TU, Germany
These terms may be used as synonyms in many situations, specially by non-native English-speakers. In some languages, the translation for guideline, guidance and protocol may refer to the concept of Clinical Practice Guidelines and thus be completely interchangeable. However, the terms may have slightly different meanings specially concerning the degree of legal-binding. In some countries a guideline has to be followed, otherwise some kind of sanctions may be the consequence (i.e. not reimbursement of a procedure). Guidance can be interpreted as “orientation”, i.e. as something which can or should be followed, but without any sanctioning enforcement (i.e. it is not legally binding). Protocol can be understood as a road map on how to act in front of a specific clinical situation (e.g. fever of unknown origin, weight loss). Protocols are often illustrated with a flow chart, in which the different steps as well as the decision-nodes are shown. In some countries/ contexts protocols my refer to local (e.g. hospital or primary health care centre) action plans which should be followed when a clinical problem presents.
Advice can be translated as recommendation or orientation. Thus it can be considered to have no legal-binding character. In contrast to guidance – which may refer more to providers or clinical decision-making – advice refers more to decision-making at the macro- or meso-level.