What is pathway-level meta-analysis of MS peaks?

For the pathway-level meta-analysis, each study undergoes the typical steps of calculating m/z level statistics (if not already done), putative metabolite annotation, followed by pathway activity prediction.

Once this is complete for all studies, all pathway results are combined to create a unified matrix of pathway-level results (keeping only pathways found across all-studies). Pathway activity scores are then combined using one of several p-value integration methods.