Can we trust strong recommendations based on low quality evidence?
Liang Yao, Gordon Guyatt, Benjamin Djulbegović
Abstract
A necessary requirement for development of trustworthy guidelines is to respect the relation between the quality (certainty) of evidence and strength of recommendations. Strong recommendations are justified when they are based on high quality evidence, because such recommendations are considered more accurate.1 On the other hand, uncertainty in benefits and harms (that is, low quality evidence) generally leads to weaker recommendations. The failure to recognise this important principle results in a tendency to issue strong recommendations based on low quality evidence (which we call discordant recommendations), often leading to harm. For instance, based on advice from low quality evidence, women have experienced avoidable adverse effects from hormone replacement therapy prescribed for the prevention of cardiovascular disease; and …