Several reasons explained the variation in the results of 22 meta-analyses addressing the same question

OBJECTIVE: The objective of this study was to assess and to investigate the reasons for the variations between the results of meta-analyses addressing the same question. STUDY DESIGN AND SETTING: We included systematic reviews, and the trials that they included, on the use of implantable cardiac defibrillator (ICD) in patients with nonischemic cardiomyopathy. We assessed the variation between meta-analyses pooled effect estimates by calculating …