[The impact of guidelines, standards and economic restrictions on clinical decision-making processes].

Guidelines aim at improving clinical decision-making. Contrary to textbooks and reviews that want to improve medical knowledge, guidelines try to influence medical behaviour. Scientific models of clinical decision-making such as the action theory and empirical data on the effects of guidelines suggest that guidelines will not always reach their goals but can instead even lead to a deterioration in the quality of medical care. Therefore there is a need for controlled clinical trials to investigate whether guideline-exposed physicians yield better patient outcomes than guideline-naïve physicians. Guidelines should only be regarded as evidence-based if their positive effects have been empirically demonstrated.