Associations between coagulation factor XII, coagulation factor XI, and stability of venous thromboembolism: A case-control study

Table 5 Age stratified association between factor XII antigen and factor XI antigen and the stability of deep venous thrombosis: Comparisons between patients with deep venous thrombosis and deep venous thrombosis and pulmonary embolism

	Cut-off1	DVT	DVT + PE	χ2	OR	95%CI	P value
FXII:Ag
≤ 60 yr	≤ 68.485	26	25	0.406	0.72	0.262-1.980	0.524
	> 68.485	13	9
> 60 yr	≤ 68.485	13	12	0.013	1.083	0.273-4.293	0.593
	> 68.485	6	6
FXI:Ag
≤ 60 yr	≤ 130.117	35	23	5.432	4.185	1.188-14.746	0.020
	> 130.117	4	11
> 60 yr	≤ 130.117	16	14	-	1.905	0.384-9.444	0.3462
	> 130.117	3	5

¹Cut-off values for factor XII antigen (FXII:Ag) and factor XI antigen (FXI:Ag) were selected based on the 95^th percentiles of FXII:Ag and FXI:Ag in patients with deep venous thrombosis + pulmonary embolism.

²Fisher’s exact test was applied because < 40 patients were included in subgroup of patients aged > 60 years.

FXII:Ag: Factor XII antigen; FXI:Ag: Factor XI antigen; CI: Confidence interval; DVT: Deep venous thrombosis; OR: Odds ratio; PE: Pulmonary embolism.