The importance of the Biological Variation Data Critical Appraisal Checklist when designing experimental studies on biological variation. Comparison of two papers reporting biological variation results for S100-β and neuron-specific enolase proteins.

© 2019 Biomedia. All rights reserved. The Biological Variation Data Critical Appraisal Checklist (BIVAC) has been designed to evaluate biological variation (BV) studies and the reliability of the associated BV estimates. To illustrate its utility, two studies delivering within-subject BV (CV I ) data for S100-β protein and neuron-specific enolase (NSE), markers typically used for melanoma and neuroendocrine tumors, respectively, were appraised using BIVAC. Data from the European Biological Variation Study (EuBIVAS) and the recently published Johnson et al. study (ref n 11) were scored using the 14 BIVAC quality items (QI), with alternatives A, B, C and/or D to verify whether the elements required to obtain reliable BV data, were present and appropriately documented. Grade A indicates compliance with all the QIs and D indicates non compliance. The sizes of the confidence interval (CI) around the CV I estimates were also compared. Johnson’s study received a BIVAC grade C, EuBIVAS a grade A. EuBIVAS is a large scale study, with