International Active Surveillance Study of Women Taking Oral Contraceptives (INAS-OC)

Study Overview
=================
Brief Summary
-----------------
The study compares the short- and long-term risks of a 24-day regimen of a drospirenone-containing oral contraceptive with the risks of established oral contraceptives in a study population that is representative for the actual users of the individual preparations.

Detailed Description
-----------------
Drospirenone is a novel progestogen with antiandrogenic and antimineralocorticoid properties. A large active post-marketing surveillance study has demonstrated that a 21-day regimen of 3mg drospirenone and 30mcg ethinylestradiol can be used safely for oral contraception. This study investigates the risks of short and long-term use of a 24-day regimen of drospirenone/ethinylestradiol in comparison to established OCs in a study population that is representative of the actual users of the individual preparations. INAS-OC is a prospective, controlled, non-interventional cohort study with two study arms: OCs containing drospirenone and OCs containing any other progestogen. The study was started in the USA in April 2005 and was extended to several European countries in September 2008 based on the launch status of the 24-day regimen. New users of an OC (starters, switchers without a pill intake break and recurrent users with a pill intake break [same or different OC]) are accrued by a network of prescribing physicians. Baseline and follow-up information are collected via a self-administered questionnaire. Data analysis will be based on life-table methods comparing the cohorts. All analyses will make allowance for confounding, using methods that will include multivariate techniques such as Cox regression.

Official Title
-----------------
International Active Surveillance Study of Women Taking Oral Contraceptives (INAS OC)

Conditions
-----------------
Contraception

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: First-ever OC users (starters) Women switching OC use without a pill intake break (switchers) Recurrent users with a pill intake break (recurrent users) Women willing to participate in the active surveillance Exclusion Criteria: Women who do not agree to participate Long-term users
Sexes Eligible for Study
-----------------
Female

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| 1<br>Users of OCs containing DRSP | |
| 2<br>Users of OCs containing other progestins | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Venous Thromboembolism (VTE); Hazard Ratio for DRSP-24 Day vs. Non-DRSP OCs | Venous thromboembolism (VTE) hazard ratio for oral contraceptives containing both drospirenone (DRSP) and ethinylestradiol (EE) in a 24-day regimen or any oral contraceptive without DRSP. | Within 60 months | 
| Arterial Thromboembolism (ATE), Hazard Ratio for DRSP-24 Day vs. Non-DRSP OCs | Arterial thromboembolism (ATE) in women using oral contraceptives containing both drospirenone (DRSP) and ethinylestradiol (EE) in a 24-day regimen or any oral contraceptive without DRSP. Cox regression analysis was not carried out. In accordance to the analysis plan, hazard ratios were only to be calculated if a minimum of 5 confirmed events were available in each of the comparison groups. | Within 60 months | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Drospirenone, Safety, INAS