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0 0.5 1 1.5 2+ Mortality 71% Improvement Relative Risk Death/hospitalization 44% Hospitalization 40% Paxlovid  Dryden-Peterson et al.  EARLY TREATMENT Is early treatment with paxlovid beneficial for COVID-19? Retrospective 44,045 patients in the USA (January - July 2022) Lower mortality (p=0.0064) and death/hosp. (p=0.0001) Dryden-Peterson et al., Annals of Inte.., Dec 2022 Favors paxlovid Favors control

Nirmatrelvir Plus Ritonavir for Early COVID-19 in a Large U.S. Health System

Dryden-Peterson et al., Annals of Internal Medicine, doi:10.7326/M22-2141 (date from preprint)
Dec 2022  
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IPW retrospective 44,551 outpatients age 50+ in the USA, showing lower mortality and hospitalization with paxlovid treatment.
Confounding by contraindication. Hoertel et al. find that over 50% of patients that died had a contraindication for the use of Paxlovid Hoertel. Retrospective studies that do not exclude contraindicated patients may significantly overestimate efficacy.
Black box warning. The FDA notes that "severe, life-threatening, and/or fatal adverse reactions due to drug interactions have been reported in patients treated with paxlovid" FDA.
risk of death, 71.0% lower, RR 0.29, p = 0.006, treatment 11,797, control 32,248, propensity score weighting.
risk of death/hospitalization, 44.0% lower, RR 0.56, p < 0.001, treatment 69 of 11,797 (0.6%), control 310 of 32,248 (1.0%), NNT 266, propensity score weighting.
risk of hospitalization, 40.0% lower, RR 0.60, p = 0.001, treatment 11,797, control 32,248, propensity score weighting.
Effect extraction follows pre-specified rules prioritizing more serious outcomes. Submit updates
Dryden-Peterson et al., 13 Dec 2022, retrospective, USA, peer-reviewed, 12 authors, study period 1 January, 2022 - 17 July, 2022.
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Nirmatrelvir Plus Ritonavir for Early COVID-19 in a Large U.S. Health System
MD, MSc Scott Dryden-Peterson, BS Andy Kim, MD Arthur Y Kim, ScD Ellen C Caniglia, MD, MPH, MBA Inga T Lennes, MD, MPH Rajesh Patel, RN Lindsay Gainer, RN Lisa Dutton, RN, MSN, NP-C Elizabeth Donahue, MD Rajesh T Gandhi, MD Lindsey R Baden, MD, MPH Ann E Woolley
Annals of Internal Medicine, doi:10.7326/m22-2141
Background: In the EPIC-HR (Evaluation of Protease Inhibition for Covid-19 in High-Risk Patients) trial, nirmatrelvir plus ritonavir led to an 89% reduction in hospitalization or death among unvaccinated outpatients with early COVID-19. The clinical impact of nirmatrelvir plus ritonavir among vaccinated populations is uncertain. Objective: To assess whether nirmatrelvir plus ritonavir reduces risk for hospitalization or death among outpatients with early COVID-19 in the setting of prevalent SARS-CoV-2 immunity and immune-evasive SARS-CoV-2 lineages. Design: Population-based cohort study analyzed to emulate a clinical trial using inverse probability-weighted models to account for anticipated bias in treatment. Setting: A large health care system providing care for 1.5 million patients in Massachusetts and New Hampshire during the Omicron wave (1 January to 17 July 2022). Patients: 44 551 nonhospitalized adults (90.3% with ≥3 vaccine doses) aged 50 years or older with COVID-19 and no contraindications for nirmatrelvir plus ritonavir. Measurements: The primary outcome was a composite of hospitalization within 14 days or death within 28 days of a COVID-19 diagnosis. Results: During the study period, 12 541 (28.1%) patients were prescribed nirmatrelvir plus ritonavir, and 32 010 (71.9%) were not. Patients prescribed nirmatrelvir plus ritonavir were more likely to be older, have more comorbidities, and be vaccinated. The composite outcome of hospitalization or death occurred in 69 (0.55%) patients who were prescribed nirmatrelvir plus ritonavir and 310 (0.97%) who were not (adjusted risk ratio, 0.56 [95% CI, 0.42 to 0.75]). Recipients of nirmatrelvir plus ritonavir had lower risk for hospitalization (adjusted risk ratio, 0.60 [CI, 0.44 to 0.81]) and death (adjusted risk ratio, 0.29 [CI, 0.12 to 0.71]). Limitation: Potential residual confounding due to differential access to COVID-19 vaccines, diagnostic tests, and treatment. Conclusion: The overall risk for hospitalization or death was already low (1%) after an outpatient diagnosis of COVID-19, but nirmatrelvir plus ritonavir reduced this risk further.
Author contributions are available at Previous Posting: This manuscript was posted as a preprint on medRxiv on 17 June 2022. doi:10.1101/2022.06. 14.22276393
Administrative, Kim, Lennes, Patel, Gainer et al., logistic support
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Dryden-Peterson, Kim, Caniglia, Patel, Dutton et al., ORIGINAL RESEARCH Nirmatrelvir Plus Ritonavir for Early COVID-19 in a Large U.S. Health System Author Contributions: Conception and design
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