Oregon health officials are looking at some fundamental changes to the state’s health care system.
And one of their goals is to figure out a way to measure how the changes are working -- and to grade success.
But which statistics will provide the best measuring stick? Just choosing the right statistic is a complex process.
To show how complex it can be, Kristian Foden-Vencil focused on one measurement under consideration -- the body mass index. He found it has its pros and cons.
At a Kaiser Permanente health clinic in Northeast Portland, medical assistant Camelia Hale calls her next patient, "Lavone Heaster?"
Lavone Heaster stands up to walk into the doctor's office. Hale's first job is to weigh her and measure her height. Those measurements will help her find Heaster's body mass index.
It's a simple calculation that will result in a score for Heaster’s BMI. A score that falls below 20 would suggest she's underweight. Higher than 25 and she would be considered overweight.
But there's a problem.
"I decline to be weighed," Heaster says.
Heaster's had Type One diabetes since she was nine, and feels the BMI is a simplistic and misleading figure.
"First of all I think it intimidates people when they go to the doctors and they have to be weighed. And I personally am intimidated. And then secondly, I think when you use it for body mass index, you do a simple calculation on body mass index and you don't take into account of how much activity and how muscles are working and there are much more expensive ways that you can actually get a better body mass index reading," according to Heaster.
Heaster is not alone. Nurse Melinda Williams says over the years her patients have taken all kinds of steps to get a low reading on the scale. Some take their shoes off, or their belt or even their jewelry.
"And I've had a patient I actually took into a room and put a gown on. And she wanted to come back out. Some are pretty pleasant. Some are a little irate. Some want you to take it again after they've gone to the bathroom. That does happen," she said.
Genevieve Gage doesn't do that, but she also has issues with the BMI. She's a medical assistant at Kaiser. She’s battled her weight all her life. She recently lost 88 pounds. But she says, she's disappointed at her BMI score.
"Even though I'm down to a size 13 -- 14, down from 24. I'm still technically obese and I don't know that I agree with that assessment just based on how much muscle I have because I have a lot of muscle. I've been doing a lot of body building and stuff like that and I believe muscle weighs more than fat so I've had some questions actually about the index myself."
She's right. The index does have some problems. An extremely healthy athlete may be considered overweight, because the index assumes his or her extra muscle mass is actually fat.
Dr. Keith Bachman with Kaiser Permanente is an expert on body mass index. He says athletes aren’t the only ones whose BMI scores may be misleading. Growing kids also need a completely different body mass index.
"You actually do need the sex of the child and you do need their exact age. Because it's normal to have periods of growth where there is higher body fatness and lower body fatness in children," he said.
He says older people also tend to have lower body mass indexes. And he says there are other exceptions.
That said, Dr. Bachman believes the BMI is a good general gauge of health.
"I think measuring BMI is a marker for a good healthcare system. That's one of the basic vital signs that in this day an age, with all the obesity and complications of obesity out there. Measuring BMI as a marker of good healthcare, just like measuring blood pressure seems very appropriate to me," Bachman explained.
The body mass index calculation is thought to have been developed in the early 1800s by a Belgian scientist. He wanted a quick way to measure large numbers of people -- so populations could be mathematically compared.
Then, in the 1970's, the University of Minnesota used the calculation to assess the health risks of 7,000 men. It found the body mass index to be a fairly good measurement of people's health.
Doctor Tom Syltebo sits on a panel that's looking into what performance measures Oregon should use to grade its new health care system.
"There's no question from a population standpoint, if people are significantly overweight, that has health implications. And yet there's the rare person whose weight is high because they're professional athletes. But in general, for a population, BMI matters," Syltebo said.
He says if a health care system can show its patients are losing weight, then it is showing that they're generally becoming healthier.
Other experts have their doubts.
Thomas Yackel is the chief health information officer at Oregon Health and Science University.
"If you grade physicians based on a characteristic of their patients, guess what, they're going to cherry pick their patients to look good. Right, you design the system to reward them to have patients who have a low BMI, guess what's going to happen. They're going to, they're not going to seek out patients who really need the treatment. So you've got to be really careful about how you design and choose your quality metrics so that you get the outcome that you want," Yackel said.
And the BMI is just one statistic. The state is looking at many ways to grade its new health care system. It's also looking at gauging how many patients are readmitted to hospital with the same problem; how happy patients are with the care they receive; and whether regular blood sugar checks can prevent illness.
Tina Edlund of the Oregon Health Authority thinks by looking at several different criteria, any problem with an individual measure -- like the body mass index -- can be diluted.
"I think that when you look at a whole population, a lot of those issues wash out."
Edlund has a list of a couple of dozen grading ideas. A panel of 130 health experts is expected to pick the key measurements from that list.
At this point, Edlund expects some form of the body mass index will be used. But what she doesn't know is how the grades might be used. For example, will a health care system get more money if it gets good grades?
"There's a lot of approaches. But yeah, there'll be financial incentives. How they work is the question."
Once health experts have whittled down the list of possible measurements, they’ll send on their recommendations to the legislature for a final decision.
On the Web
Consumer Reports: BMI Calculator
NHI BMI Calculator:
CDC BMI Calculator:
NPR: Keith Devlin: Top 10 Reasons Why The BMI Is Bogus
This story is part of a project on health care in the states, a partnership of OPB, NPR and Kaiser Health News.
Kaiser Health News is a nonprofit news service covering health policy and politics. It is an editorially-independent program of the Kaiser Family Foundation, which is not affiliated with Kaiser Permanente.