Association of smoking status with outcomes in hospitalised patients with COVID-19.

Introduction: Smoking causes inflammation of the lung epithelium by releasing cytokines and impairing mucociliary clearance. Some studies have linked smoking with severity of illness of COVID-19 whereas others have found no such association.

Methods: This was a retrospective analysis of all adults hospitalised with COVID-19 from 9 March to 18 May 2020.