Table 21.

Risk of VTE When Siblings Were Diagnosed With VVs Excluding Those Without Siblings

Siblings' Diseases	All VTE
	O	SIR	95% CI
Uncomplicated VVs	4240	1.27*	1.23 to 1.31
Complicated VVs	796	1.61*	1.50 to 1.73
All VVs	4929	1.30*	1.27 to 1.34

SIRs are adjusted for age, sex, time period, geographic region of residence, and socioeconomic status. O indicates observed number of cases; SIR, standardized incidence ratio; VTE, venous thromboembolism; VVs, varicose veins.

^*95% CI does not include 1.00.