Table 1.

Hazard ratios (95% confidence intervals) of coronary heart disease for continuous use of estrogen-plus-progestin therapy versus no hormone therapy use by years since baseline, the Women's Health Initiative (WHI) randomized trial and the Nurses' Health Study (NHS)

	Follow-up period
	Overall		≤2 years		>2 years
	WHI*	NHS†	WHI‡	NHS†	WHI§	NHS†
All women	1.69 (0.98-2.89)	1.30 (0.76-2.21)	2.36 (1.55-3.62)	1.71 (1.03-2.83)	1.33 (0.88-2.01)	1.07 (0.44-2.63)
p-value for heterogeneity ∥	0.50		0.34		0.67
Years since menopause
< 10	0.64 (0.21-1.99)	0.68 (0.24-1.91)	1.29 (0.52-3.18)	1.28 (0.43-3.86)	0.63 (0.27-1.52)	0.20 (0.03-1.54)
p-value for heterogeneity ∥	0.94		0.99		0.31
≥ 10	2.22 (1.20-4.11)	1.57 (0.86-2.85)	2.82 (1.73-4.60)	1.97 (1.11-3.47)	1.64 (1.01-2.65)	1.37 (0.54-3.45)
p-value for heterogeneity ∥	0.43		0.35		0.74
Age at baseline
50-59	1.47 (0.57-3.77)	0.91 (0.49-1.69)	2.69 (1.14-6.36)	1.80 (0.83-3.87)	1.22 (0.59-2.56)	0.54 (0.20-1.49)
p-value for heterogeneity ∥	0.40		0.49		0.20
≥ 60	1.76 (0.97-3.19)	1.92 (0.90-4.10)	2.30 (1.43-3.72)	1.69 (0.87-3.32)	1.36 (0.86-2.15)	2.10 (0.68-6.50)
p-value for heterogeneity ∥	0.86		0.47		0.49

^*Eight-year cumulative use

^†Women age 50 or older (from Appendix Table 3 of reference 3)

^‡Two-year cumulative use

^§Six-year cumulative use

^∥Wald test for heterogeneity of the hazard ratios from two studies