Practical Application of Remdesivir-Based Regimens in COVID-19: A Retrospective Case-Control Analysis

The SARS-CoV-2 pandemic strained global healthcare, creating a demand for effective inpatient treatments. Observational comparisons of remdesivir (RDV) versus non-RDV are subject to confounding by indication and temporal trends. This study assessed the real-world effectiveness of RDV-based regimens using propensity score matching (PSM).

We conducted a single-center retrospective cohort study at BouAli Hospital, analyzing 2,216 adults hospitalized with COVID-19 between March and September 2020. The propensity score for RDV receipt was estimated via logistic regression including age, admission SpO₂, comorbidities, vaccination status, adjunct therapies, and pandemic wave. Patients were matched 1:1 by nearest neighbor (caliper 0.2 SD, common support). Covariate balance was assessed using standardized mean differences (SMD). Outcomes included hospital mortality, ICU admission, intubation, and length of stay (LOS).

PSM produced 1,108 well-matched pairs (n=2,216). Some imbalance persisted (largest |SMD|: atorvastatin 0.35; vaccination 0.35; wave 0.24; age 0.17). RDV was associated with a lower intubation risk (OR 0.50, 95% CI 0.39-0.65; P<0.001) but not ICU admission (OR 0.89, 95% CI 0.72-1.09; P=0.286) or mortality (OR ≈1.0, ns). LOS was longer in RDV users (median +1.52 days; P<0.001). Doubly adjusted GEE models confirmed these findings (intubation OR 0.60, 95% CI 0.42-0.87; P=0.007; ICU OR 1.21, 95% CI 0.84-1.75; ns).

After PSM and adjustment, RDV use was linked to reduced intubation but not ICU admission or mortality, with longer hospital stays observed. Residual imbalance and unmeasured severity limit causal inference. Further studies are needed to guide personalized COVID-19 treatment.