Method of Contraception and Risk of Ovarian Cancer Data.

Abstract The data presented here were obtained for New Zealand nationwide population-based case-control analysis undertaken to assess the association between ovarian cancer and depot medroxyprogesterone acetate (DMPA), intrauterine contraceptive devices (IUDs), and vasectomy of a woman's sexual partner [1] . Approval to conduct the research was obtained from Southern Health and Disability Ethics Committee (13/STH/26) and the University of Canterbury Ethics Committee (HEC 2013/08). Recruitment of participants and data collection were conducted between 1st May 2013 and 31st October, 2015. The research involved women aged 35 to 69 years. Cases were women with a diagnosis of incident ovarian cancer recruited from the New Zealand Cancer Registry (NZCR) and had to be listed on the electoral roll. Controls were randomly selected from the New Zealand electoral roll, frequency matched to cases by 5-year age groups (case to control ratio 1:5). Women with a prior history of ovarian cancer or bilateral oophorectomy were excluded. All participants had to be able to communicate in English. A structured postal questionnaire was used to gather information on socio-demographic characteristics, contraceptive use and potential confounding factors. Data were analysed using IBM Statistical Package for the Social Sciences (IBM SPSS statistics 22). Odds ratios adjusted for age were calculated using the method of Mantel and Haenszel [2] . For multivariable analyses, binary logistic regression was used. Description of study participants and age-adjusted and multivariable analyses of the association between ever-use and specifics of use of DMPA, IUDs, and vasectomy were presented in a journal article [1] . Here, we present data from analyses of the risk of ovarian cancer by histological type associated with the use of DMPA, IUDs and ever having had a vasectomised partner. In addition, analyses assessing the association between ovarian cancer and these contraceptives restricted to ever-users and never-users of hormonal contraceptives (defined as oral contraceptives or DMPA) are presented. Data from analyses of the association between history of tubal ligation and the risk of ovarian cancer are also presented. These data, including the findings of a related study [1] and the raw data, can be included in a collaborative analysis of existing studies undertaken to assess the association between IUDs, long-acting progestogen-based contraceptives, and partner vasectomy and the risk of ovarian cancer. • Knowledge of the effects of contraceptives on the health of users is important in assessing the risks and benefits of a contraceptive when choosing a method. Contraceptives are widely used and use may span months or years; therefore, even a small effect on the risk of ovarian cancer may have a great impact on the incidence of disease in the general population. • The inverse associations of both partner vasectomy and use of DMPA with the occurrence of ovarian cancer provide additional important non-contraceptive benefits of vasectomy and DMPA. This may provide alternative contraceptive options for women who wish to lower their risk of ovarian cancer but cannot use oral contraceptives. • These data, including the findings of a related study [1] and the raw data, can be included in a collaborative analysis of existing studies undertaken to assess the association between IUDs, long-acting progestogen-based contraceptives, and partner vasectomy and the risk of ovarian cancer.