A Study to Understand How the Use of Paxlovid Affected Healthcare Use in People With Pre-existing Conditions.

July 21, 2025 updated by: Pfizer

Impact of Nirmatrelvir-ritonavir on Changes in Healthcare Utilization and Frailty Following COVID-19: a Difference-in-difference Analysis

This is a cohort study that will include Paxlovid (nirmatrelvir-ritonavir) treatment eligible for people with a positive SARS-CoV-2 diagnostic test and at least one COVID-19 symptom. This study will look at the change in Post Covid Conditions measured by the number of outpatients, Emergency department, urgent care and inpatient visits before and after COVID-19 between those who did and did not receive Paxlovid. In addition, changes in frailty post-acute infection will be evaluated, in a separate analysis. It is hypothesized that individuals with COVID-19 who received Paxlovid will have a smaller post-COVID-19 increase (vs pre-COVID) in PCC healthcare utilization (i.e., cardiopulmonary) in comparison to patients with COVID-19 who did not receive Paxlovid.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
14000

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • New York
      • New York, New York, United States, 10001
        • Pfizer New York

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Members of the Kaiser Permanente Southern California integrated healthcare delivery system.

Description

Inclusion Criteria:

  • Developed at least one COVID-19 symptom between Apr 1, 2022 through Dec 31, 2023
  • A positive lab-confirmed polymerase chain reaction (PCR) SARS-COV-2 test 5 days after symptom onset (primary analysis).
  • Continuous enrollment in KPSC health plans for at least 1 year (allowing for a 31-day gap to account for potential delays in membership renewal) before the date of symptom onset
  • Active membership in KPSC health plans for at least 31 days after the date of symptom onset
  • Eligible for nirmatrelvir-ritonavir defined by age and CDC-defined risk factors for severe COVID-19

Exclusion Criteria:

  • Individuals on another medication that is contraindicated for treatment with nirmatrelvir-ritonavir defined as having any prescription drug claim in the 90 days prior to COVID-19 symptom onset
  • Receipt of any COVID-19 antiviral (molnupiravir, remdesivir, nirmatrelvir/ritonavir) or monoclonal antibody treatment (bamlanivimab, bebtelovimab, casirivimab/imdevimab, cilgavimab/tixagevimab, otrovimab,) <180 days prior to COVID-19 symptom onset
  • Any positive SARS-CoV-2 test, including self-reported tests, <180 days prior to COVID-19 symptom onset.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Participants who received nirmatrelvir-ritonavir
Patients with cardio-pulmonary conditions
Drug: nirmatrelvir-ritonavir
Paxlovid standard of treatment care
Other Names:
  • Paxlovid
Participants who did not received nirmatrelvir-ritonavir
Patients with cardio-pulmonary conditions

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Cardio-pulmonary Measurement A: Change in rate of cardiopulmonary-related healthcare utilization in patients that received nirmatrelvir-ritonavir compared to not received.
Time Frame: 180 days before COVID-19 symptoms to 180 days after or 365 days after
180 days before COVID-19 symptoms to 180 days after or 365 days after

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Time Frame
Frailty Measurement A: Change in frailty measured by Frailty score Median (IQR) in patients that did receive in patients nirmatrelvir-ritonavir compared to not received.
Time Frame: During Pre-period: 12 months prior to symptom onset Frailty score Median (IQR) to 12 months after.
During Pre-period: 12 months prior to symptom onset Frailty score Median (IQR) to 12 months after.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Pfizer

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Pfizer CT.gov Call Center, Pfizer

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 15, 2025

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 15, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
April 15, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 21, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 21, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 29, 2025

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 29, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 21, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • C4671067

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.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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Dietary Supplements

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