For WGs that have decided to conduct meta-analyses of summary data provided by each study, phenotypes are defined and variables recoded (if necessary) by all studies so that genome-wide analyses can be done on comparable measures. Analyses of individual study data are performed by each study's investigators as soon as that study's phenotype and genotype data have completed the cleaning process. The summary statistics are then provided to the WG member leading the meta-analysis. Where the WG has decided on an analysis of pooled individual-level data, the CC applies the appropriate algorithms to each dataset to harmonize each study's data according to the WG's definition, pools the data into one combined dataset, and provides this to the investigators doing the analysis.
