2025
Effectiveness of the 2023-to-2024 XBB.1.5 COVID-19 Vaccines Over Long-Term Follow-up : A Target Trial Emulation.
Ioannou G, Berry K, Rajeevan N, Li Y, Yan L, Huang Y, Lin H, Bui D, Hynes D, Rowneki M, Bohnert A, Boyko E, Iwashyna T, Maciejewski M, Smith V, Berkowitz T, O'Hare A, Viglianti E, Aslan M, Bajema K. Effectiveness of the 2023-to-2024 XBB.1.5 COVID-19 Vaccines Over Long-Term Follow-up : A Target Trial Emulation. Annals Of Internal Medicine 2025, 178: 348-359. PMID: 39903865, DOI: 10.7326/annals-24-01015.Peer-Reviewed Original ResearchConceptsU.S. Department of Veterans AffairsDepartment of Veterans AffairsMatched index dateVaccine effectivenessTarget trial emulationSARS-CoV-2-associated deathsRandomized controlled trialsCOVID-19 vaccineSARS-CoV-2-related outcomesSARS-CoV-2 testingVeterans AffairsResidual confoundingAbsence of randomized controlled trialsLong-term follow-upDocumented SARS-CoV-2 infectionTrial emulationUnvaccinated personsIndex datePositive resultsControlled trialsCOVID-19SARS-CoV-2 infectionIncomplete captureHospitalDocumented infection
2024
Development of a prediction model for 30-day COVID-19 hospitalization and death in a national cohort of Veterans Health Administration patients–March 2022—April 2023
Bui D, Bajema K, Huang Y, Yan L, Li Y, Rajeevan N, Berry K, Rowneki M, Argraves S, Hynes D, Huang G, Aslan M, Ioannou G. Development of a prediction model for 30-day COVID-19 hospitalization and death in a national cohort of Veterans Health Administration patients–March 2022—April 2023. PLOS ONE 2024, 19: e0307235. PMID: 39365775, PMCID: PMC11451987, DOI: 10.1371/journal.pone.0307235.Peer-Reviewed Original ResearchConceptsVeterans Health AdministrationCOVID-19 hospitalizationArea under the receiver operating characteristic curveComprehensive electronic health recordNational cohortElectronic health recordsAll-cause mortalityNational cohort of patientsFull modelHealth recordsHealth AdministrationReceipt of COVID-19 vaccineMortality riskEpidemiology of COVID-19COVID-19High-risk patientsBrier scoreCohort of patientsAnti-SARS-CoV-2 treatmentCOVID-19 vaccineReceiver operating characteristic curveCalibration interceptHospitalAntiviral treatmentAvailability of effective vaccinesIdentifying Veterans Who Benefit From Nirmatrelvir-Ritonavir: A Target Trial Emulation
Yan L, Bui D, Li Y, Rajeevan N, Rowneki M, Berry K, Argraves S, Huang Y, Hynes D, Cunningham F, Huang G, Aslan M, Ioannou G, Bajema K. Identifying Veterans Who Benefit From Nirmatrelvir-Ritonavir: A Target Trial Emulation. Clinical Infectious Diseases 2024, 79: 643-651. PMID: 38864601, DOI: 10.1093/cid/ciae202.Peer-Reviewed Original ResearchRisk quartileVeterans Health AdministrationLowest risk quartileHighest risk quartileTarget trial emulationRisk prediction modelUntreated veteransRisk of deathOlder veteransYounger veteransHealth AdministrationTrial emulationMeasure incidenceNirmatrelvir-ritonavirVeteransHospitalUntreated participantsCOVID-19QuartileRiskSevere coronavirus disease 2019ParticipantsPersonsCoronavirus disease 2019Severe COVID-19
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