Determinants of estrogen replacement therapy use in northern Italy.

Socio-demographic characteristics, general lifestyle habits and menstrual and reproductive history were compared in 83 women aged 45 years or more who had at some time used estrogen replacement therapy (ERT) and 1759 never users interviewed as control subjects in the framework of a large case-control survey on risk factors for gynecological neoplasms conducted in Northern Italy. ERT use was strongly related to social class and level of education. The odds ratio of "ever" use was 3.0 (95% confidence interval, CI, 1.8-5.1) for women with 12 or more years of education, compared with those with less than 7 years. No relationship emerged between marital status and ERT use, but parous women tended to be less frequently ever users than nulliparous, and ERT use decreased with increasing number of births (chi 2 1 trend = 10.51, p. = 0.001). Post-menopausal women reported more frequent ERT use than peri-menopausal ones, and among post-menopausal subjects the use was more frequent in those reporting earlier age at menopausal (chi 2 1 trend = 5.33, p = 0.02). There was no association between smoking habits and ERT use, but Quetelet's index was inversely related to the use of ERT.