Table 2. Relative Risk of and Tetrachoric Correlation for AF in First-Degree Relatives.

Sex of Affected Relative	Sex of Individual	No. of Cases	Prevalence, %a	Relative Risk (95% CI)b	Tetrachoric Correlation (95% CI)b
Any Relative
Male	Male	1248	1.2	2.20 (2.06-2.35)	0.10 (0.09-0.10)
	Female	701	0.9	2.01 (1.87-2.16)	0.11 (0.10-0.11)
	All	1949	1.1	2.20 (2.09-2.31)	0.10 (0.10-0.11)
Female	Male	1352	1.7	1.79 (1.70-1.88)	0.18 (0.18-0.19)
	Female	335	0.7	1.59 (1.40-1.81)	0.11 (0.10-0.11)
	All	1687	1.4	1.79 (1.71-1.88)	0.17 (0.16-0.17)
All	Male	2493	1.4	1.93 (1.85-2.01)	0.11 (0.11-0.12)
	Female	1016	0.8	1.84 (1.73-1.96)	0.08 (0.07-0.08)
	All	3509	1.2	1.96 (1.88-2.04)	0.10 (0.10-0.11)
Parent
Male	Male	784	0.8	2.03 (1.89-2.17)	0.30 (0.29-0.31)
	Female	139	0.2	1.43 (1.21-1.69)	0.22 (0.20-0.23)
	All	923	0.6	1.98 (1.86-2.11)	0.29 (0.28-0.29)
Female	Male	1264	1.7	1.78 (1.69-1.88)	0.36 (0.35-0.37)
	Female	224	0.5	1.46 (1.28-1.66)	0.31 (0.30-0.33)
	All	1488	1.3	1.77 (1.69-1.86)	0.36 (0.35-0.36)
All	Male	1973	1.2	1.83 (1.76-1.91)	0.32 (0.32-0.33)
	Female	349	0.3	1.42 (1.28-1.58)	0.26 (0.25-0.27)
	All	2322	0.8	1.81 (1.74-1.89)	0.32 (0.31-0.32)
Offspring
Male	Male	362	12.2	2.72 (2.47-2.99)	0.33 (0.32-0.34)
	Female	535	9.8	2.28 (2.11-2.47)	0.36 (0.35-0.37)
	All	897	10.7	2.50 (2.35-2.65)	0.34 (0.33-0.35)
Female	Male	65	6.5	1.84 (1.47-2.32)	0.20 (0.18-0.23)
	Female	105	6.6	1.92 (1.60-2.30)	0.29 (0.27-0.31)
	All	170	6.6	1.93 (1.67-2.23)	0.25 (0.23-0.26)
All	Male	426	10.8	2.53 (2.32-2.77)	0.31 (0.30-0.31)
	Female	639	9.1	2.22 (2.06-2.38)	0.35 (0.34-0.35)
	All	1065	9.7	2.39 (2.26-2.52)	0.32 (0.32-0.33)
Full Sibling
Male	Male	121	2.6	2.45 (1.97-3.04)	0.36 (0.34-0.38)
	Female	31	0.9	1.68 (1.19-2.38)	0.32 (0.29-0.35)
	All	152	1.8	2.27 (1.88-2.74)	0.35 (0.34-0.37)
Female	Male	26	1.6	1.91 (1.31-2.79)	0.33 (0.30-0.36)
	Female	9	0.7	3.14 (1.37-7.19)	0.25 (0.25-0.06)
	All	35	1.2	2.13 (1.49-3.03)	0.31 (0.29-0.34)
All	Male	147	2.3	2.34 (1.93-2.83)	0.36 (0.34-0.37)
	Female	40	0.8	1.88 (1.36-2.61)	0.31 (0.29-0.34)
	All	187	1.7	2.25 (1.88-2.68)	0.35 (0.33-0.36)
Twin
Male	Male	4	16.7	17.37 (3.9-77.40)	0.71 (0.63-0.80)
	Female	0	0	NA	NA
	All	4	13.3	14.78 (3.38-64.71)	0.70 (0.62-0.79)
Female	Male	0	NA	NA	NA
	Female	0	NA	NA	NA
	All	0	NA	NA	NA
All	Male	4	14.3	14.14 (3.36-59.51)	0.70 (0.61-0.78)
	Female	0	NA	NA	NA
	All	4	9.1	12.15 (2.94-50.21)	0.65 (0.57-0.73)
Spouse
Female	Male	1311	5.4	1.18 (1.12-1.24)	0.25 (0.24-0.25)
Male	Female	1819	2.8	1.14 (1.09-1.19)	0.23 (0.22-0.23)
All	All	3130	3.5	1.15 (1.10-1.20)	0.22 (0.21-0.22)

Abbreviations: AF, atrial fibrillation; NA, not applicable (because of no AF cases with affected twin).

^aPrevalence was equal to recurrence risk.

^bAdjusted for age, sex, occupation, income level, urbanization of residence, and family size.