Time to antiviral treatment in mild-moderate COVID-19 in the emergency department: influence of prescribing physician and effect on outcomes.

The primary objective is to know how the time from symptom onset to antiviral administration (total time, TT) affects hospitalisation and death from any cause at 30 days (composite endpoint) in patients with mild-to-moderate COVID-19 discharged from the emergency department (ED). Secondary objectives are to know how the time from ED admission to antiviral administration (hospital time, HT) modifies outcomes and whether the specialty of the prescribing physician influences these times. We conducted a nationwide, multicentre, retrospective cohort study in 16 Spanish EDs. We collected data from patients with mild-to-moderate COVID-19 who presented to an ED, received antiviral treatment, and were at risk of disease progression due to advanced age, comorbidities, or immunosuppression. We developed pooled logistic regression explanatory models to assess the association between TT, HT, and composite outcome, whilst we used quantile regression explanatory models to analyse the association between prescriber specialty and these times. All models were adjusted for confounding using inverse probability weighting. We analysed data on 534 treated patients. Longer TT was associated with worse outcomes, adjusted hazard ratio (aHR) 1,179 per day of delay, 95% confidence interval, 95% CI, 1,005 - 1,384; but no association was observed between HT and these events, aHR 1,312, 95% CI 0,900 - 1,913. Prescription by an emergency physician was associated with a reduction both in TT and in HT (adjusted median of reduction in hours, 6,78, 95% CI 0,21 - 20,65; 8,45, 95% CI 3,92 - 12,03, respectively). Earlier ED administration of antivirals for mild-to-moderate COVID-19 in vulnerable patients is associated with better clinical outcomes. Prescription by an emergency physician in the ED is also associated with shorter HT and TT.