Table 1 Descriptive characteristics for the singleton and twin study population (by 31 December 1995).

From: Postmenopausal hormone therapy and mortality before and after the Women’s Health Initiative study

 

Singletons

Twins

Total, n

52,388

15,261

Complete twin pairs/single twins

4220/6821

Age 46–50, n (%)

9836 (18.8)

3773 (24.7)

Years of education, median (IQR)

13 (8–13)

12 (7–13)

Deathsa, n (%)

1780 (18.1)

714 (18.9)

Age 51–55, n (%)

8320 (15.9)

3097 (20.3)

Years of education, median (IQR)

11 (7–13)

10 (7–13)

Deathsa, n (%)

2262 (27.2)

882 (28.5)

Age 56–60, n (%)

6688 (12.8)

2345 (15.4)

Years of education, median (IQR)

9 (7–13)

7 (7–13)

Deathsa, n (%)

2887 (43.2)

990 (42.2)

Age 61–65, n (%)

5885 (11.2)

1920 (12.6)

Years of education, median (IQR)

7 (7–13)

7 (7–13)

Deathsa, n (%)

3761 (63.9)

1272 (66.3)

Age 66–70, n (%)

5831 (11.1)

1133 (7.4)

Years of education, median (IQR)

7 (7–13)

7 (7–12)

Deathsa, n (%)

4830 (82.8)

962 (84.9)

Age 71–75, n (%)

5659 (10.8)

1068 (7.0)

Years of education, median (IQR)

7 (7–12)

7 (7–11)

Deathsa, n (%)

5396 (95.4)

1030 (96.4)

Age 76–80, n (%)

4254 (8.1)

817 (5.4)

Years of education, median (IQR)

Deathsa, n (%)

4232 (99.5)

817 (100)

Age 81 + , n (%)

5915 (11.3)

1108 (7.3)

Years of education, median (IQR)

Deathsa, n (%)

5910 (99.9)

1108 (100)

  1. IQR, interquartile range.
  2. aNumber of deaths from 31st of December 1995 until end of follow-up (31st of December 2020). Percentages are calculated for each age group.