Atrial FibrillationNCT05256797
Prediction of the COBRRA AF Anticoagulant Trial in Healthcare Claims Data
An observational study of Atrial Fibrillation, run by Brigham and Women's Hospital at 1 site in United States.
Trial summary
Investigators are building an empirical evidence base for real world data through large-scale replication of randomized controlled trials. The investigators' goal is to understand for what types of clinical questions real world data analyses can be conducted with confidence and how to implement such studies. Read more about this study
- Who is it for?
- Ages 18 to 120 years
- Conditions the study is for
- Atrial Fibrillation
- What is being tested?
- Rivaroxaban and Apixaban
- How many people
- 353,980 participants
- Where
- 1 siteUnited States
- Study dates
- 3 May 2021to 15 Jun 2022
- Phase
- Observational
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 18 to 120 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: This study will involve a new user, parallel group, propensity score-matched, retrospective cohort study design comparing rivaroxaban to apixaban users. The patients will be required to have continuous enrollment during a baseline period of 180 days before initiation of rivaroxaban or apixaban (index date). Analysis is restricted to patients with non-valvular atrial fibrillation.
Who may be able to join
- At least 18 years of age
- Non-valvular atrial fibrillation
Who cannot join
- Prior anticoagulant use [Day -180, Day 0]
- Stage 4 or 5 chronic kidney disease or end-stage renal disease [Day -180, Day 0]
- Dialysis or renal transplant [Day -180, Day 0]
- Recent major or clinically relevant non-major bleeding [Day -180, Day 0]
- Other indications for anticoagulation (DVT, PE, or prosthetic heart valve) [Day -180, Day 0]
- Use of an antiplatelet [Day -180, Day 0]
Show all 12Show fewer
- Significant liver disease and coagulopathy [Day -180, Day 0]
- Use of CYP3A4 or P-gp inhibitors or inducers [Day -180, Day 0]
- Pregnancy or breastfeeding [Day -180, Day 0]
- Cancer [Day -180, Day 0]
- Bypass surgery, obesity, or the use of a weight loss or appetite suppressor [Day -180, Day 0]
- Mitral stenosis with or without insufficiency, mitral rheumatic insufficiency, and other/unspecified mitral valve disorders [Day -180, Day 0]
Trial locations and contacts
1 site in 1 country.
United States1 site
Brigham and Women's Hospital
Boston, Massachusetts, 02120
About this study
Investigators are building an empirical evidence base for real world data through large-scale replication of randomized controlled trials. The investigators' goal is to understand for what types of clinical questions real world data analyses can be conducted with confidence and how to implement such studies.
Read the detailed description
This is a non-randomized, non-interventional study that is part of the RCT DUPLICATE initiative (www.rctduplicate.org) of the Brigham and Women's Hospital, Harvard Medical School. It is intended to replicate, as closely as possible in healthcare insurance claims data, the trial listed below/above. Although many features of the trial cannot be directly replicated in healthcare claims, key design features, including outcomes, exposures, and inclusion/exclusion criteria, were selected to proxy those features from the trial. Randomization is also not replicable in healthcare claims data but was proxied through a statistical balancing of measured covariates through standard practice. Investigators assume that the RCT provides the reference standard treatment effect estimate and that failure to replicate RCT findings is indicative of the inadequacy of the healthcare claims data for replication for a range of possible reasons and does not provide information on the validity of the original RCT finding.
- Conditions
- Atrial Fibrillation
- Being tested
- Rivaroxaban, Apixaban
- Medical subject headings
- Atrial Fibrillation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
RivaroxabanDrug
Also called Xarelto
Any rivaroxaban dispensing claim is used as the reference group
ApixabanDrug
Also called Eliquis
Any apixaban dispensing claim is used as the exposure group
| Study group | Role | What they receive |
|---|---|---|
| Rivaroxaban | Reference group Receives: Drug: Rivaroxaban | |
| Apixaban | Exposure group Receives: Drug: Apixaban |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of Major Bleeding or Clinically Relevant Non-major Bleeding Events
Claims-based algorithm: incidence of major bleeding or clinically relevant non-major bleeding events
Measured: Through study completion or censoring, up to 365 days
Secondary outcomes (6)
Incidence of Major Bleeding
Claims-based algorithm: Incidence of major bleeding
Measured: Through study completion or censoring, up to 365 days
Incidence of Clinically Relevant Non-major Bleeding
Claims-based algorithm: Incidence of clinically relevant non-major bleeding
Measured: Through study completion or censoring, up to 365 days
Incidence of All-cause Mortality
Claims-based algorithm: Incidence of all-cause mortality
Measured: Through study completion or censoring, up to 365 days
Incidence of Stroke
Claims-based algorithm: Incidence of stroke
Measured: Through study completion or censoring, up to 365 days
Incidence of Extracranial Bleeding
Claims-based algorithm: Incidence of extracranial bleeding (any position)
Measured: Through study completion or censoring, up to 365 days
Incidence of Intracranial Bleeding
Claims-based algorithm: Incidence of intracranial bleeding (any position)
Measured: Through study completion or censoring, up to 365 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Feb 2022
- Study start3 May 2021
- Primary completion15 Jun 2022
- Study completion15 Jun 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Atrial FibrillationStudies of the same condition, open and under way.
- More trials run by Brigham and Women's HospitalThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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
- 353,980 participants (actual)
Sponsor and investigators
- Lead sponsor
- Brigham and Women's Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Shirley Vichy Wang, Brigham and Women's Hospital
- Investigators
- Shirley Wang, PhD, ScM, Principal investigator, Brigham and Women's Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05256797
- Sponsor's protocol ID
- 2018P002966-DUP-COBRRA-AF
- Status last verified
- Feb 2025
- First submitted
- 16 Feb 2022
- Last updated
- 4 Mar 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Publications
Mahesri M, Schneeweiss S, Lin KJ, Zabotka L, Concato J, Bradley MC, Wang SV. Bleeding Risk With Apixaban Versus Rivaroxaban: A Reference Trial Emulation Predicting the Results of COBRRA-VTE and COBRRA-AF Using US Health Care Claims. Circ Popul Health Outcomes. 2026 Jul;19(7):e012892. doi: 10.1161/CIRCOUTCOMES.125.012892. Epub 2026 Jul 2.
PubMed 42389777
Study at a glance
From the registry record, last updated by the sponsor on 4 Mar 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Prediction of the COBRRA AF Anticoagulant Trial in Healthcare Claims Data
- ClinicalTrials.gov ID
- NCT05256797
- Acronym / sponsor ID
- 2018P002966-DUP-COBRRA-AF
- Conditions
- Atrial Fibrillation
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 353,980 participants (actual)
- Lead sponsor
- Brigham and Women's HospitalUniversity, hospital or other
- Study start
- 3 May 2021 (actual)
- Primary completion
- 15 Jun 2022 (actual)
- Study completion
- 15 Jun 2022 (actual)
- First posted
- 25 Feb 2022 (actual)
- Results
- Posted 4 Mar 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Investigators are building an empirical evidence base for real world data through large-scale replication of randomized controlled trials. The investigators' goal is to understand for what types of clinical questions real world data analyses can be conducted with confidence and how to implement such studies.
Detailed description
This is a non-randomized, non-interventional study that is part of the RCT DUPLICATE initiative (www.rctduplicate.org) of the Brigham and Women's Hospital, Harvard Medical School. It is intended to replicate, as closely as possible in healthcare insurance claims data, the trial listed below/above. Although many features of the trial cannot be directly replicated in healthcare claims, key design features, including outcomes, exposures, and inclusion/exclusion criteria, were selected to proxy those features from the trial. Randomization is also not replicable in healthcare claims data but was proxied through a statistical balancing of measured covariates through standard practice. Investigators assume that the RCT provides the reference standard treatment effect estimate and that failure to replicate RCT findings is indicative of the inadequacy of the healthcare claims data for replication for a range of possible reasons and does not provide information on the validity of the original RCT finding.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Rivaroxaban | – | Drug: RivaroxabanReference group |
| Apixaban | – | Drug: ApixabanExposure group |
Who may qualify
- Ages
- 18 to 120 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- This study will involve a new user, parallel group, propensity score-matched, retrospective cohort study design comparing rivaroxaban to apixaban users. The patients will be required to have continuous enrollment during a baseline period of 180 days before initiation of rivaroxaban or apixaban (index date). Analysis is restricted to patients with non-valvular atrial fibrillation.
Key inclusion criteria (2 listed)
- At least 18 years of age
- Non-valvular atrial fibrillation
Key exclusion criteria (12 listed)
- Prior anticoagulant use [Day -180, Day 0]
- Stage 4 or 5 chronic kidney disease or end-stage renal disease [Day -180, Day 0]
- Dialysis or renal transplant [Day -180, Day 0]
- Recent major or clinically relevant non-major bleeding [Day -180, Day 0]
- Other indications for anticoagulation (DVT, PE, or prosthetic heart valve) [Day -180, Day 0]
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| RivaroxabanAlso: XareltoAny rivaroxaban dispensing claim is used as the reference group | Drug | Rivaroxaban |
| ApixabanAlso: EliquisAny apixaban dispensing claim is used as the exposure group | Drug | Apixaban |
Primary outcome
Incidence of Major Bleeding or Clinically Relevant Non-major Bleeding Events
Time frame: Through study completion or censoring, up to 365 days
Claims-based algorithm: incidence of major bleeding or clinically relevant non-major bleeding events
6 secondary outcomes
Incidence of Major Bleeding
Time frame: Through study completion or censoring, up to 365 days
Incidence of Clinically Relevant Non-major Bleeding
Time frame: Through study completion or censoring, up to 365 days
Incidence of All-cause Mortality
Time frame: Through study completion or censoring, up to 365 days
Incidence of Stroke
Time frame: Through study completion or censoring, up to 365 days
Incidence of Extracranial Bleeding
Time frame: Through study completion or censoring, up to 365 days
Incidence of Intracranial Bleeding
Time frame: Through study completion or censoring, up to 365 days
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Mar 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Derived from this study: PubMed 42389777Mahesri M, Schneeweiss S, Lin KJ, Zabotka L, Concato J, Bradley MC, Wang SV. Bleeding Risk With Apixaban Versus Rivaroxaban: A Reference Trial Emulation Predicting the Results of COBRRA-VTE and COBRRA-AF Using US Health Care Claims. Circ Popul Health Outcomes. 2026 Jul;19(7):e012892. doi: 10.1161/CIRCOUTCOMES.125.012892. Epub 2026 Jul 2.
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Atrial Fibrillation (AF)
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Shirley Wang, PhD, ScM principal investigator
Brigham and Women's Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Atrial Fibrillation, run by Brigham and Women's Hospital at 1 site 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 2 inclusion and 12 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: finished, as of the sponsor's last update on 4 Mar 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site 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?
Yes. Results are posted in the registry (first posted 4 Mar 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
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?
Incidence of Major Bleeding or Clinically Relevant Non-major Bleeding Events (time frame: Through study completion or censoring, up to 365 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05256797, which also lists 1 linked publication.
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 4 Mar 2025.