[Critical analysis of asthma guidelines: are they really evidence-based?].

Recent years have seen a growing reliance on "evidence-based" guidelines or consensus statements, in which rigorous, explicit methods are used to translate the complex findings of scientific research into operational recommendations for medical care. Various factors can affect the validity of the conclusions they express, however. The purpose of this review was to compare the levels of evidence supporting treatments for acute asthma in adults according to 3 of the most important guidelines. It seems that even though these guidelines are based on an approach that is more or less rigorous, there are considerable gaps and inconsistencies that compromise their validity. Our main sources of information should therefore be those that apply the best research designs, namely randomized controlled trials or meta-analyses of such trials with consistent results and a low probability of bias.