There is limited and contradictory evidence on the association of smoking status with adverse outcomes of severe acute respiratory syndrome coronavirus 2 infection.13 Furthermore, current smoking status does not encompass the cumulative effect of smoking. To our knowledge, no studies have assessed the cumulative effect of smoking over time, as measured by pack-years, though a single study of coronavirus disease 2019 (COVID-19) in a small cohort of 102 patients with lung cancer found that the patients with severe outcomes had a higher average pack-year history (30 vs 20 years).4 We hypothesize that there is an adverse association of cumulative smoking exposure, as measured by pack-years, with outcomes of patients with COVID-19.


Challiyil Eswaramangalath Vipin from Chalakudy, India [CC BY-SA 2.0 (], via Wikimedia Commons