Table 2.

The relative risk of thrombosis depending on the level of factor VIII

FVIII:C IU/dL	Patients n (%)	Control n (%)	OR (95% CI)
<100	52 (17)	111 (37)	1 (reference category)
100–125	88 (29)	96 (32)	2.3 (1.3–3.8)
125–150	85 (28)	60 (20)	3.0 (1.6–5.7)
>150	76 (25)	34 (11)	(4.8) 2.3–10

Abbreviations: CI, confidence interval; FVIII, factor VIII; OR, odds ratio.

Note: Reprinted from The Lancet, Vol. 345, Koster T, Blann AD, Briët E, Vandenbroucke JP, Rosendaal FR, Role of clotting factor VIII in effect of von Willebrand factor on occurrence of deep-vein thrombosis, Pages 152–155. Copyright © 1995, with permission from Elsevier.⁶