Clinical trial NCT00335257: International Active Surveillance Study of Women Taking Oral Contraceptives (INAS-OC)
Official title: International Active Surveillance Study of Women Taking Oral Contraceptives (INAS OC)
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Contraception
Keywords: Drospirenone
Safety
INAS
Lead sponsor: Center for Epidemiology and Health Research, Germany
Sponsor class: OTHER
Collaborators: name: Bayer
First posted: 2006-06-09
Enrollment: 85109
Sex: FEMALE
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Women using oral contraceptives

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.

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

Primary outcomes:
measure: Venous Thromboembolism (VTE); Hazard Ratio for DRSP-24 Day vs. Non-DRSP OCs
timeFrame: Within 60 months
measure: Arterial Thromboembolism (ATE), Hazard Ratio for DRSP-24 Day vs. Non-DRSP OCs
timeFrame: Within 60 months
Secondary outcomes:
Other outcomes:
Locations:
city: Berlin
country: Germany
facility: Center for Epidemiology and Health Research
Study officials:
affiliation: Center for Epidemiology and Health Research, Berlin, Germany
name: Juergen C Dinger, MD, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Dinger J, Bardenheuer K, Heinemann K. Cardiovascular and general safety of a 24-day regimen of drospirenone-containing combined oral contraceptives: final results from the International Active Surveillance Study of Women Taking Oral Contraceptives. Contraception. 2014 Apr;89(4):253-63. doi: 10.1016/j.contraception.2014.01.023. Epub 2014 Feb 4.
citation: Dinger J, Do Minh T, Buttmann N, Bardenheuer K. Effectiveness of oral contraceptive pills in a large U.S. cohort comparing progestogen and regimen. Obstet Gynecol. 2011 Jan;117(1):33-40. doi: 10.1097/AOG.0b013e31820095a2.