The objective of this study is to characterize and compare the risks of short- and long-term use of NuvaRing® with marketed combined oral contraceptives.

This is a large, multinational, controlled, prospective, active surveillance study of women who are prescribed NuvaRing® or an oral contraceptive (OC). The study follows two cohorts. The cohorts consist of new users (starters and switchers) of two different groups of hormonal contraceptives:

• NuvaRing®
• marketed combined OCs (combined oral contraceptives)

NuvaRing® is a transparent and flexible contraceptive vaginal ring containing etonogestrel and ethinylestradiol (EE). The ring releases 15 mcg EE and 120 mcg etonogestrel daily. After insertion it remains in the upper part of the vagina for 21 days, followed by 7 ring-free days before a new ring is inserted.

The primary objective of this study is to characterize and compare the risks of short- and long-term use of NuvaRing® with marketed combined OCs. The main clinical outcomes of interest for the short and long-term follow-up are:

• Deep Venous Thrombosis (DVT)
• Pulmonary Embolism (PE)
• Acute Myocardial Infarction (AMI)
• Cerebrovascular Accidents (CVA)

Secondary objectives are:

• to analyze the drug utilization pattern of NuvaRing® and marketed OCs in a study population that is representative for typical use of the individual contraceptive methods under routine medical conditions
• to characterize the baseline risk of users of the individual formulations
• to assess the compliance of NuvaRing® users and users of marketed OCs
• to analyze the reasons for discontinuing the treatment with NuvaRing® and/or marketed OCs.

The study will use a non-interference approach to provide standardized, comprehensive, reliable information on these treatments in a routine clinical practice setting.

Study participants will be recruited via an international network of more than 1000 gynecologists. After study entry cohort members will be followed for a period of 30 to 48 months for rare serious safety outcomes. Regular, active contacts with the cohort members by the study team of the Berlin Center for Epidemiology and Health Research (ZEG), Germany will provide the necessary information on health-related events or changes in health status (= active surveillance).

Approximately 15,000 subjects per cohort will be recruited by participating physicians in order to provide approx. 86,000 women-years (WY) of observation. Subjects will be considered for enrollment in this study after the participating physician has determined that NuvaRing® or OC use is appropriate. There will be no specific inclusion/exclusion criteria. All women who are eligible are to be asked by their physician if they are willing to participate. As this a non-interventional study, the possibility to participate in the study should not be discussed with the patient before both - physician and patient - agree upon the prescription.

The study will be conducted in several European countries and the United States.

The study will be divided into 2 phases: a baseline survey which includes an initial consultation at baseline with a participating physician, and a follow-up phase which includes two follow-up contacts within the first year and then annual follow-up contacts for up to 4 years post-baseline.

The study will maintain scientific independence and will be governed by an independent Safety Monitoring and Advisory Council (SMAC). The Berlin Center for Epidemiology and Health Research (ZEG) and its research team will be accountable to the council in all scientific matters. The members of the council will be international experts in relevant scientific fields (e. g., epidemiology, drug safety, gynecology, cardiology, statistics, endocrinology).

Inclusion Criteria:

• women who are prescribed NuvaRing® or a combined oral contraceptive and who are new users (Starters, restarters or switchers) of the formulation

Exclusion Criteria:

• women who do not consent to participate in the study

Women prescribed hormonal contraceptives by gynecologists

All study participants that were not excluded due to protocol violations.

Information on adverse events was collected over a period of 4 years.

All study participants were asked for adverse events at each follow-up.

In non-experimental studies the possibility of bias and residual confounding can never be entirely eliminated. The findings may exclude large, but not small relative risks.