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

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.