Reconsidering Long-Term Respiratory Risk After Severe COVID-19

We read with interest the recent study examining the association between prior SARS-CoV-2 infection and outcomes of subsequent acute respiratory hospitalizations. The findings suggesting that previous ICU-treated COVID-19 independently predicts adverse outcomes, while ward-treated infection appears protective, raise important clinical and methodological considerations. In this letter, we provide constructive reflections on potential residual confounding, regression modeling strategy, composite endpoint interpretation, and temporal heterogeneity related to pandemic waves. We further discuss the implications of incorporating prior COVID-19 severity into contemporary emergency department risk stratification frameworks. We argue that, if validated prospectively, history of severe COVID-19 may function as a long-term vulnerability marker in acute respiratory admissions. Continued prospective, multicenter investigations with standardized pulmonary and functional assessment are warranted to clarify the causal pathways underlying these observations.