Stark differences in the availability and access to obesity surgery across the UK will not be corrected until the measures used to determine eligibility provide a more accurate assessment of risk.
The National Institute of Health and Clinical Excellence (NIHCE) guidelines for weight loss surgery are based on Body Mass Index (BMI). To qualify for surgery, an individual must have a BMI of ≥ 35kg/m2 with complications (diabetes, hypertension etc), or a BMI of ≥40kg/m2 with or without complications. The problem is that BMI is an unreliable measure of risk at the individual level, since it provides no information about the distribution of body fat, the relative proportions of fat to lean mass, or the metabolic status of the patient.
Using BMI as a means of deciding who is eligible and who is not, can lead to absurdities, with which those of us who work in the field are all too familiar. For example, one may have a female patient with a BMI of 41 kg/m2 with minimal health problems who would be eligible for surgery, whereas the Asian male, with type II diabetes, hypertension and high cholesterol levels, but with a BMI of 34.5kg/m2, would be denied a surgical intervention. This, despite that fact that surgery would almost certainly cure is diabetes and prolong economically productive life (probably by decades), with significant cost savings to the NHS.
Factors which determine the risk of the individual and, therefore, the likely beneficial impact of a surgical weight loss procedure, include not only the presence or absence of diabetes or other factors such as high blood pressure, but ethnicity, waist measurement, genetic factors, family history etc. All need to be taken into account when identifying those who are most likely to benefit from a surgical procedure.
Obesity surgery is by far the most effective intervention for the treatment of chronic obesity and, in experienced hands, is remarkably safe. However, until the NIHCE adopts a more scientifically informed and standardised approach to the assessment of risk at the individual level, the application of scarce resources will continue to be inequitable.
Dr David Ashton, MD PhD
Medical Director, Healthier Weight
