International Journal of Hematology

ISSN 2997-1036

International Journal of Hematology | Vol. 3, No. 6, June 2012 | pp. 41–48
DOI: 10.46882/2012/IJH/000030

Short Communication

Title: Baseline activated partial thromboplastin time and prothrombin time reference intervals in a healthy adult population

Names of Authors: B. C. Akpan¹, D. E. Usman²

Authors’ Affiliations: ¹Department of Haematology, University of Calabar, Calabar, Nigeria; ²Department of Clinical Pharmacology, Ahmadu Bello University, Zaria, Nigeria

Abstract: Coagulation screening reference intervals vary due to differences in reagent sensitivities, instrumentation, and local population characteristics. This study established local reference intervals for prothrombin time and activated partial thromboplastin time in 120 healthy, non-pregnant adult blood donors and hospital staff aged 18 to 50 years. Plasma samples were analyzed on an automated coagulation analyzer using standard thromboplastin and actin reagents. The computed 95% reference intervals for prothrombin time were 11.2 to 14.5 seconds (mean = 12.8 ± 0.8 seconds). For activated partial thromboplastin time, the reference interval was 28.4 to 40.2 seconds (mean = 34.3 ± 2.9 seconds). No significant differences were observed across gender or age groups (P > 0.05). These calculated local ranges differed from manufacturer package inserts, which tended to underestimate upper limits. Establishing population-specific reference intervals prevents the over-investigation of healthy individuals and improves the accuracy of pre-operative coagulation assessments.

Keywords: Prothrombin time, activated partial thromboplastin time, reference intervals, coagulation, blood donors

Manuscript Timeline: Received: March 18, 2012; Revised: April 25, 2012; Accepted: May 14, 2012; Published: June 20, 2012