Systematic review and meta-analysis of within-subject and between-subject biological variation data of coagulation and fibrinolytic measurands.

Objectives: The diagnosis and monitoring of bleeding and thrombotic disorders depend on correct haemostatic measurements. The availability of high-quality biological variation (BV) data is important in this context. Many studies have reported BV data for these measurands, but results are varied. The present study aims to deliver global within-subject (CV) and between-subject (CV) BV estimates for haemostasis measurands by meta-analyses of eligible studies, by assessment with the Biological Variation Data Critical Appraisal Checklist (BIVAC).

Methods: Relevant BV studies were graded by the BIVAC. Weighted estimates for CV and CV were obtained via meta-analysis of the BV data derived from BIVAC-compliant studies (graded A-C; whereby A represents optimal study design) performed in healthy adults.

Results: In 26 studies BV data were reported for 35 haemostasis measurands. For 9 measurands, only one eligible publication was identified and meta-analysis could not be performed. 74% of the publications were graded as BIVAC C. The CV and CV varied extensively between the haemostasis measurands. The highest estimates were observed for PAI-1 antigen (CV 48.6%; CV 59.8%) and activity (CV 34.9%; CV 90.2%), while the lowest were observed for activated protein C resistance ratio (CV 1.5%; CV 4.5%).

Conclusions: This study provides updated BV estimates of CV and CV with 95% confidence intervals for a wide range of haemostasis measurands. These estimates can be used to form the basis for analytical performance specifications for haemostasis tests used in the diagnostic work-up required in bleeding- and thrombosis events and for risk assessment.