COVID-19NCT07090486
A Study to Understand How the Use of Paxlovid Affected Healthcare Use in People With Pre-existing Conditions.
An observational study of COVID-19, run by Pfizer at 1 site in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- COVID-19
- What is being tested?
- nirmatrelvir-ritonavir
- How many people
- 14,000 participants
- Where
- 1 siteUnited States
- Study dates
- 15 Apr 2025to 15 Apr 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Members of the Kaiser Permanente Southern California integrated healthcare delivery system.
Who may be able to join
- 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
Who cannot join
- 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.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: 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.
- Conditions
- COVID-19
- Being tested
- nirmatrelvir-ritonavir
- Keywords
- Coronavirus-19 disease (COVID-19), Kaiser Permanente Southern California (KPSC), post-COVID conditions (PCC), Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), Long COVID, nirmatrelvir-ritonavir
- Medical subject headings
- COVID-19, Post-Acute COVID-19 Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
nirmatrelvir-ritonavirDrug
Also called Paxlovid
Paxlovid standard of treatment care
| Study group | Role | What they receive |
|---|---|---|
| Participants who received nirmatrelvir-ritonavir | Patients with cardio-pulmonary conditions Receives: Drug: nirmatrelvir-ritonavir | |
| Participants who did not received nirmatrelvir-ritonavir | Patients with cardio-pulmonary conditions |
What is being measured
The primary outcome is the main question the study is designed to answer.
Cardio-pulmonary Measurement A: Change in rate of cardiopulmonary-related healthcare utilization in patients that received nirmatrelvir-ritonavir compared to not received.
Measured: 180 days before COVID-19 symptoms to 180 days after or 365 days after
Secondary outcomes (1)
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.
Measured: During Pre-period: 12 months prior to symptom onset Frailty score Median (IQR) to 12 months after.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Jul 2025
- Study start15 Apr 2025
- Primary completion15 Apr 2025
- Study completion15 Apr 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for COVID-19Studies of the same condition, open and under way.
- More trials run by PfizerThe 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
- Other
- Time perspective
- Retrospective
- Enrolment
- 14,000 participants (actual)
Sponsor and investigators
- Lead sponsor
- Pfizer
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Pfizer CT.gov Call Center, Study director, Pfizer
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07090486
- Sponsor's protocol ID
- C4671067
- Status last verified
- Jul 2025
- First submitted
- 21 Jul 2025
- Last updated
- 29 Jul 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No: 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.
Study at a glance
From the registry record, last updated by the sponsor on 29 Jul 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Impact of Nirmatrelvir-ritonavir on Changes in Healthcare Utilization and Frailty Following COVID-19: a Difference-in-difference Analysis
- ClinicalTrials.gov ID
- NCT07090486
- Acronym / sponsor ID
- C4671067
- Conditions
- COVID-19
- Keywords
- Coronavirus-19 disease (COVID-19), Kaiser Permanente Southern California (KPSC), post-COVID conditions (PCC), Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), Long COVID, nirmatrelvir-ritonavir
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 14,000 participants (actual)
- Lead sponsor
- PfizerIndustry (pharma, biotech, devices)
- Study start
- 15 Apr 2025 (actual)
- Primary completion
- 15 Apr 2025 (actual)
- Study completion
- 15 Apr 2025 (actual)
- First posted
- 29 Jul 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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 design
- Observational model
- Other
- Time perspective
- Retrospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Participants who received nirmatrelvir-ritonavir | – | Drug: nirmatrelvir-ritonavirPatients with cardio-pulmonary conditions |
| Participants who did not received nirmatrelvir-ritonavir | – | –Patients with cardio-pulmonary conditions |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Members of the Kaiser Permanente Southern California integrated healthcare delivery system.
Key inclusion criteria (5 listed)
- 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
Key exclusion criteria (3 listed)
- 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.
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 |
|---|---|---|
| nirmatrelvir-ritonavirAlso: PaxlovidPaxlovid standard of treatment care | Drug | Participants who received nirmatrelvir-ritonavir |
Primary outcome
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
1 secondary outcome
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.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Jul 2025.
- To obtain contact information for a study center near you, click here.Link provided by the sponsor.
- Individual participant dataSharing planned: No. 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.
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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.
Pfizer CT.gov Call Center study director
Pfizer
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 COVID-19, run by Pfizer 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 5 inclusion and 3 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 29 Jul 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
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). 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 29 Jul 2025.