Table 2.

Proportional Hazards Model of Correlates of Greater Duration of Use of Postmenopausal Hormone Replacement Therapy

	Adjusted Risk Ratio*	95% Confidence Interval
Age	0.98	0.97 to 0.99
White race	1.63	1.32 to 2.02
Estrogen preparation
Conjugated estrogens 0.625 mg	Reference	—
Esterified estrogens 0.625 mg	2.32	1.66 to 3.24
All other estrogens	0.52	0.41 to 0.66
Change in preparation during course of therapy	5.62	4.33 to 7.25
Provider specialty†
Internist	Reference	—
Gynecologist	0.84	0.71 to 0.99
All other providers	0.74	0.51 to 1.09

^*Adjusted for median household income; number of medical encounters in year prior to starting HRT; pap smear, mammography and bone densitometry in the year prior to starting HRT; use of a progestin; prescriber gender. All variables were significantly associated with duration of use in unadjusted analyses except bone density testing, number of medical encounters in the year prior to starting therapy, and provider specialty.

^†Specialty of the provider of the initial HRT prescription.