before

Marshall "Major" Taylor was an American cyclist who overcame discrimination, as so many African-American athletes have in history, to win the world one mile track championship in 1899.  A four mile stretch of the Alum Creek trail is dedicated to Taylor, who grew up in the midwest.  I never knew of him before I biked past this sign.

In terms of the medical research I like to discuss in this blog, there
is too much about biking to review in one posting; hence I anticipate many installments, as this post's title indicates.  One article I did want to mention is a 2005 study from Denmark where children and adolescents were evaluated for their physical activity levels and their physical fitness levels.

Physical activity and fitness are different constructs, the former
assessing for calories burned and the latter for ability to perform
physical tasks at moderate to vigorous levels.  In many studies of children, physical activity will be measured with pedometers or accelerometers, devices which the children can wear and which record for instance the number of steps they will take in a day.  Physical fitness is typically measured in the lab, with different tests available to determine an individual's V02 max.

Active travel to school is a fantastic way for kids to get, well, active, and is one this generation uses far less frequently than mine did.  Whether it's on foot or by bike, kids' commuting to school on their own is wonderful.  And as far as measures of sheer physical activity go, this study found that biking or walking will give similar results.  However, the study went further, to look at measures of physical fitness, an outcome not typically evaluated in these studies.

The study authors looked at a large group of children (529 individuals with an average age of 9.7) and adolescents (390 individuals with an average age of 15.5 years) and measured their V02 max on a maximal cycle ergometer.  They gave these same individuals a questionnaire about their typical mode of travelling to school, and validated the results of this questionnaire by quantifying their physical activity level using accelerometers (done in 531 of the participants).  This validation is useful since it has been found that for these types of questions people might overestimate their activity level using only a questionnaire.

Compared with walkers and kids using passive transport (i.e. cars/buses), bicycling kids were significantly fitter, and were nearly 5 times as likely to be in the top tier of fitness than their counterparts.  This stands to reason, as you will typically drive your heart rate to higher levels on a bike than you will when walking.

So, the message for our kids should be walk or bike to school.  They are both great! But if you have a goal of getting fit for a sport, bike commuting rules!

Sudden Cardiac Death in Young Athletes: Screening and AEDs

Those of you who follow football (or what we with American 'exceptionalism' call 'soccer') will be familiar with the tragic story of the Italian footballer Pieromario Morosini  who collapsed and died over the weekend.  A similar story with a happier, almost miraculous, ending occurred last month when Fabrice Muamba of the Bolton Wanderers collapsed on the pitch when playing against Tottenham Hotspurs.  He survived.

In both cases, Automatic External Defibrillators (AEDs) were used, though I understand there was a several minute delay in Morosini's case. AEDs are a wonderful technology, and can be invaluable in these cases of "cardiac arrest" (which is less a medical diagnosis than a layperson's description for what were probably events known as "ventricular tachycardia" or "ventricular fibrillation").  They are extraordinarily easy to use: it has been demonstrated that sixth graders can employ the devices as readily as trained paramedics.

I have had the dubious privilege of using an AED on a plane once, on an elderly woman who had collapsed.  The stewardesses summoned a doctor on the plane, and I responded.  And thank God, there was an AED.  The device brought the patient back.  I was so grateful. And I can vouch for the fact that they are very easy to use, even under the most stressful of circumstances.

There is great controversy over the question of screening for cardiac abnormalities, whether the population is professional football players or young recreational athletes.  Ironically, some of the most impressive work in this area has come from the Italian research group headed by Domenico Corrado.  I've also greatly enjoyed the work of Jonathan Drezner in this area, and I plan in an upcoming blog post to talk about this issue and some of Dr. Drezner's work in particular. This type of screening is called "secondary prevention" in medicine, and amounts to a type of Preventive Medicine which is designed to catch a disease in its early stages, before serious outcomes (such as death) can occur.  In other words, do we have a test that could identify athletes such as these two football players before they collapse?  The answer is 'yes,' but with some big qualifiers.

Screening with an electrocardiogram (EKG) or an echocardiogram can be done, and may have found underlying diseases in Morosini or Muamba which could have indicated they were at risk for death or near-death events.  There are problems with such screening, however, and that is what I intend to discuss in the near future.

For now, I am filled with sadness for the family of Morosini, and for Muamba, whose career is very likely over.  The words of A.E. Housman, from his poem To an Athlete Dying Young come to mind:

Today, the road all runners come,
Shoulder high we bring you home,
And set you at your threshold down,
Townsman of a stiller town.


Let's say a prayer for Pieromario Morosini and his family, who has left us; and a prayer for the continued
recovery of Fabrice Muamba.

Walking is Arguably the Best Exercise

There is a great article in the NY Times I read yesterday morning on the value of walking:
http://www.nytimes.com/2012/04/13/nyregion/walking-helps-many-fit-in-exercise.html
Kit, the kids and I were just in NYC, and I can vouch for the urban gym which is the Big Apple.


Whereas here in Columbus we run most of our errands in our cars, it seems like the typical New Yorker goes to the shop or even to work on their own two feet.The article states, "Health experts recommend walking 10,000 steps a day to maintain weight, reduce blood pressure and cut the risk of cancer and heart disease. With our pervasive driving culture,many people struggle to meet that ideal daily quota. New Yorkers, however, live in a city where walking is a natural part of life."


The walking pays off.  Central Park, Manhattan, Brooklyn:  so many lean people, so many fewer overweight folks to be seen on the street.  Our friend Norman has essentially switched over from being a gym rat to a home pilates/urban walker; and he looks fabulous.


Too often I see people in my working life state a desire to workout and lose weight, but they seem unaware of the value of walking.  In fact, it would be far better for most folks to commit to walking 10000 steps a day than to a membership at a gym.


Fitness is not complicated.