title: Oral contraceptive oestrogen and progestin potencies and the incidence of deep venous thromboembolism.
abstract: To assess possible differences in the incidence of venous thrombosis and pulmonary embolism associated with oral contraceptives of varying hormonal potencies, the authors conducted a retrospective cohort study in the 15-44 year old Michigan Medicaid population. Cohorts were defined by the progestin- and oestrogen-potencies of oral contraceptives in use at the time of follow-up as classified by an oral contraceptive potency scheme. Using the low-oestrogen-/low-progestin-potency formulations for reference (rate ratio = 1), adjusted rate ratios of 0.8 (95% CI: 0.5 to 1.3, P = 0.41) and 0.6 (95% CI 0.4 to 1.2, P = 0.13) were observed for intermediate-progestin-potency and high-progestin-potency formulations, respectively. Adjusted rate ratios of 1.4 (95% CI: 0.8 to 2.3, P = 0.21) and 2.6 (95% CI: 1.2 to 5.5, P = 0.01) were observed for intermediate- and high-oestrogen-potency formulations. These data suggest a dose-response relationship between oral contraceptive oestrogen potency and venous thromboembolism, whereas no such evidence for a dose-response relationship between oral contraceptive progestin potency and venous thrombo-embolism was found.
authors.affiliation: Office of Epidemiology and Biostatistics, Food and Drug Administration, Rockville, MD 20857.
authors.forename: B B
authors.initials: BB
authors.lastname: Gerstman
authors.forename: J M
authors.initials: JM
authors.lastname: Piper
authors.forename: J P
authors.initials: JP
authors.lastname: Freiman
authors.forename: D K
authors.initials: DK
authors.lastname: Tomita
authors.forename: D L
authors.initials: DL
authors.lastname: Kennedy
authors.forename: W J
authors.initials: WJ
authors.lastname: Ferguson
authors.forename: R C
authors.initials: RC
authors.lastname: Bennett
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D003278:Contraceptives, Oral, Hormonal / Q000009:adverse effects*; D045166:Estradiol Congeners / Q000008:administration & dosage / Q000009:adverse effects*; D005260:Female; D006801:Humans; D015994:Incidence; D008824:Michigan / Q000453:epidemiology; D011372:Progestins / Q000008:administration & dosage / Q000009:adverse effects*; D012189:Retrospective Studies; D013924:Thrombophlebitis / Q000139:chemically induced* / Q000453:epidemiology
chemical_list: D003278:Contraceptives, Oral, Hormonal; D045166:Estradiol Congeners; D011372:Progestins