A Reappraisal of Women’s Health Initiative Estrogen-Alone Trial: Long-Term Outcomes in Women 50–59 Years of Age

Table 1

Women’s Health Initiative Estrogen-Alone Trial, age of participants in estrogen/placebo (intervention) phase of trial.

Age at trial entry [3]; Years (%, Number)	Age at end of CEE/placebo intervention phase^a	Median age at randomization to CEE/placebo^b	Median age of starting postmenopausal hormone replacement therapy in USA population [15–19]: <55 years of age
50–59 y (30.9%^c, 3313)	55–67	55
60–69 y (45.2%, 4851)	65–77	64
70–79 y (24.0%, 2575)	75–87	74

A minority of participants were older at the end of the intervention phase than those listed in the upper limits of the estimated age brackets. (Start of intervention phase: December 1993; end of enrollment for intervention phase: October 1998; end of intervention phase: February 29, 2004; median duration of intervention phase: 7.2 years; end of reported trial follow-up: September 30, 2010 [1, 3].)
^bEstimates adjusted for age distribution of 50–59 y group (50–54 y/55–59 y = 1 : 1.37 ratio [14]) and for possible enrollment of participants at lower end of age bracket.
^cPercentages do not add to 100% because of rounding anomaly.
CEE: conjugated equine estrogens; USA: United States of America.
Derived from data provided in [1, 3, 14–19].