Edmonton Obesity Staging System (EOSS) Predicts Use of Health Services and Pharmacotherapies in Australian Adults

The Edmonton Obesity Staging System (EOSS), which classifies obesity based on the presence of medical, mental, and functional impairments using a 5-point ordinal scale, is now increasingly used in the clinical assessment of individuals presenting with obesity.

We have previously shown that EOSS, which is largely independent of BMI, is a far better predictor of mortality than BMI, waist circumference, or the presence of metabolic syndrome (Padwal et al, CMAJ 2011).

Now, a cross-sectional analysis of data from the Australian Health Survey by Evan Atlantis and colleagues, published in Clinical Obesity, shows that EOSS is also significantly better than BMI for predicting polypharmacy and health service use.

The researchers examined data in a subgroup of individuals from the nationally representative sample of participants in the 2011-2013 Australian Health Survey for whom physical measurements of BMI and waist circumference were available (n = 9730).

Overall, the number of primary care physician and specialist consultations, encounters with allied health care, number of pharmacotherapies and hospitalisations increased by EOSS stages.

In contrast, BMI was a significantly better predictor of having discussed reaching a healthy weight, increasing physical activity, and eating healthy food with their primary care physician in the last 12 months than the EOSS.

Overall, the results are not surprising. EOSS is a measure of health rather than size, which readily explains why individuals in higher EOSS categories, who are sicker, also experience greater healthcare needs.

Although EOSS (by definition) identifies sicker individuals living with obesity, importantly, the data also shows that doctors’ advice to improve health behaviours is largely driven by patient size (BMI). It thus appears, that larger patients are more likely to receive advice on weight management, healthy eating or physical activity, irrespective of their actual health status.

With regard to hospital use, the authors note:

“Since hospitals account for the majority of health spending,31 preventing patients from progression through the higher EOSS stages should be a high priority in health policy and a key clinical objective rather than weight loss. For instance, there is likely to be a greater reduction in health costs if an individual at a lower BMI with higher complications status (EOSS stages 3 and 4) has early access to effective medical and surgical management of obesity than another at a higher BMI with no or few health impairments (EOSS stages 0‐2). Thus, health policy and clinical guidelines about access to clinical obesity services or intensity of treatments based on BMI alone will likely miss a considerable proportion of individuals who may well benefit from clinical obesity care. It could also lead to overtreatment in low‐risk individuals with high BMIs and under treatment of high‐risk individuals with lower BMIs.”

Clearly, wider use of EOSS in clinical practice and health services planning has the potential to better target obesity interventions to those individuals who stand to benefit the most,

Edmonton, AB