Age- and Sex-Related Reference Intervals of Prothrombin Time and Activated Partial Thromboplastin Time

Background: Due to the differences in reference intervals (RIs) for clinical parameters between geographical regions, each laboratory needs to establish its own RIs to aid in effective clinical diagnosis and management. This study developed age- and sex-specific RIs for prothrombin time (PT) and activated partial thromboplastin time (aPTT) among apparently healthy adults in Tamale, Ghana. Methods: This cross-sectional study recruited 206 apparently healthy individuals, aged 18-46 and residing in Tamale, Northern Region of Ghana. The PT and aPTT were determined using the HumaClot Duo Plus semi-automated coagulation analyzer. The data were analyzed using SPSS version 26. The RIs for PT and aPTT were established at 2.5th-97.5th percentiles. Results: The RIs for PT and aPTT were 10.2-13.37 seconds and 20.41–35.28 seconds, respectively. Females had relatively wider PT RI values than their male counterparts [(9.91–13.39) vs. (10.10–13.37) seconds]. Conversely, males showed relatively wider RIs for aPTT as compared to the female population [(19.86–35.47) vs. (21.40–35.20) seconds]. Adults between the ages of 31-46 years had the widest PT RIs (10.10–13.55) seconds, while the 18-20 years age group had the lowest range (10.10–12.85) seconds. For aPTT, individuals aged 18 -20 years had relatively wider RIs of 19.50–35.25 seconds than the rest of the age groups. A weak positive correlation was observed between PT and age (r =0.166, p=0.017), while aPTT showed a weak inverse correlation with age (r= -0.203, p=0.003). Conclusion: Relatively wider RIs for PT (10.02–13.37 seconds) and aPTT (20.41–35.28 seconds) were found among the population in Northern Ghana. PT correlated positively with age, while aPTT inversely correlated with age. Females had relatively wider PT-RI values than their male counterparts. Conversely, males showed relatively wider RIs for aPTT than the female group. Doi: 10.28991/SciMedJ-2023-05-03-01 Full Text: PDF