Within- and between-subject biological variation of hemostasis parameters in a study of 26 healthy individuals

Abstract Objectives The study aimed to estimate the biological variation (BV) of routine coagulation tests, including prothrombin time (PT), activated partial thromboplastin time (aPTT), and fibrinogen, in a healthy population to enhance the accuracy of laboratory results and improve diagnosis and treatment decisions. Methods The study included 26 healthy volunteers over 10 weeks; samples were collected weekly. The within-subject BV (CVI) and between-subject BV (CVG) were calculated for each parameter, and the index of individuality (II) and reference change values (RCV) were determined. All tests were performed in duplicate on the Roche Cobas T-711 coagulation analyzer. Results Fibrinogen exhibited the highest BV, with a CVI of 11 % and CVG of 17.4 %. The aPTT test had a CVI of 5.8 %, a CVG of 8.4 %, and an II of 0.91. The PT test had a CVI of 3.2 %, a CVG of 5.8 %, and an II of 0.73. The RCV values ranged from −7.5 to 8.1 for PT, −12.7 to 14.6 for aPTT, and −22.7 to 29.4 for fibrinogen. Conclusions The study underscores the significant biological variation in routine hemostasis parameters, such as PT, APTT, and fibrinogen, which impacts clinical diagnoses and treatment decisions. Despite certain limitations, the findings offer valuable insights for clinicians and suggest that future research should include more parameters for a comprehensive understanding of biological variations in hemostasis testing.