Association of Smoking with COVID-19 Infection and Mortality

Pavankumar Kamat


June 11, 2021


  • Current and previous smokers aged <69 years had an increased risk of COVID-19 infection.

  • Older smokers aged ≥69 years were twice as likely to die from COVID-19 than never smokers, possibly because of the increased risk of chronic conditions/illnesses.

Why this matters

  • Findings suggest that current and past smoking history should be considered while assessing the risk of COVID-19 mortality in people aged ≥69 years.

Study design

  • This prospective study included 402,978 participants from the UK Biobank who were followed up from 1 February to 28 June 2020 using data from linked Hospital Episode Statistics.

  • Key outcome was risk of COVID-19 infection and subsequent mortality.

  • Funding: National Institute for Health Research Oxford Biomedical Research Centre.

Key results

  • Of 402,978 participants, 224,451 (55.7%) were non-smokers, 139,056 (34.5%) were previous smokers and 39,471 (9.8%) were current smokers.

  • During the study period, 1591 (0.39%) tested positive for COVID-19, of whom 372 (23.4%) died subsequently.

  • Current smokers aged <69 years vs non-smokers were almost twice as likely to become infected with SARS-CoV-2 (adjusted incidence risk ratios [aIRR], 1.88; 95% CI, 1.49-2.38), but no difference was seen in the risk in those aged ≥69 years (aIRR, 1.05; 95% CI, 0.82-1.34).

  • In contrast, current smokers aged ≥69 years vs non-smokers were twice as likely to die from COVID-19 (aIRR, 2.15; 95% CI, 1.11-4.16), but the association was less pronounced in those aged <69 years (aIRR, 1.22; 95% CI, 0.83-1.79).

  • Similar patterns were observed for previous smokers.


  • COVID-19 infection may be underestimated using laboratory-confirmed cases alone.s


Prats-Uribe A, Xie J, Prieto-Alhambra D, Petersen I. Smoking and COVID-19 Infection and Related Mortality: A Prospective Cohort Analysis of UK Biobank Data. Clin Epidemiol. 2021;13:357-365. doi: 10.2147/CLEP.S300597. PMID: 34079378.  View full text

This clinical summary originally appeared on Univadis, part of the Medscape Professional Network.


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