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Posts Tagged ‘bmi’

Measuring Health Part 2:The Traditional Metric ‘M’

Any measurement of health must provide some sort of predictive value with regard to the likelihood that one will remain healthy. While the entire idea of screening tests is fraught with controversy–both false positives and false negatives bring with them real risks–there are still a number of health measurements in the realm of traditional medical care that have a proven value when trying to predict downstream adverse health events. The trick, of course, is to decide which ones matter, filter that group to come up with tests that are as close to universally available as possible, and then decide how much weight each particular test in the group of survivors should receive in the single cumulative metric that is then created. This measurement, call it “M”, will be one of the variables in our calculated health measurement.

Let’s start with the simplest of all medical inquiries, a medical history. More specifically, let’s include a brief family history in our calculation of M. While it is becoming increasingly easy to obtain a very accurate genetic profile that identifies very specific health risks, these genetic tests are both controversial and expensive. Until the very real societal issues of knowing your exact genome and the risks it includes have been worked out by both ethicists and elected government, we should take a simpler and more narrow approach and ask two very simple questions: Has anyone in your family died from heart disease? Has anyone in your family died from cancer? Equally simple follow-up questions (How young were they? What kind of cancer) would allow us to add risk (reduce M) or ignore the historical note since the disease is not hereditary.

From here we move to an equally spartan individual medical history. Again, just two questions in this part: Do you smoke? Do you drink alcohol? The negative effect of smoking on an individual’s health, both in the present and future tense, must be accounted for in any measurement of health. It weighs so heavily on what we know about future risks that we will see it as a negative integer in M. Too many studies to count exist pointing out the deleterious effect of excess alcohol consumption to count. One compelling study, The Eight Americas Study in PloS One, found alcoholism to be the single most powerful lifestyle variant after smoking when predicting the life expectancy of groups studied. A recently published study of Harvard men found that alcoholism was the greatest second greatest influence on the happiness of the men studied, just behind the presence of loving friendships. Unlike smoking, however, there is a volume component to alcohol consumption. Indeed, a modest intake actually INCREASES longevity, while no intake DECREASES longevity. So M will see a small bump from moderated alcohol intake, an equally small decrease for teetotalers, and a dramatic negative effect from heavy alcohol intake.

So far we’ve managed to obtain some variables underlying M through the use of simple inquiry, costing only the time it takes a subject to fill out a questionnaire. At least two other variables are as accessible and inexpensive: blood pressure (BP) and a measurement of body habits. Once upon a time you had to visit a doctor or hospital to get your blood pressure checked. Now? Heck, for $20 you can buy a reasonable accurate BP monitor and take your BP at home! Minute Clinics in pharmacies, health clinics in the workplace, and coin-operated machines in the local Mall now make it easy to get a BP without visiting a doctor. While there is ongoing controversy in the medical world about what constitutes Hypertension it is safe to say that health risks are higher with a systolic pressure >140 and a diastolic >90. Above or below these levels is our toggle for M, positive or more healthy for lower and the opposite for higher BP.

Using body habitus is controversial, mostly because the measurement that is routinely utilized is so inadequate. The Body Mass Index, or BMI, is wildly inaccurate when it is applied to the fit. 4-time winner of the CrossFit Games Rich Froning, arguably the fittest man on the planet, would be deemed obese at 5′ 10″ and roughly 195 pounds with a % body weight fat of around 4%. Ridiculous, huh? The temptation, of course, is to use % BW fat as the preferred method of measuring body composition risk, but measurements that are accurate enough to be useful tend to be very expensive and difficult to access. On the other hand, all you need to determine the waist/hip ratio is an 89 cent paper tape measure and a calculator. A waist/hip ratio of >1.0 is associated with an increased risk to health from myriad metabolic illnesses including diabetes and heart disease, especially in men. Greater health in M for measurements under 1.0, and progressively less as that number increases.

It is impossible to utilize all that modern medicine has to offer when it comes to measuring health without spending a little bit of money. Several simple blood tests can be obtained with or without the input of a physician. The presence or control of diabetes can be ascertained with a HbA1c and a fasting glucose level. In the presence of a normal HbA1c an elevated fasting glucose may indicate a problem with insulin sensitivity, so it is important to include both. While it is far from settled whether or not it is cholesterol itself which is responsible for heart disease there is simply too much evidence that serum lipids can help predict cardiac events to leave them out of any health measurement. Our basic health index should therefore include the basic measurement of total cholesterol, HDL, LDL, and triglycerides, and M should reflect the negative effect of elevated Total Cholesterol, LDL and triglycerides and the positive effect of a high HDL.

How should we put all of these together to come up with our traditional health variable, M? This one is fairly simple; there are a number of “risk factor” measurements online that are good models. I envision a rather simple form on which one would add up weighted values for the measurements above, arriving at a straight forward mathematical sum. The final formula is being developed with the assistance of cardiologists at my medical school alma mater, the University of Vermont.

 

Measuring Health Part 1: Rationale, Definitions and Background

In 2010 I had a bit of an epiphany. At the time I was a bit over 4 years into my CrossFit journey. It became painfully obvious that the genius that Greg Glassman had applied to physical fitness–a definition of fitness that invited measurement, and in turn the critical evaluation of the efficacy of different fitness programs–was nowhere to be seen in the fields of health and medicine. Indeed, an informal survey carried out in person by my friend Dr. Kathy Weesner and I made it clear that the majority of physicians couldn’t come up with an actionable definition for health despite the fact that we are charged as professionals with helping our patients become “healthy”.

At around this time Coach Glassman published a theory that health was precisely defined as “fitness over time”. In CrossFit Fitness is work capacity across broad time and modal domains. Fitness over years could be depicted as a 3-dimensional graph with axes time, work, and years. As I thought about his thesis, that a backward looking view of an individual’s fitness as defined by CrossFit was a proxy for health, I found myself with the feeling that the definition was intriguing but incomplete. In response I took it upon myself to develop a broader definition of health, one in which fitness was a primary, but not the sole marker or metric. That April I submitted a draft of my definition of health along with a new, broader base of proposed tests that would generate the data that could be used to measure an individual’s health. Over the years it has become clear that Greg and I are more in agreement than not, but a key CrossFit employee at the time had a fundamental disagreement with my thesis, and consequently the article was rejected by the CrossFit Journal. I published my draft here on Random Thoughts later that year.

For almost 6 years I have been mulling this over, threatening to return to the problem of defining and then measuring health in much the same way that Coach Glassman defined and then measured fitness. The quest was derailed by all of the usual time sinks of mid-life. In a humorous irony, the majority of my real, true free time was consumed by the task of helping my sons run their CrossFit Affiliate gym. It is time, now, for me to finish what I started in 2010 if for no other reason than to establish the provenance of the theory.

In order to effectively address any issue whatsoever it is first necessary to have a clear understanding of the definition of terms that may be important to the discussion. I made a similar statement in one of my earliest posts on the importance of understanding the difference between health, healthcare delivery (medicine), and healthcare finance. Here again I fall back on the genius of Greg Glassman: just as one cannot evaluate either fitness or fitness programs without first defining what it is that you are discussing when you say “fitness”, one must first have a definition of “health” before one can begin to measure it. What exactly is “health”? What does it mean to be healthy?

Let’s return for a moment to the physician survey that Dr. Weesner and I did in early 2010. During face-to-face meetings we asked groups of physician colleagues to give us their definition of “health” or “healthy”. The majority of the answers couldn’t have been less inspiring or more disappointing. Indeed, the most common answer was “I don’t know”! Not very comforting, that. The second most common answer was as anticipated: health is the absence of disease. In our American medical system of “disease care” this is an understandable response, of course, but as the basis for the development of a true measurement of “health” it is obvious on its face that this definition has never translated into any actionable metric. Why? Well for one it fails entirely to take into account the very real importance of “fitness”, the expression of health. More specifically, like fitness as a proxy for health, “absence of disease” also fails to address a key requirement for any measurement of health: there is no forward-looking predictive value to simply stating that you have no disease today.

A measurable, actionable definition of health is one that takes into account the degree that disease is present or absent at any given time. It must address physical fitness; to be without a named disease but to be unable to walk up a flight of stairs should not ever be construed as “healthy”. Of equal importance to these factors, any definition of “health” that will generate a meaningful metric must have a predictive value. Your Health Value should provide some measurement of your future likelihood of being disease free and fit. Our little survey of our physician peers did produce just such definitions. Given these requirements I propose that the following are actionable definitions that can be used in healthcare to create measurements in precisely the same way that Greg Glassman’s definition of fitness is used in that realm:

HEALTH: The state in which no infirmity of any kind suppresses, or has the possibility of suppressing the ability to express the full extant of an individual’s potential capacities.

HEALTHY: Able to perform in all ways at the farthest limits of one’s potential capabilities.

With these definitions we can move on to developing a “health metric”, one that can not only assess our present degree of health, but can also predict to some degree our ability to remain healthy. I believe this metric has three component parts: physical fitness as defined by CrossFit, well-being or emotional health, and a factor that addresses traditional or standard medical factors such as blood pressure, cholesterol, genetics and the like. Furthermore, I predict that these three variables are as evident and as logical for “health” as Coach Glassman’s definition is for fitness.

One can have an otherworldly degree of fitness as defined by CrossFit, but what good is it to have a 500 pound deadlift and the ability to run a 4:00 mile if your physical achievement is driven by self-loathing? By the same token, in addition to having a normal result in every conceivable medical test your countenance is as sunny as an 8 year old on vacation, your disposition so Zen-like that the Dali Lama himself wishes he were as happy and serene, but you can’t walk a mile. This surely cannot equal healthy. You are a world-champion long-distance runner, and yet you drop dead from a heart attack, unaware that you have a cholesterol of 800. Fit for sure, but hardly healthy. Fitness, well being, and modern health metrics all have a role in an actionable Health Measurement. Vigorous debate will be necessary to parse the relative weight given to each of these factors, but as I first proposed and wrote in April 2010,all three are clearly necessary components.

In short order I will offer follow-up posts that delve more deeply into each of these three components. I will include suggestions for what and how to measure them. I will conclude with a re-statement of my proposal for a single measurement of health with my suggestion as to the relative weight of the three variables, hopefully inciting the above-mentioned vigorous debate. By doing so I wish to document the originality and timeline of my proposal, acknowledge the intellectual debt owed to Greg Glassman for inspiring me, and reassert my contention that healthcare cannot reach its fullest potential without first agreeing on both a definition of health and how to measure it.