Factors affecting mortality in a large cohort study with special reference to oral contraceptive use.

Journal article

BACKGROUND: This analysis updates mortality in the Oxford-Family Planning Association (Oxford-FPA) contraceptive study, with emphasis on oral contraceptive (OC) use. STUDY DESIGN: The Oxford-FPA study includes 17,032 women recruited from 1968-1974 at contraceptive clinics, aged 25-39 years, using OCs a diaphragm or an intrauterine device. Follow-up has been to March 2009; by then, 1715 women had died. RESULTS: The rate ratio (RR) for overall mortality was 0.87 (CI 0.79-0.96), comparing ever-users of OCs with never-users. The RR for fatal cervical cancer was increased (7.3), but the CIs were very wide (1.2-305). There was no association between ever-use of OCs and mortality from breast cancer (RR 1.0, CI 0.8-1.2), nor was fatal breast cancer related to duration of OC use. OC use strongly protected against death from other uterine cancer and ovarian cancer; RRs for ever-use of OCs were 0.3 (CI 0.1-0.8) and 0.4 (CI 0.3-0.6), respectively. Protection increased with duration of OC use and persisted more than 20 years after cessation. Circulatory disease mortality was not increased, the RR for ever-use of OCs being 0.9 (CI 0.7-1.1). The overall mortality RR for all women smoking 15+ cigarettes daily was 2.25 (CI 1.99-2.53) and, for all women with a body mass index of 28+ kg/m(2), was 1.33 (CI 1.07-1.64). CONCLUSIONS: Long-term follow-up strongly suggests that OC use slightly reduces all cause mortality.

Authors: Vessey, M; Yeates, D; Flynn, S

• Publication status: Published
• Journal: Contraception
• Volume: 82
• Issue: 3
• Pages: 221-229
• Publication date: 2010-09-01
• DOI: 10.1016/j.contraception.2010.04.006
• EISSN: 1879-0518
• ISSN: 0010-7824
• Language: English
• Keywords: Contraceptives, Oral, Hormonal; Adult; Humans; Contraception; Cohort Studies; Genital Neoplasms, Female; Questionnaires; Mortality; Female