Coding:

Coding,  the process by which the published papers in our sample were read, reviewed, and  documented, was done by C.C.W., W.D.B., J. W., and T.E.N. Articles used were  the result of a PubMed search over the past 10 years. At the onset, 1086 
...
genetic studies, and genome-wide association studies were excluded.  Meta-analyses were excluded to avoid redundancy, as we had already coded their  constituent studies individually. Studies combining original research with  meta-analysis were included so as to not exclude original research. Each (See Prisma Diagram).

Each  person was partnered with another so that all of the coding process was reviewed once over. The papers were analyzed for nine specific  pieces of information: outcome, measurement device, metric, method of  aggregation, primacy of outcome, whether the outcome was a harm or side effect