We read with great interest the meta-analysis by Ambrosino and colleagues evaluating fractional exhaled nitric oxide (FeNO) in acute exacerbations of chronic obstructive pulmonary disease (AECOPD) [1]. This work is both timely and clinically relevant, providing a rigorous synthesis of a heterogeneous body of evidence and offering a valuable framework for assessing whether FeNO can meaningfully inform exacerbation evaluation and post-exacerbation monitoring. The authors’ application of multilevel modeling and comprehensive sensitivity analyses strengthens confidence in the robustness of the observed population-level signal.
