Latest Drugwonks' Blog
Top 10 Reasons Why The BMI Is Bogus
by KEITH DEVLIN
The BMI Formula
BMI = weight in pounds/(height in inches x height in inches) x 703
The 703 is to convert the index from the original metric version of the formula.
CDC Recommendations:
Below 18.5 = Underweight
18.5 to 24.9 = Ideal
25.0 to 29.9 = Overweight
30.0 and above = Obese
text size A A A July 4, 2009
Americans keep putting on the pounds — at least according to a report released this week from the Trust for America's Health. The study found that nearly two-thirds of states now have adult obesity rates above 25 percent.
But you may want to take those findings — and your next meal — with a grain of salt, because they're based on a calculation called the body mass index, or BMI.
As the Weekend Edition math guy, I spoke to Scott Simon and told him the body mass index fails on 10 grounds:
1. The person who dreamed up the BMI said explicitly that it could not and should not be used to indicate the level of fatness in an individual.
The BMI was introduced in the early 19th century by a Belgian named Lambert Adolphe Jacques Quetelet. He was a mathematician, not a physician. He produced the formula to give a quick and easy way to measure the degree of obesity of the general population to assist the government in allocating resources. In other words, it is a 200-year-old hack.
2. It is scientifically nonsensical.
There is no physiological reason to square a person's height (Quetelet had to square the height to get a formula that matched the overall data. If you can't fix the data, rig the formula!). Moreover, it ignores waist size, which is a clear indicator of obesity level.
3. It is physiologically wrong.
It makes no allowance for the relative proportions of bone, muscle and fat in the body. But bone is denser than muscle and twice as dense as fat, so a person with strong bones, good muscle tone and low fat will have a high BMI. Thus, athletes and fit, health-conscious movie stars who work out a lot tend to find themselves classified as overweight or even obese.
4. It gets the logic wrong.
The CDC says on its Web site that "the BMI is a reliable indicator of body fatness for people." This is a fundamental error of logic. For example, if I tell you my birthday present is a bicycle, you can conclude that my present has wheels. That's correct logic. But it does not work the other way round. If I tell you my birthday present has wheels, you cannot conclude I got a bicycle. I could have received a car. Because of how Quetelet came up with it, if a person is fat or obese, he or she will have a high BMI. But as with my birthday present, it doesn't work the other way round. A high BMI does not mean an individual is even overweight, let alone obese. It could mean the person is fit and healthy, with very little fat.
5. It's bad statistics.
Because the majority of people today (and in Quetelet's time) lead fairly sedentary lives and are not particularly active, the formula tacitly assumes low muscle mass and high relative fat content. It applies moderately well when applied to such people because it was formulated by focusing on them. But it gives exactly the wrong answer for a large and significant section of the population, namely the lean, fit and healthy. Quetelet is also the person who came up with the idea of "the average man." That's a useful concept, but if you try to apply it to any one person, you come up with the absurdity of a person with 2.4 children. Averages measure entire populations and often don't apply to individuals.
6. It is lying by scientific authority.
Because the BMI is a single number between 1 and 100 (like a percentage) that comes from a mathematical formula, it carries an air of scientific authority. But it is mathematical snake oil.
7. It suggests there are distinct categories of underweight, ideal, overweight and obese, with sharp boundaries that hinge on a decimal place.
That's total nonsense.
8. It makes the more cynical members of society suspect that the medical insurance industry lobbies for the continued use of the BMI to keep their profits high.
Insurance companies sometimes charge higher premiums for people with a high BMI. Among such people are all those fit individuals with good bone and muscle and little fat, who will live long, healthy lives during which they will have to pay those greater premiums.
9. Continued reliance on the BMI means doctors don't feel the need to use one of the more scientifically sound methods that are available to measure obesity levels.
Those alternatives cost a little bit more, but they give far more reliable results.
10. It embarrasses the U.S.
It is embarrassing for one of the most scientifically, technologically and medicinally advanced nations in the world to base advice on how to prevent one of the leading causes of poor health and premature death (obesity) on a 200-year-old numerical hack developed by a mathematician who was not even an expert in what little was known about the human body back then.
You would think (if you accept the stereotype) that trial lawyers would warn against the proposal as well. But Greg Webb, a blogger for the Injury Board Blog Network has penned a measured and thoughtful piece on the FDA's safe use proposal for expanded OTC access..
"Representatives of the American Medical Association (AMA) and the American College of Allergy, Asthma and Immunology (ACAAI) have gone on record objecting to the proposed new safe-use class of medications. Roland Goertz, MD, president of the American Academy of Family Physicians (AAFP), stated that the safe-use designation where pharmacists dispensed medications without a patient having to see a doctor first, “could seriously compromise the physician's ability to coordinate the care of multiple problems of many patients.”[1]
Health insurers reportedly have tentatively "approved" of the measure. Without proper safeguards, there is some concern that patients may obtain drugs that they may not need. The insurers also would have to determine how to cover drugs that fell into this category. Additionally, the health insurers were in favor of "expanding access" to helpful medications.
Because pharmacists are more easily accessible than physicians who require appointments for frequently costly office visits, the FDA believes that the “safe-use” designation may benefit many Americans who presently go untreated with legitimate medical needs. Doubtless the collection of comments and the promulgation of a new regulation on safe-use medicines by FDA (requiring additional debate) will cause more lines to be drawn in the sand of looming health issues. Is this the wave of the future for certain medications? Much of it makes sense, and ultimately would save money by preventing potentially unnecessary doctors' visits. What are the unintended consequences?"
Mr. Webb's article is well worth reading because it lays out the FDA proposal clearly. It is also noteworthy because it shows that the AMA and other groups are more hysterical about the Rx-OTC issue than the trial bar.
The FDA has proposed a benefit-risk assessment system for weight loss devices that would use available safety data for a device to set efficacy thresholds for a pivotal trial of that device. BioCentury reports that the proposal came in briefing documents issued to FDA's Gastroenterology and Urology Devices Panel ahead of a meeting on Thursday and Friday to discuss issues in the development of devices placed endoscopically or laparoscopically.
Devices would be classified into one of three risk levels based on the percent of patients who experience mild, intermediate and severe adverse events over one year. For example, to qualify for the lowest risk category, devices can have high rates of the most mild events (up to 100%), low rates of events of intermediate severity (2-5%), and very low rates of the more severe events (<0.1%).
Each level of risk would set corresponding efficacy endpoint targets for pivotal trials. Targets for the least risky devices would be based on endpoints used for weight loss drugs, while targets for the highest risk devices would be based on the two FDA-approved obesity devices, which the agency said fall into the high risk category. Those are the Lap-Band adjustable gastric banding system from Allergan and the Realize adjustable gastric band from the Ethicon Endo-Surgery.
FDA also proposed that efficacy be measured using percent total body weight loss instead of the current standard of percent excess weight loss. The panel is part of the Medical Devices Advisory Committee.
Yesterday the U.S. House Energy and Commerce Committee's health subcommittee voted unanimously to pass the PDUFA reauthorization bill. A full committee vote on the draft is expected Thursday and a full House vote is expected later this month.
Medscape Medical News
Pharmacists Dispensing Without Rx 'Scary,' Say Med Societies
Robert Lowes
May 2, 2012 — Imagine a patient walking into a pharmacy, self-diagnosing a cough at a kiosk with medical software, and then getting a drug from a pharmacist in the back of the store, all without a physician's prescription.
The US Food and Drug Administration (FDA) is imagining this scenario, much to the alarm of the American Medical Association (AMA) and other medical societies, which see the beginnings of an end-run around physician authority.
Sandra Fryhofer, MD, chair-elect of the AMA Council on Science and Public Health, said her group continues to "strongly support" the status quo of 2 drug classes — prescription and traditional OTC. In exploring how new technologies and new roles for pharmacists might expand the portfolio of OTC drugs, the FDA should not "undermine the relationship that a patient has with his or her physician."
"In our view, lack of oversight from a practitioner could be a serious concern," said Dr. Fryhofer.
The FDA has not provided any evidence showing that patients with hypertension, hyperlipidemia, or asthma can diagnose and manage these conditions by themselves, she noted. "The balance of medical evidence strongly suggests otherwise." She also estimated that patients would pay more out-of-pocket for drugs that insurers would shift into the OTC safe-use category.
Bobby Lanier, MD, speaking for the American College of Allergy, Asthma and Immunology (ACAAI), raised similar concerns, but more pointedly.
"The new proposals here being discussed are chilling and scary," said Dr. Lanier. "You are facilitating bad behavior by not having (patients) talk to a clinician. In our mind, there is no substitute for a clinician."
Which brings to mind the fact that when the FDA decided to move painkillers and allergy meds OTC, you heard the same dire warnings. Now the same groups are seeking to change an Obamacare law requiring a doctor's prescription for OTC drugs purchased through a Flexible Spending Account. Not necessary and too much of a hassle according to the AMA and other medical lobbies. In Dr. Lanier's words, it's ok to facilitate bad behavior with existing OTC products but not new ones.
The FDA should be commended for promoting more consumer-driven care. As Peter and I demonstrated in our recent survey on cough medicine usage, the vast majority of Americans like OTC access because it makes health care simpler and therefore more likely. Doctors are behind the curve on the consumer revolution. Rather than trying to derail it, doctors should embrace new ways of connecting with patients and finding ways to help consumers help themselves. http://cmpi.org/uploads/File/CMPI_CoughSurvey_KeyFindings.pdf
BioCentuty reports:
House moves closer to Senate on PDUFA
The U.S. House Energy and Commerce Committee posted a new draft PDUFA reauthorization bill that is more closely aligned with the Senate PDUFA bill than previous versions. Changes that reflect the Senate bill include dropping sections that would add jobs creation and economic development language to FDA's mission and adding a section that would create an expedited development pathway for breakthrough drugs.
However, several items in the House draft bill are still not in the pending Senate version, including provisions to increase public participation in crafting guidance documents and creation of a new priority review voucher system to encourage development of therapies for rare pediatric cancers. The House draft also requires that FDA provide Congress a 60-day notice prior to issuing guidance on the regulation of laboratory-developed tests. The Energy and Commerce Committee's health subcommittee is scheduled to meet Tuesday (today) to deliberate on the draft bill.
Per today’s Washington Times, “Health insurers gave a tentative thumbs-up Monday to the Food and Drug Administration’s proposal to make drugs treating chronic conditions available without a prescription by classifying them in an all-new category.”
Insurance companies cautiously support the idea but warned Monday in a letter to the FDA that a host of complications could arise.
Without the right safeguards in place, patients could obtain drugs they don’t need and it’s unclear who would be held liable if they do, said Robert Zirkelbach, spokesman for America’s Health Insurance Plans.
Insurance companies also would have to figure out whether and how they would cover drugs that fall into the new category.
“Expanding access is something that we support, but these other issues would have to be addressed for this to work if they decide to move forward with that,” Mr. Zirkelbach said in an interview.
If the FDA decides to move ahead with the plan, it would create a third category for classifying drugs.
Called “safe use” drugs, patients wouldn’t need a prescription but neither could they obtain them over the counter. Instead, people could only buy the drugs after diagnosing their ailments online or in the pharmacy.
Seeking a way to expand access to drugs for Americans who struggle with common conditions such as high cholesterol, migraines and diabetes, the FDA has raised the idea several times over the past decade and brought it up again in March, asking the public to weigh in.
It’s uncertain whether the agency will sign off on the new policy since the idea has faltered in the past under opposition by doctors and other medical providers. The American Medical Association has said it could open the door to drug misuse and expects that out-of-pocket costs will rise for patients.
When it comes to addressing and solving the drug shortages, what are the most important variables to consider?
According to Healthcare Intermediaries: Competition and Healthcare Policy at Loggerheads? -- a new white paper by the American Antitrust Institute, a key question “is whether high levels of consolidation in intermediary markets and potentially exclusionary conduct have caused or exacerbated shortages.”
“One major protection against shortages is a stable supply chain, which is largely determined by the number and diversity of suppliers. The concept of supply chain “fragility” is increasingly relevant in operations research, marketing, economics, and even sociology. Supply chains featuring only a few competitors and high entry barriers at critical junctures are excessively exposed to the risk of disruption and collapse following an exogenous shock … but a fragile supply chain can also be inefficient when it “fails” because of excessive consolidation that leaves few suppliers.”
Intermediary conduct can, “threaten to impair the achievement of healthcare policy goals such as affordable healthcare, choice in medical products, a stable supply chain, and diversity of supply.”
The paper points out that sterile injectables. In 2010, 60 percent of sterile injectables (which accounted for 80 percent of the drugs in shortage) were sole-sourced. Markets for specific drugs are likely to be even more concentrated because only one or two firms produce them. Markets for generic drugs – which accounted for 60 percent of sterile injectables and 50 percent of all shortages – are also concentrated. In 2010, the top three firms accounted for about 70 percent of the generic sterile injectable market and 90 percent of the generic sterile injectable oncology segment of the market.
Indeed, the FDA notes that while demand in the generic and oncology segment of the market is robust, the supply system is “vulnerable to drug shortages because a large supply disruption is difficult to make up with alternative suppliers.” This is compounded by low demand and supply elasticities for certain drugs, stringent product manufacturing quality controls, dedicated production lines, and “just-in-time” manufacturing and inventorying practices.
Among other suggested next steps, the paper recommends that regulatory initiatives designed to address drug shortages “should focus less on reporting requirements and more on the analysis of competition in intermediary markets and upstream markets for drugs, and medical devices and supplies.”
A paper worth reading with conclusions worth debating.
" The division shall have the power to design and to revise, consistent with this chapter, a basic schedule of health care services that enrollees in any health insurance program implemented by the division shall be eligible to receive. Such covered services shall include those which typically are included in employer-sponsored health benefit plans in the commonwealth. The division may promulgate schedules of covered health care services which differ from the basic schedule and which apply to specific classes of enrollees. The division may promulgate a schedule of premium contributions, co-payments, co-insurance, and deductibles for said programs, including reduced premiums based on a sliding fee, and other fees and revise them from time to time, subject to the approval of the division of insurance; and provided, however, that such schedule shall provide for such enrollees to pay one hundred per cent of such premium contributions if their income substantially exceeds the non-farm poverty guidelines of the United States office of management and budget."
Compared to this bill, Obamacare is free market reform.
But is this decline really due to the FDA’s ability to demand earlier information about potential shortages from manufacturers?
“I am both amazed and delighted to see the progress that’s been made, said Hamburg. Key word: “Amazed.”
While the FDA’s new authorities are both timely and important, there are many pieces to the drug shortages problem – not the least of which is that (when it comes to hospital injectables) 30% of manufacturing capacity is off-line due to FDA inspection issues. That’s a lot of capacity. In fact, according to the agency, 43% of reported potential shortages were due to manufacturing issues.
Greater cooperation between agency and manufacturers is required so that this gap can be corrected before problems arise. A 30% hole in manufacturing is more than a hint that something’s amiss on both sides.
Is it a victory when you are solving the problems you create?
Center for Medicine in the Public Interest is a nonprofit, non-partisan organization promoting innovative solutions that advance medical progress, reduce health disparities, extend life and make health care more affordable, preventive and patient-centered. CMPI also provides the public, policymakers and the media a reliable source of independent scientific analysis on issues ranging from personalized medicine, food and drug safety, health care reform and comparative effectiveness.
