EOSS, which stands for Edmonton Obesity Staging System, can help doctors more accurately predict an obese or overweight individual’s risk of death, researchers from the University of Alberta reported in CMAJ (Canadian Medical Association Journal.

Although not completely accurate, the most common tool today for measuring excess body fat is BMI (body mass index). However, BMI does not distinguish between fat and lean tissue. Neither does BMI assess for several conditions which may be linked to overweight.

According to prior studies, there is an association between high BMI and health issues related to obesity, including morbidity.

A larger waist is also linked to a higher risk of metabolic syndrome and cardiovascular disease.

EOSS was initially put forward by Dr. Arya Sharma. EOSS places obese/overweight people on a five-point scale, with 5 predicting the worst outcomes. The numbers on the scale depend on which and how many underlying conditions the overweight/obese individual has, as well as some other risk factors.

The researchers used EOSS to predict death using information from NHANES (National Health and Human Nutrition Examination Surveys), involving 8,143 individuals from 1988 to 1994, and 1999 to 2004.

According to the EOSS, 77% of the overweight/obese individuals in the 1988-1994 and 90% in the 1999-2004 periods were classified as a stage 1 or 2. It was confirmed that the risk of death for those with an EOSS score of 1 or 2 was significantly lower than those classed as stage 3.

Dr. Raj Padwal and co-authors wrote:

“Within a nationally representative cohort, higher Edmonton obesity staging system scores were a strong predictor of increasing mortality in both the overall population and in a cohort of people eligible for bariatric surgery. ..independent of BMI and the presence of metabolic syndrome or hypertriglyceridemic waist. Even within strata of BMI categories, there was clear separation of survival curves according to Edmonton obesity staging system scores.”

The researchers say that EOSS could be used for selecting patients for bariatric surgery, or other obesity treatments.

The authors wrote:

“Such enhanced risk assessment may enable a greater understanding of obesity-related prognosis and may also assist in determining the urgency of intervention.

(conclusion) We propose that [the Edmonton Obesity Staging System] be considered adjunctive to current anthropometric classification systems in assessing obesity-related risk, determining prognosis and guiding treatment.”

Written by Christian Nordqvist