Table 4

Positivity rates and patient characteristics by test ordered.*


Positivity
Fraction of positives which also had INR>1.3
Median Age
% Female

Protein S Functional
17.7%
21.2%
46
65.7%
Protein S Total Ag
4.8%
40.5%
47
63.0%
Protein S Free Ag
18.5%
25.0%
39
67.4%
Protein C Functional
13.7%
53.8%
46
65.4%
Protein C Total Ag
12.9%
33.3%
47
62.9%
Antithrombin Functional
7.5%
N/A
46
65.8%
Antithrombin Antigen
14.3%
N/A
46
65.3%
APC resistance
17.7%
N/A
46
65.7%
V Leiden mutation
12.3%
N/A
47
64.1%
Prothrombin G20210A mutation
4.9%
N/A
46
64.1%

*Positivity for V Leiden and prothrombin mutations includes both heterozygotes and homozygotes; for the remaining assays it includes all results falling below the lower limit of the reported reference interval.

Jackson et al. BMC Clinical Pathology 2008 8:3   doi:10.1186/1472-6890-8-3