How many dreadful manuscripts describing the results of a meta-analysis are submitted to and rejected from journals each year? We cannot know, but many published meta-analyses do not use appropriate methods or contribute meaningfully to medical thought or patient care. Some journals avoid all meta-analyses, whereas others pride themselves on publishing only the best; still others are delighted to have anything to print in an era where the number of opportunities to publish greatly exceeds the number of valid observations.
Many have critically examined the methodology of meta-analysis, and others have set standards for their execution. Despite such guidance, meta-analyses continue to proliferate, but we should ask: do they really contribute? Esteemed organizations regard the conclusions of a well-executed meta-analysis as a higher level of evidence than a single well-done clinical trial. This commentary explains why this cannot possibly be true.