What are clinical practice guidelines?

Ideally, clinical guidelines should be developed systematically – in other words, following a certain procedure:

• First a guideline committee is formed, including specialists to cover all the important aspects of the medical condition in question. The committee is usually led by a member of the medical association responsible for the medical condition.
• It collects as much information as possible from different sources and assesses the information based on predetermined criteria. The various assessments and opinions of the committee members are discussed and taken into consideration when writing the guidelines. In other words, the recommendations are "consensus-based."
• The committee members have to declare any conflicts of interest. For instance, they have to say whether they have worked for a pharmaceutical company that makes medication to treat the medical condition that the clinical guidelines are being written about.

Good clinical guidelines should be based on up-to-date scientific knowledge, and it should be possible to follow the recommendations in daily medical practice. International uniform standards are now used worldwide for the assessment of clinical guidelines. In Germany, the Association of the Scientific Medical Societies (Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften, or AWMF) coordinates the development of clinical guidelines. It divides guidelines into four categories:

• S1 guidelines: These guidelines summarize the recommendations of experts. They do not systematically compile and assess the medical knowledge in the area in question. So the recommendations made in S1 guidelines aren’t very reliable.
• S2K guidelines: S2K guidelines are developed by a committee of specialists in the medical field in question. The recommendations made are consensus-based. Because medical information isn’t systematically collected and assessed here either, the information that the recommendations are based on isn’t very reliable.
• S2e guidelines: Here the guideline committee systematically compiles the medical knowledge from different sources. But if the members of the committee disagree, they do not use a consensus-based approach to develop the guidelines.
• S3 guidelines: This is the only category of guidelines that meets all of the following requirements: The guideline committee includes experts representing various areas of the field in question, and the medical knowledge is systematically collected and assessed. What’s more, if different members of the committee have different views, a specific procedure is followed in order to develop consensus-based recommendations.
  S3 guidelines are the most reliable kind of guidelines, but they also involve the most effort: It can take several years to develop them. When S3 guidelines are developed for doctors and health care professionals, patient guidelines are usually developed too.