A new diagnostic method developed by researchers in the Faculty of Medicine & Dentistry at the University of Alberta is proving it can be a reliable tool for health professionals to predict an overweight or obese patient’s risk of death and even the degree to which they need to lose weight.
The tool is called the Edmonton Obesity Staging System, a set of questions and criteria that help classify obese people, created by obesity expert Arya Sharma in the Department of Medicine. It is used in addition to body mass index or BMI, which is commonly used by doctors to classify overweight and obese patients. While BMI is simply calculated from a patient’s height and weight, this new system asks important questions about the state of health of the patient including medical, mental and functional problems related to their excess weight.
“Within each level of BMI you can have patients who have no obesity-related health problems at all or people who have a lot of obesity-related health problems,” said Sharma. “If you’re going to make medical decisions about who needs treatment and how much treatment somebody needs—just answering the question about whether this patient even needs to lose weight—knowing how big someone is isn’t actually that helpful.”
Sharma and colleague Raj Padwal, also from the U of A, published two papers this week. In one, published in the Canadian Medical Association Journal, the pair looked at a large representative sample of the United States population, which showed that higher EOSS scores were a strong predictor of increased mortality in both the overall population and a subset of individuals considered eligible for bariatric surgery—independent of their BMI, waist circumference or the presence of metabolic syndrome. The study also shows that BMI alone doesn’t help predict who will live longer.
“This tool puts an emphasis on individualized treatment needs, depending on how sick or at-risk a patient is,” says Sharma. “Because obesity requires long-term treatment and can be costly, knowing which patients need to be most urgently treated to improve their health and which do not, can save health-care dollars.”
Additionally, in a paper also released on Aug. 15 in the journal Applied Physiology, Nutrition and Metabolism, these researchers, along with investigators from York University in Toronto, categorized 6,000 obese Americans according to EOSS criteria. They compared their mortality risk to 23,000 lean individuals over a 16-year span and found that obese individuals with a low EOSS score were found to have the same mortality risk as lean individuals, and were less likely to die from cardiovascular causes.
“We were pleased to see our results were quite robust in the sense that we have two studies that show that the Edmonton Obesity Staging System predicts mortality independent of BMI,” said Padwal.
The pair’s next validation study will ask doctors how well the staging system works.
“We are now looking at the staging system in actual medical practise,” said Sharma. “We’re using it, for example, in the bariatric clinic at the Royal Alexandra Hospital and further work to see how this can best be used in clinical practice.”
