AzTrials
AzTrials

Estrogen TherapySHIELD-ETNCT07795606

An Observational Study to Learn How Mirena and Other Progestogen Treatments Are Used for Endometrial Protection in Women 40+ With a Uterus in the United States Receiving Estrogen Therapy, and Their Respective Health Outcomes

An observational study of Estrogen Therapy, run by Bayer at 2 sites in United States.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
Search all trials

Trial summary

This is an observational study in which researchers will use claims data already collected from women in the United States who received their usual care. The study will look at women aged 40 years and older who have a uterus and started estrogen therapy. Read more about this study

Who is it for?
Ages 40 years and older, women only
Conditions the study is for
Estrogen Therapy
What is being tested?
Estrogen therapy, Mirena levonorgestrel-releasing intrauterine system and Other progestogen therapy
Type of treatment
Medical device
How many people
456,000 participants
Where
2 sitesUnited States
Study dates
31 Aug 2026to 31 Dec 2026
Phase
Observational
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 40 years and older
  • Women only
  • No healthy volunteers
  • Adult, Older adult

Study population: The study population for the SHIELD-ET study are patients 40+ years of age with a uterus receiving estrogen therapy. Special populations or subpopulations among menopausal women (e.g. chemotherapy- or drug-induced menopause), as well as women without a uterus will be excluded.

Who may be able to join

  • At least one claim of estrogen therapy (ET) during the patient identification period (Index date: the first claim for ET)
  • Age ≥ 40 years at the index date
  • Patients with minimum continuous enrollment 12 months prior and 12 months at minimum after index date

Who cannot join

  • Women without a uterus (claims of hysterectomy) in the 12-month baseline period
  • Use of any hormonal contraception in the 12-month baseline period
  • Claims indicative of atypical endometrial hyperplasia or endometrial cancer or heavy menstrual bleeding (HMB)/abnormal uterine bleeding (AUB)/postmenopausal bleeding (PMB), or any treatment for late state or metastatic endometrial cancer, in the baseline period.
  • Claims in the baseline period for any of the treatments of interest
  • Claims of chemotherapy/endocrine therapy in the baseline period

Trial locations and contacts

2 sites in 1 country.

United States2 sites
  • Mirative MarketScan Commercial Claims and Encounters Database

    Ann Arbor, Michigan, 48108

  • Optum Clinformatics™ Data Mart (CDM)

    Eden Prairie, Minnesota, 55344

Other trials in United States

About this study

Official title: Study of Real-world Use of Hormonal Levonorgestrel Intra-uterine System for Endometrial Defense With Estrogen Therapy

This is an observational study in which researchers will use claims data already collected from women in the United States who received their usual care. The study will look at women aged 40 years and older who have a uterus and started estrogen therapy.

Estrogen therapy is often used to treat menopause symptoms, such as hot flashes and night sweats, or to help prevent bone loss. Women who take estrogen and still have a uterus usually also need a progestogen to help protect the lining of the uterus. Without this protection, the lining may become too thick. This can lead to endometrial hyperplasia and may increase the risk of endometrial cancer.

Read more

This study will look at how Mirena and other progestogen treatments are used in routine medical care to protect the lining of the uterus during estrogen therapy. Mirena is a small device placed in the uterus that releases the hormone levonorgestrel (a synthetic progestogen, similar to progesterone). In the United States, Mirena is approved for birth control and for treatment of heavy menstrual bleeding. Clinicians may also use it for endometrial protection during estrogen therapy. Bayer's Mirena levonorgestrel-containing intrauterine system (LNG-IUS) 52 mg is approved for endometrial protection during hormone therapy in over 100 countries outside of the US.

The main purpose of this study is gain insight into how different progestogen treatments are used in the context of estrogen therapy in women with a uterus, and the health outcomes linked with them. Researchers will describe how often women use estrogen alone, estrogen with Mirena, or estrogen with other progestogen treatments in the past 10 years. Researchers will also look at how often endometrial hyperplasia, endometrial cancer, abnormal or heavy bleeding, and hysterectomy occur in these groups over time.

The data will come from two U.S. health insurance claims databases: Optum Clinformatics Data Mart and MarketScan Commercial Claims and Encounters Database. The study period covers 2014 through 2025, depending on the database. Optum: January 2015-December 2025 and MarketScan: October 2014-September 2025, with patient identification periods of Optum: January 2016-December 2024 and MarketScan: October 2015-September 2024. Researchers will follow each participant's available data for at least 12 months before and at least 12 months after starting estrogen therapy, with follow-up of up to 10 years.

No study treatment will be given as part of this study. Researchers will only review anonymous health insurance claims data that were already collected during routine care.

Being tested
Estrogen therapy, Mirena levonorgestrel-releasing intrauterine system, Other progestogen therapy

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Estrogen therapyDrug

    Estrogen therapy prescribed during routine clinical practice and identified through prescription claims data. Exposure to estrogen therapy is determined using study-specific claims-based definitions.

  • Mirena levonorgestrel-releasing intrauterine systemDevice

    Also called Mirena LNG-IUS

    A levonorgestrel-releasing intrauterine system used for endometrial protection in women receiving estrogen therapy. Exposure is identified through Mirena insertion procedure codes and/or device codes in claims data. Contraception use of this product is not exposure of interest and baseline hormonal contraception is an exclusion criterion.

  • Other progestogen therapyDrug

    rogestogen therapy used for endometrial protection in women receiving estrogen therapy, including progesterone, synthetic progestins, Liletta LNG-IUS 52 mg, and combination estrogen-progestogen products. Exposure is identified through claims data. Contraceptive use of these products is not exposure of interest, and baseline hormonal contraception is an exclusion criterion.

Study groups in NCT07795606
Study groupRoleWhat they receive
Estrogen therapy (ET) unopposedWomen receiving estrogen therapy (ET) alone without evidence of concomitant progestogen use during the exposure assessment period.
Receives: Drug: Estrogen therapy
ET + Mirena LNG-IUSWomen receiving estrogen therapy (ET) with recurring prescription fills and evidence of Mirena levonorgestrel-releasing intrauterine system (LNG-IUS) use, identified through a Mirena insertion procedure code and/or device code during the exposure assessment period.
Receives: Device: Mirena levonorgestrel-releasing intrauterine system
ET + other progestogenWomen receiving estrogen therapy (ET) with recurring prescription fills and evidence of concomitant progestogen use other than Mirena LNG-IUS during the exposure assessment period. Other progestogen therapies include progesterone, synthetic progestins, Liletta LNG-IUS 52 mg, and combination estrogen-progestogen products.
Receives: Drug: Other progestogen therapy

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Proportion of patients receiving estrogen therapy

    Proportion of eligible female patients aged 40 years and older with a uterus who received at least one claim for estrogen therapy during the study period. The numerator is the number of patients with at least one estrogen therapy claim during the study period, and the denominator is the number of eligible female patients contributing at least one observable person-day during the study period.

    Measured: Retrospective analysis from January 2025 to December 2025

  2. Number of patients by treatment subgroup within 30 and 90 days of estrogen therapy initiation

    Number of patients in each treatment subgroup (ET unopposed, ET + Mirena LNG-IUS, and ET + other progestogen) within 30 and 90 days after initiation of estrogen therapy.

    Measured: Within 30 days and 90 days after estrogen therapy initiation during the study period (January 2025 to December 2025)

  3. Proportion of patients by treatment subgroup within 30 and 90 days of estrogen therapy initiation

    Proportion of patients in each treatment subgroup (ET unopposed, ET + Mirena LNG-IUS, and ET + other progestogen) within 30 and 90 days after initiation of estrogen therapy.

    Measured: Within 30 days and 90 days after estrogen therapy initiation during the study period (January 2025 to December 2025)

  4. Average length of estrogen therapy use

    The average length of estrogen therapy (ET) use will be expressed as the mean duration (in days) among all eligible patients. The length of ET use will be measured as the time from the first ET prescription date to the last ET prescription date, with a maximum allowable gap of 30 days between consecutive prescriptions to be considered continuous therapy.

    Measured: Retrospective analysis from January 2025 to December 2025

Secondary outcomes (11)
  1. Overall (10-year) incidence of atypical, non-atypical and unspecified endometrial hyperplasia, endometrial cancer, abnormal/unscheduled/heavy menstrual bleeding and hysterectomy

    Overall incidence of atypical, non-atypical, and unspecified endometrial hyperplasia, endometrial cancer, abnormal/unscheduled/heavy menstrual bleeding, and hysterectomy among patients in each treatment subgroup (ET unopposed, ET + Mirena LNG-IUS, and ET + other progestogen). Overall incidence will be evaluated over the 10-year study period. For each outcome, incident cases are defined as patients with at least one new claim for the condition of interest during follow-up. Only the first occurrence of each outcome after the index date will be counted as an incident event. Outcomes are assessed after completion of the 30- and 90-day exposure assessment periods, and only first incident events during follow-up are counted.

    Measured: Retrospective analysis from January 2016 to December 2025

  2. Annual incidence of atypical, non-atypical and unspecified endometrial hyperplasia, endometrial cancer, abnormal/unscheduled/heavy menstrual bleeding and hysterectomy

    Annual incidence of atypical, non-atypical, and unspecified endometrial hyperplasia, endometrial cancer, abnormal/unscheduled/heavy menstrual bleeding, and hysterectomy among patients in each treatment subgroup (ET unopposed, ET + Mirena LNG-IUS, and ET + other progestogen). For each outcome, incident cases are defined as patients with at least one new claim for the condition of interest during follow-up. Patients will be counted only in the calendar year of their first occurrence for each outcome.

    Measured: Annually from January 2016 through December 2025

  3. Participant demographic characteristics: age

    Measured: At baseline (within 12 months before the first estrogen therapy prescription claim [index date])

  4. Participant demographic characteristics: race

    Measured: At baseline (within 12 months before the first estrogen therapy prescription claim [index date])

  5. Participant demographic characteristics: ethnicity

    Measured: At baseline (within 12 months before the first estrogen therapy prescription claim [index date])

  6. Participant demographic characteristics: region

    Measured: At baseline (within 12 months before the first estrogen therapy prescription claim [index date])

  7. Participant demographic characteristics: health plan type

    Measured: At baseline (within 12 months before the first estrogen therapy prescription claim [index date])

  8. Gynecologic history: endometrial polyps, fibroids, adenomyosis, endometriosis

    Measured: At baseline (within 12 months before the first estrogen therapy prescription claim [index date])

  9. Clinical characteristics: relevant comorbidities

    Measured: At baseline (within 12 months before the first estrogen therapy prescription claim [index date])

  10. Clinical characteristics: Charlson Comorbidity Index (CCI)

    The CCI is a method of estimating the one-year mortality for a patient with certain comorbid conditions. Each comorbid condition is given a score of 1, 2, 3 or 6 based on the degree of mortality attributed to the condition. The scores are summed to yield a total index score which can be used to predict long-term survival. Higher scores indicate a greater comorbidity burden and a higher predicted risk of mortality.

    Measured: At baseline (within 12 months before the first estrogen therapy prescription claim [index date])

  11. Proportion of patients with a diagnosis of menopause

    Measured: At baseline (within 12 months before the first estrogen therapy prescription claim [index date])

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted31 Aug 2026
  2. Study start31 Aug 2026
  3. Primary completion30 Oct 2026 (estimated)
  4. Study completion31 Dec 2026 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Retrospective
Enrolment
456,000 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07795606
Sponsor's protocol ID
23357
Acronym
SHIELD-ET
Status last verified
Oct 2026
First submitted
26 Aug 2026
Last updated
19 Oct 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: Availability of this study's data will later be determined according to Bayer's commitment to the EFPIA/PhRMA "Principles for responsible clinical trial data sharing". This pertains to scope, timepoint and process of data access. As such, Bayer commits to sharing upon request from qualified researchers patient-level clinical trial data, study-level clinical trial data, and protocols from clinical trials in patients for medicines and indications approved in the US and EU as necessary for conducting legitimate research. This applies to data on new medicines and indications that have been approved by the EU and US regulatory agencies on or after January 01, 2014. Interested researchers can use www.vivli.org to request access to anonymized patient-level data and supporting documents from clinical studies to conduct research. Information on the Bayer criteria for listing studies and other relevant information is provided in the member section of the portal.

Questions about this trial

What is this clinical trial studying?

An observational study of Estrogen Therapy, run by Bayer at 2 sites in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 19 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Proportion of patients receiving estrogen therapy (time frame: Retrospective analysis from January 2025 to December 2025). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Oct 2026.

Free account

Keep searching with a free account

You’ve used your 3 free searches for this session. Log in or create a free AzTrials account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in