Skimming a recent paper in Clinical Chemistry (subscription required), I came across quality improvement paper that uses a process I had never heard of – the A6 cycle: (Ask, Acquire, Appraise, Apply, and Assess). This is the reason for the picture above*.
But the paper also features meta-analysis as a way to summarize an overall effect. Many studies have flaws including bias. See this paper by John P. A. Ioannidis with the catchy title “Why Most Published Research Findings Are False.” One needs to find studies without bias, which are rare, not to summarize all comers.
*It was pointed out to me that I have only 5 A’s. Analysis is the 6th.