TABLE 2.

Characteristics of the Danish Twin Registry With Regard to the SF-12 Response

Zygosity and sex	Number of twins	Response to SF-12 (%)	SF-12 MCS median (2.5–97.5th percentile)	SF-12 PCS median (2.5–97.5th percentile)
All	33,794	29,619 (88)	54.4 (27.9–61.5)	55.9 (27.9–62.4)
Females	18,461	15,884 (86)	53.5 (27.1–61.7)	55.9 (26.7–62.7)
Males	15,333	13,735 (90)	55.0 (30.1–61.4)	55.9 (30.3–62.1)
MZ	9,000	8,076 (90)	53.7 (27.1–61.3)	56.3 (29.6–62.7)
MZ females	5,024	4,471 (89)	53.2 (25.6–61.3)	56.3 (27.9–63.0)
MZ males	3,976	3,605 (91)	55.0 (29.3–61.2)	56.1 (32.5–62.1)
ssDZ	12,877	11,229 (87)	54.7 (28.1–61.5)	55.9 (27.5–62.3)
ssDZ females	6,785	5,770 (85)	53.5 (27.2–61.5)	55.8 (26.1–62.6)
ssDZ males	6,092	5,459 (90)	55.1 (30.3–61.5)	55.9 (29.8–62.0)
osDZ	11,917	10,314 (87)	54.6 (28.6–61.7)	55.8 (27.1–62.3)
Twins from complete pairs	22,744	20,197 (89)	54.3 (28.4–62.5)	55.9 (28.7–62.3)
Twins from incomplete pairs	11,050	9,422 (85)	54.6 (27.2–62.0)	55.7 (26.4–62.5)

Note: ssDZ = same-sexed dizygotic twin pairs; osDZ = opposite-sexed dizygotic twin pairs.