Conclusions from surveys may not consider important biases: a systematic survey of surveys

OBJECTIVES: Surveys can inform important health care questions. However, should decision-makers believe strong conclusions that authors of surveys report? Objectives of this systematic survey of surveys are to describe the characteristics and conduct of surveys and investigate the association of the conduct with the conclusions. STUDY DESIGN AND SETTING: We randomly selected 180 surveys published over 1 year in core clinical journals that …