IQWiG provides an overview of the standard of care in the treatment of obesity

As in all industrial countries, the number of obese people is also increasing in Germany, in all social classes and age groups. Obesity (or adiposity) is associated with several health problems. For example, obese people more often suffer from certain diseases, such as type 2 diabetes mellitus or high blood pressure. The Federal Joint Committee (G-BA) is therefore developing a module on obesity that is to supplement the existing disease management programme (DMP). DMPs are structured treatment programmes for chronically ill patients, and designed to enable optimum treatment in a structured fashion according to the latest scientific evidence.

The Federal Joint Committee commissioned the Institute for Quality and Efficiency in Health Care (IQWiG) to extract those recommendations from evidence-based clinical practice guidelines (CPGs) that could be relevant to the DMP module planned. On 3 April 2009 the Institute published its findings in the form of a final report.

IQWiG did not perform its own evaluation of the evidence

Together with its external experts, IQWiG systematically searched for evidence-based CPGs on obesity. In a first step the methodological quality of the CPGs was evaluated. The recommendations included were then extracted and it was reviewed to what extent - according to the statements in the CPGs - these recommendations were based on high-quality studies. A total of 10 CPGs were included. However, the evidence on which the individual recommendations were based was not assessed. This is where CPG appraisals differ from the Institute's benefit assessments of drug and non-drug interventions.

Recommendations on losing weight are relatively well supported by studies

Overall, IQWiG was able to identify a comparatively large number of evidence-based recommendations on losing weight. In contrast, the situation was different for the following aspects of care: classification of weight, monitoring of patients, long-term weight stabilization, quality indicators, and coordination of care. According to the CPGs, only a few recommendations based on high-quality studies are available.

For weight classification, the CPGs recommend calculating the body mass index (BMI). The BMI is a measure that describes the relation between weight and height (in kg/m²). People with a BMI between 25 and 30 are categorized as "overweight”, and as "obese” if they have a BMI of over 30. According to the CPGs, in addition to calculating the BMI, the waist circumference should be measured and a detailed medical history taken.

To achieve weight loss, a reduction in calorie intake, physical activity, and behavioural therapy are seen as first-line treatments; ideally they should be combined. To support these treatments, specific medications can be used in rare cases, for example, if patients have a BMI of over 30 kg/m². A surgical intervention should usually only be considered in patients with a BMI of over 40 kg/m². Certain diseases make it necessary for people who are only mildly overweight to lose weight.

Procedure of report production

The preliminary results (preliminary report) were published by IQWiG at the end of July 2008 and interested persons and parties invited to submit comments. After the conclusion of the commenting procedure, the preliminary report was revised and the final report sent to the contracting agency, the Federal Joint Committee, at the beginning of February 2009. The documentation of the written comments, as well as meeting minutes of the oral scientific debate, will be published in a separate document simultaneously with the final report.

Contact: Tel +49(0)221-35685-0, info@iqwig.de