Is it time to abandon BMI?

This article originally appeared at Healthcare Dive on Feb. 15, 2016.

A recent UCLA study concluded nearly 75 million U.S. adults are being misclassified as healthy or unhealthy based on Body Mass Index (BMI) and argued healthcare and health insurance entities should strictly utilize “actual health markers.” This comes after the U.S. Equal Employment Opportunity Commission recently proposed rules that would let employers penalize their staff for as much as 30% of their health insurance costs if they don’t satisfy 24 health criteria, including BMI.

The question now is whether the study will nudge wellness programs, payers and providers toward abandoning BMI as a health measure, and what that would mean for the healthcare industry.

While on the one hand, it seems stakeholders should be interested in improving the accuracy of their patient data, cost estimates, employee charges, etc., some may find it disruptive to move to other health measures and resist.

A brief history behind the measurement

The measure, which is calculated by dividing a person’s weight in kilograms by the square of their height in meters, was invented in the 1800s as a way to gauge obesity in the general population but was not intended to measure individuals, critics argue. They say in large groups the errors tend to cancel out but when applied to individuals, it’s hit or miss because it does nothing to distinguish between bone, muscle and fat. So while the measure tends to correlate with obesity in many otherwise very average people, it fails for many others—most notably those who are particularly muscular, such as athletes, or those who have lost muscle, such as the elderly.

At least one cynic suggests the inaccuracy is part of the appeal, as it benefits employers to target healthy individuals alongside the unhealthy for higher payments or penalties.

A question of legality

Attorney David M. Kaufman, a Partner in the Healthcare Practice Group at Freeborn & Peters LLP and the former General Counsel of Blue Cross & Blue Shield of Illinois, tells Healthcare Dive programs that continue to reply on BMI could ultimately face legal challenges.

He notes the purpose of a wellness program is to improve the health of employees and to reduce healthcare costs, and that federal regulations require they be reasonably designed to promote health and prevent disease.

“A program relying on an inappropriate metric would not meet the standards for such a program and could subject the program or the regulation to legal challenge,” Kaufman says. “Healthcare entities generally support the practice of evidence-based medicine and to the extent that BMI is determined to be an inappropriate metric by which to measure health, relying on BMI would not support the goals of a wellness program.”

What are the alternatives?

Given that BMI is simple and familiar, and therefore well-entrenched, its elimination could indeed cause some disruption and require revisions. “However, BMI would not be the first measure of health considered to be valid only to be discredited later,” Kaufman adds.

Hembroff argues modern technology and 3D scanning capabilities make Body Volume Index (BVI) a more accurate and complete alternative, and it can be done with relatively inexpensive devices such as the Microsoft Kinect. “BVI can look at an individual’s body and weigh fat distribution in problematic areas such as abdominal volume to gain a more accurate assessment of a person’s health. Although not perfect, BVI is a more accurate measurement than BMI,” he says.

Sonic Boom Wellness CEO Danna Korn is also a vocal proponent of abandoning BMI.

“It’s about time,” she says. “It’s crazy that we’re holding onto an inaccurate measure all of these years.” Korn says Sonic Boom Wellness grudgingly uses BMI as a measure because it’s so commonly expected, but the company tries to downplay it and “put a whole lot of caveats around it.”

She suggests it can even be dangerous to use BMI because of the way it can target some who should not try to lose weight.

“There are far more accurate ways to get a measure of whether a person is overweight,” she argues. While some alternative health measures may be costly, she champions the simple waist to hip ratio. “It’s not expensive to do it, we can implement it relatively easily, and it’s far more accurate than a BMI,” she says.

She suggests it will take time to see change, noting authorities including the NIH and CDC still legitimatize the use of BMI, though they do acknowledge its limitations. Any entities that want to hold onto BMI may be able to point to such leading authorities until any sweeping new guidelines are made.

“I think what you’re going to find is that people keenly attuned to accuracy are going to embrace this,” Korn says, “but a lot of major organizations will find it hard to change their metrics.”