Incidence of Symptoms Associated with Post-Acute Sequelae of SARS-CoV-2 infection in Non-Hospitalized Vaccinated Patients Receiving Nirmatrelvir-Ritonavir

TriNetX retrospective 1,004 paxlovid patients and matched controls, showing lower risk of PASC with treatment.Confounding by treatment propensity. This study analyzes a population where only a fraction of eligible patients received the treatment. Patients receiving treatment may be more likely to follow other recommendations, more likely to receive additional care, and more likely to receive adjuvant treatments that are not tracked in the data (e.g., nasal/oral hygiene [c19early.org, c19early.org (B)], vitamin D [c19early.org (C)], etc.) — either because the physician recommending paxlovid also recommended them, or because the patient seeking out paxlovid is more likely to be familiar with the efficacy of additional treatments. Therefore, these kind of studies may overestimate the efficacy of treatments. Confounding by contraindication. [Hoertel] find that over 50% of patients that died had a contraindication for the use of Paxlovid. Retrospective studies that do not exclude contraindicated patients may significantly overestimate efficacy.