Table 5:

Sensitivity analysis of risk of cholecystectomy associated with menopausal hormone therapy restricted to women exposed to only one type of regimen

Variable	No. of women*	No. who had cholecystectomy*	Multivariate HR† (95% CI)
Never used menopausal hormone therapy	18 694	824	1.00 (ref)
Oral estradiol alone	277	20	1.83 (1.18–2.86)‡
Oral estradiol with progestagen	5 930	232	1.18 (0.89–1.55)
Oral equine estrogen alone	157	17	1.90 (1.17–2.11)§
Oral equine estrogen with progestagen	91	10	1.64 (0.88–3.06)
Transdermal estrogen alone	2 166	101	1.20 (0.97–1.47)¶
Transdermal estrogen with progestagen	15 481	674	1.05 (0.95–1.16)
Other estrogen	1 552	38	0.93 (0.67–1.29)

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 = 0.06 for comparison of oral estradiol alone v. oral estradiol with progestagen; p = 0.9 for comparison of oral estradiol alone v. oral equine estrogen alone; p = 0.08 for comparison of oral estradiol alone v. oral transdermal estrogen alone; p = 0.02 for comparison of oral estradiol alone v. other estrogen.

^§p = 0.7 for comparison of oral equine estrogen alone v. oral equine estrogen with progestagen.

^¶p = 0.3 for comparison of transdermal estrogen alone v. transdermal estrogen with progestagen.