Incidence of cholecystectomy and risk associated with use of 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 menopausal hormone therapy | 45 984 | 1 784 | 1.01 (0.93–1.10) | 1.10 (1.01–1.20) |
| Oral estrogen | 16 736 | 625 | 1.10 (1.00–1.20) | 1.16 (1.06–1.27)‡ |
| Oral estrogen alone | 2 229 | 118 | 1.36 (1.03–1.65) | 1.38 (1.14–1.67)§ |
| Oral estrogen with progestagen | 15 645 | 555 | 1.03 (0.93–1.13) | 1.09 (0.99–1.20) |
| Transdermal estrogen | 33 584 | 1 300 | 0.97 (0.89–1.04) | 1.01 (0.94–1.10) |
| Transdermal estrogen alone | 9 488 | 361 | 1.06 (0.95–1.19) | 1.04 (0.93–1.17) |
| Transdermal estrogen with progestagen | 30 444 | 1 165 | 0.93 (0.87–1.01) | 0.99 (0.91–1.07) |
| Other estrogen | 6 709 | 187 | 1.01 (0.87–1.17) | 1.03 (0.89–1.20) |
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 educational level.
↵‡ p = 0.03 for comparison of oral estrogen v. transdermal estrogen; p = 0.2 for comparison of oral estrogen v. other estrogen.
↵§ p = 0.03 for comparison of oral estrogen alone v. oral estrogen with progestagen.