Critical appraisal and meta-analysis of biological variation estimates for kidney related analytes.

Excluding the studies performed pre-standardisation did not lead to different BV estimates and meta-analyses performed separately for pre-and post-standardisation studies produced similar BV estimates with overlapping CIs. For each analyte, CV SB I sb estimates from all the different subgroups with 95% CI for the point estimate are presented (Figures 1-6). When publications reported separate estimates for different subgroups, these estimates were first combined to provide a common estimate by applying the weighted mean on the point estimates and corresponding CIs. [Extracted from the article]