BMI Measurements Inaccurate But Still A Government Gold Standard



Everyone needs to read this NY Times article and then think about how inane the concept has become.

The Body Mass Index or “BMI” is used as a measure of a person’s body weight. If your BMI is between 18.5 and 25, you’re normal. More than 25 and you’re overweight. More than 30 and you’re obese. The measurement is based on a person’s weight and height, but it was originally created in the 1800s to measure human growth – not as a measure of a person’s ideal body weight or health. More recent studies show that people considered “overweight” using the BMI measurement are healthier than those who are at the lower end of the “normal” measurement. One study shows that likelihood of death increases with a BMI of less than 23. BMI doesn’t account for the distribution of body fat (abdominal fat is less healthy), BMI falsely classifies muscular individuals as “obese”, and even the CDC has recommended that doctors not use BMI as a diagnostic tool.
Yet what is one of the things our government requires that doctors calculate on every patient’s chart in order to meet “meaningful use” criteria?
You guessed it.
A BMI measurement.

This is what happens when inmates run the asylum.

The reason that we are being required to measure BMI isn’t because a patient’s BMI has any meaningful clinical use … it’s that the BMI can be measured. If it can be measured, it can be tracked. If it can be tracked, then people (essentially health care providers) can be manipulated and penalized if some arbitrary number on a meaningless scale isn’t reached.

Think about it. If we tried to find other substitutes for “health”, they would be difficult to calculate. How many calories does a patient eat? How much alcohol does a patient drink in a day or week? How much exercise does a patient get each day or week? There’s no standard way to objectively quantify or objectively measure any of those criteria.

Instead the government sticks with something easy to measure – even though it has no bearing on a patient’s health. With a little propaganda, the government can make all the patients who don’t know any better think that BMI really is a useful measure of health. Then, if the BMI isn’t calculated and put on the patient’s chart, it gives the government a means to reduce or deny payments to the healthcare providers.

Calculating a BMI and asserting that it is a representation of health is like measuring the number of clouds in the sky at 3PM each day and claiming that a higher number of clouds is an accurate representation of good government.

The scary thing is that another industry has been making similar assertions for years and certain village idiots just continue to believe the misinformation.

Patient satisfaction scores have long been asserted to be a surrogate measure for healthcare quality. Of course, those assertions are made by corporations which receive hundreds of millions of dollars each year from hospitals so that they can compare one hospital to another … on a statistically invalid and entirely misapplied metric. Studies prove that higher satisfaction is associated with higher healthcare costs and almost double the amount of patient deaths. Recall the story about the Texas neurosurgeon who maimed and killed patients yet who had great scores (which were suddenly removed by the Healthgrades staff when the story broke). Healthgrades knows its data are inaccurate, but persists in collecting and disseminating inaccurate and potentially dangerous information.
Junior high statistics classes teach twelve year olds that inadequate sample sizes automatically prevent you from making valid conclusions from the results. Want a real life example? Open up a pack of skittles, take out 5 pieces of candy, note the proportion of colors, and then see if those proportions match the proportions of colors left inside the pack.

Despite the woefully inadequate sample sizes and scientific evidence showing that these measures have no bearing on patient outcomes, the same government that relies upon BMI measurements as a representation of health is going to rely upon patient satisfaction scores as a measure of healthcare quality … and will reimburse hospitals less for care when they have lower satisfaction scores. Hospital administrators and hospital governing boards swallow this obviously inaccurate and misleading information like high school kids sucking beer through a beer bong — all in the name of profits with little regard to the adverse effects on patient health.

It is refreshing to see that hospitals are starting to be held accountable for these decisions. It is easy to prove administrative negligence and hospital board liability when bad faith actions harm patients so that hospitals can earn more money.

After all … the sun is shining. That means that BMI measurements and payment for satisfaction are bad government policies that no one should follow.

I’m a scientist. I know these things.


  1. Patient “satisfaction”?
    I thought they wanted excellent care?
    Is anyone “satisfied” by prevention they don’t see, illnesses that don’t happen, resistant UTI’s that don’t happen because I said “no” to unnecessary antibiotic prescriptions.
    Are they satisfied when I won’t give then 130 Percocet for a twisted ankle (despite a 15 minute discussion on the adverse effects of their habit…nope, they don’t want my reasoning either)?
    Satisfaction is a consumerist term.
    It has nothing to do with medical practice.
    Shame on our bosses and administrators for buying into this impossible metric.
    And shame on them for hanging excellent doctors out to dry for not being “satisfactory”.
    Excellent care is easy to recognize.
    Review some charts. Examine some outcomes (controlling for the constant that bad stuff happens no matter what and that the patient is the one most likely to sabotage my plan…no matter how I or my team makes Herculean and un reimbursed efforts to “engage” them in their OWN care…).

    I used to shake my head when satisfaction scores were shared at our clinic meetings. The weakest physicians (who I wouldn’t send my arch enemy to…and we all know those doctors) had the highest scores…

    What a meaningless carrot we chase…

    And it unfortunately disincentivizes and demoralizes those who slave over the details to make sure they miss nothing…listen a little longer…and ALWAYS deliver excellent care…

    Which should be “satisfactory” to those who know better.

    Shame on you.

  2. The protein diet types use a wrist measurement for ideal body weight. Which kind of makes sense since according to BMI most American football players are obese and need to diet.

  3. I am a cancer survivor. The tumor type was rare and aggressive. What helped my treatment to be successful was that even at age 61, I am athletic, able to ride a bike for 2 hours at over 800 calories/hr. burn rate. As such, I am over the “allowable” BMI for my height. The fact that my pulse was in the mid 50’s during treatment did not seem to matter. The doctor was apologetic but he was told that he had to inform me that I had a “high” BMI. Just because it easy to compute does not make BMI useful.

  4. BMI *might* make sense if it was actually being measured. As in, dunk tank to measure volume vs scale to measure weight. Even then, you need to take skeletal structure into account.

    Height vs weight? Without even the fine/normal/heavy bone structure columns the charts from the 60’s used? Totally useless.

    And ‘satisfaction’ measures perceived empathy much more than quality of care, so never substitutes for quality unless you truly want to measure ‘quality of empathy’.

  5. I am a layman, but I can add a bit of fuel to the BMI fire
    “More recent studies show that people considered “overweight” using the BMI measurement are healthier than those who are at the lower end of the “normal” measurement.”
    Actually, the CDC used to have higher limits. Then W.H.O. published a report of its own. Among others, both the US and Japan, according to that report, should be altered down by 5 points. The politicians in both countries forced their Government medical agencies to adopt the WHO figures, meaning in the US some 30 million people were suddenly moved to overweight or obese.

    In the US, the CDC did what the pols said. In Japan, doctors raised such a stink the POLITICCIANS were forced to retreat.

    And Japan is at least a fairly homogenous grouping, which the US certainly is not.

    I sometimes wonder about taking the BMI of long-term prisoners at Buchenwald and declaring the average as “normal” for the area…

  6. Pingback: Linky Friday #105 | Ordinary Times

  7. Think Zebras on

    Normally I would agree that a BMI isn’t a great measurement, but there are times it can be useful especially when there is suspicious treatment from care providers. Someone who had an ideal weight was put into a facility (deemed incompetent by the courts) and in less than a year doubled their body weight and no longer exercised. The weight increase was at first dismissed by doctors because of the state being involved because of the recent research that the body mass index was inaccurate, as brought out above. The family was able to use not just the weight increase but the drastic BMI change to get someone to dig deeper into the situation. I don’t know how things turned out, but sometimes it can be used for good.

Leave A Reply