Treatment Patterns Among Patients With Venous Thromboembolism in the United States

Post-Discharge Treatment Patterns and Outcomes in Patients With Venous Thromboembolism

The purpose of this study is to assess outpatient treatment patterns following hospitalization for venous thromboembolism (VTE). VTE is a condition that occurs when blood clot forms in the vein.

This is a retrospective study (assessments on events that have already occurred) of healthcare claims from databases. The study sponsors will assess healthcare claim records of patients treated with either apixaban or warfarin. Assessment includes treatment persistence, switch, and stopping therapy, along with recurrent VTE and bleeding.

Study Overview

• Status: Completed
• Conditions: Venous Thromboembolism
• Intervention / Treatment: Drug: apixaban; Drug: warfarin

• Study Type: Observational
• Enrollment (Actual): 13945

Contacts and Locations

Study Locations

• United States
  • New York
    • New York, New York, United States, 10017
      • Pfizer

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients who are hospitalized for venous thromboembolism (VTE) and treated with apixaban or warfarin during the hospitalization. Patients will be identified through linkage of IQVIA's hospital charge data master database (CDM) with outpatient professional fee medical claims (Dx) and longitudinal prescription claims (LRx) databases during the period of July 2018 and August 2022.

Description

Inclusion Criteria:

• inpatient hospitalization with primary discharge diagnosis of venous thromboembolism (VTE) (this is the index hospitalization)
• treatment with apixaban or warfarin during the hospitalization
• at least 18 years of age

Exclusion Criteria:

• Hospitalization for VTE within 6 months prior to the index hospitalization
• Diagnosis of atrial fibrillation/flutter or procedure for mechanical heart valve in the 6 months prior to the index hospitalization
• Procedure for inferior vena cava filter or diagnosis of pregnancy during the study period
• Prior use of oral anticoagulants or parenteral anticoagulants

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
apixaban; Patients treated with apixaban	Drug: apixaban; patients treated with apixaban
warfarin; patients treated with warfarin	Drug: warfarin; patients treated with warfarin

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants Who Continued Treatment With Apixaban or Warfarin Following Discharge From the Hospital	Following discharge from inpatient hospitalization, participants who continued apixaban or warfarin, respectively, in the outpatient setting (with outpatient treatment claim occurring on or within 30-days following the hospital discharge date) were identified.	From hospital discharge date through 30 days following discharge date (from the data retrieved for 5.5 years and retrospective data evaluated in approximately 7 months of this study)
Mean Number of Persistent Days	Persistent days was defined as the number of days from the index date until the first of the following: treatment discontinuation, treatment switch, or the end of follow-up. Treatment index date: date of first outpatient apixaban or warfarin claim.	From the index date until the first of treatment discontinuation, treatment switch, or the end of follow-up, whichever occurred first (data retrieved for 5.5 years and retrospective data evaluated in approximately 7 months of this study)
Percentage of Participants Who Discontinued Index Treatment at 6 Months Post-Discharge Index Date	Discontinuation was defined as greater than or equal to (>=) 30-day gap from the run-out of days supply of the treatment (post-discharge) index prescription (that is, apixaban or warfarin) to date of next claim for the respective therapy or with no other claims for the respective therapy. The date of discontinuation was last day of day's supply of the last filled prescription. Treatment index date: date of first outpatient apixaban or warfarin claim.	At 6 Months post-discharge index date (data retrieved for 5.5 years and retrospective data evaluated in approximately 7 months of this study)
Percentage of Participants Who Discontinued Index Treatment at 12 Months Post-Discharge Index Date	Discontinuation was defined as >= 30-day gap from the run-out of days supply of the treatment (post-discharge) index prescription (that is, apixaban or warfarin) to date of next claim for the respective therapy or with no other claims for the respective therapy. The date of discontinuation was last day of day's supply of the last filled prescription. Treatment index date: date of first outpatient apixaban or warfarin claim.	At 12 Months post-discharge index date (data retrieved for 5.5 years and retrospective data evaluated in approximately 7 months of this study)
Percentage of Participants Who Switched From Index Treatment at 6 Months Post-Discharge Index Date	Participants were considered to have switched if they filled a prescription for oral anticoagulant (OAC) other than apixaban or warfarin, respectively (identified through national drug codes [NDC] codes in longitudinal prescription claims [LRx]) or for parenteral anticoagulant (PAC) within 30 days before or after the run-out date of index treatment. The date of the switch was defined as date of the prescription of such a therapy (OAC or PAC). Treatment index date: date of first outpatient apixaban or warfarin claim.	At 6 Months post-discharge index date (data retrieved for 5.5 years and retrospective data evaluated in approximately 7 months of this study)
Percentage of Participants Who Switched From Index Treatment at Month 12 Post-Discharge Index Date	Participants were considered to have switched if they filled a prescription for OAC other than apixaban or warfarin, respectively (identified through NDC codes in LRx) or for PAC within 30 days before or after the run-out date of index treatment. The date of the switch was defined as date of the prescription of such a therapy (OAC or PAC). Treatment index date: date of first outpatient apixaban or warfarin claim.	At 12 Months post-discharge index date (data retrieved for 5.5 years and retrospective data evaluated in approximately 7 months of this study)
Median Time to Discontinuation From the Index Treatment	Time from treatment index date to discontinuation date was described in this outcome measure. Discontinuation was defined as >= 30-day gap from the run-out of days supply of the treatment (post-discharge) index prescription (that is, apixaban or warfarin) to date of next claim for the respective therapy or with no other claims for the respective therapy. The date of discontinuation was last day of day's supply of the last filled prescription. Treatment index date: date of first outpatient apixaban or warfarin claim.	From initiation of index treatment post-discharge till its discontinuation (data retrieved for 5.5 years and retrospective data evaluated in approximately 7 months of this study)
Median Time to Switch From the Index Treatment	Time from treatment index date to treatment switch date was described in this outcome measure. Participants were considered to have switched if they filled a prescription for OAC other than apixaban or warfarin, respectively (identified through NDC codes in LRx) or for PAC within 30 days before or after the run-out date of index treatment. The date of the switch was defined as date of the prescription of such a therapy (OAC or PAC). Treatment index date: date of first outpatient apixaban or warfarin claim.	From initiation of index treatment post-discharge till switch (data retrieved for 5.5 years and retrospective data evaluated in approximately 7 months of this study)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence Rate of Recurrent VTE Events	Recurrent VTE was defined as inpatient hospitalization with a primary diagnosis of VTE occurring 7 or more days after the first hospitalization discharge date. The date of the first observed event was flagged. Incidence rate was defined as the number of events (recurrent VTE) per 100 participant years. Treatment index date: date of first outpatient apixaban or warfarin claim.	From first hospitalization discharge date to subsequent inpatient hospitalization for VTE (data retrieved for 5.5 years and retrospective data evaluated in approximately 7 months of this study)
Median Time to Recurrent VTE	Recurrent VTE was defined as inpatient hospitalization with a primary diagnosis of VTE occurring 7 or more days after the first hospitalization discharge date. The date of the first observed event was flagged. Treatment index date: date of first outpatient apixaban or warfarin claim.	From first hospitalization discharge date to subsequent inpatient hospitalization for VTE (data retrieved for 5.5 years and retrospective data evaluated in approximately 7 months of this study)
Incidence Rate of Major Bleeding Events	Major bleeding was defined as inpatient hospitalization with primary diagnosis of gastro-intestinal bleeding, intracranial hemorrhage (ICH) or other major bleeding. Incidence rate was defined as the number of events (major bleeding) per 100 participant years. Treatment index date: date of first outpatient apixaban or warfarin claim.	From first hospitalization discharge through first major bleeding event (data retrieved for 5.5 years and retrospective data evaluated in approximately 7 months of this study)
Incidence Rate of Clinically Relevant Non-Major (CRNM) Bleeding Events	CRNM bleeding was defined as inpatient hospitalization with a secondary diagnosis code for bleeding (without a major bleeding code in the primary position) or an outpatient encounter with a diagnosis code in any position for CRNM gastrointestinal (GI) bleeding or other non-critical types of bleeding. Incidence rate was defined as the number of events (CRNM bleeding) per 100 participant years.	From first hospitalization discharge through first CRNM bleeding event (data retrieved for 5.5 years and retrospective data evaluated in approximately 7 months of this study)

Collaborators and Investigators

• Sponsor: Pfizer
• Collaborators: Bristol-Myers Squibb
• Investigators: Study Director: Pfizer CT.gov Call Center, Pfizer

Publications and helpful links

Helpful Links

• To obtain contact information for a study center near you, click here.

Study record dates

Study Major Dates

• Study Start (Actual): March 10, 2023
• Primary Completion (Actual): September 30, 2023
• Study Completion (Actual): September 30, 2023

Study Registration Dates

• First Submitted: March 6, 2023
• First Submitted That Met QC Criteria: March 29, 2023
• First Posted (Actual): April 3, 2023

Study Record Updates

• Last Update Posted (Estimated): November 22, 2024
• Last Update Submitted That Met QC Criteria: September 27, 2024
• Last Verified: September 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Embolism and Thrombosis; Thromboembolism; Venous Thromboembolism; Molecular Mechanisms of Pharmacological Action; Protease Inhibitors; Enzyme Inhibitors; Anticoagulants; Factor Xa Inhibitors; Antithrombins; Serine Proteinase Inhibitors; Apixaban; Warfarin
• Other Study ID Numbers: B0661190

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.