Incidence of cholecystectomy and risk associated with use of oral estrogen menopausal hormone therapy
| Variable | No. of women* | No. who had cholecystectomy* | Age-adjusted HR (95% CI) | Multivariate HR† (95% CI) |
|---|---|---|---|---|
| Never used menopausal hormone therapy | 18 694 | 824 | 1.00 (ref) | 1.00 (ref) |
| Ever used oral estrogen therapy | 16 736 | 625 | 1.06 (0.96–1.16) | 1.16 (1.06–1.27) |
| Estradiol alone | 1 713 | 77 | 1.25 (0.99–1.57) | 1.27 (1.01–1.60)‡ |
| Estradiol with progestagen | 15 261 | 533 | 1.03 (0.93–1,13) | 1.10 (0.99–1.21) |
| Equine estrogen alone | 585 | 44 | 1.48 (1.09–2.00) | 1.53 (1.11–2.11)§ |
| Equine estrogen with progestagen | 599 | 23 | 0.95 (0.67–1.34) | 0.68 (0.43–1.09) |
Note: CI = confidence interval, HR = hazard ratio, ref = reference group.
↵* Data on use of menopausal hormone therapy were missing for 6 250 women, including 211 who reported undergoing cholecystectomy during follow-up.
↵† Adjusted for body mass index, parity, hypercholesterolemia, diabetes and education level.
↵‡ p = 0.2 for comparison of estradiol alone v. estradiol with progestagen; p = 0.4 for comparison of estradiol alone v. equine estrogen alone.
↵§ p = 0.01 for comparison of equine estrogen alone v. equine estrogen with progestagen.