Effect of smoking on coronavirus disease susceptibility: A case-control study

Introduction: Tobacco use has changed since the onset of the coronavirus disease (COVID-19) pandemic. The effect of smoking on COVID-19 susceptibility has not yet been determined. In this study, we aimed to assess the association between smoking and COVID-19 susceptibility.

Methods: This retrospective case-control study was conducted at the quarantine center of Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia, between April and June 2020. A total of 142 adults participated in the study, 73 of whom tested positive for COVID-19 and were matched for both sex and age with participants in the control group. Telephone interviews were conducted to assess the risk factors associated with that exposure.

Results: Different variables are investigated for their impact on COVID-19 infection susceptibility. The current study's findings indicated that smokers comprised only 27.5% (n=39) of the participants. There was no association between the COVID-19 swab results and smoking status (χ²=1.857; p=0.395). Furthermore, there was no significant association between any of the smoking parameters and susceptibility to COVID-19, except for the smoking period (t= -2.105, p=0.041). The odds of having a positive swab result among cigarette smokers were lower than those among pipe, waterpipe, and electronic cigarette smokers (OR=0.600; p=0.394). An association was also observed between COVID-19-positive swab results and contact with an individual with COVID-19 or respiratory disease (χ²=79.270 and χ²=18.929, respectively, p≤0.001).

Conclusions: This study revealed no association between smoking status and COVID-19 swab test results. Further research with a bigger sample size is suggested to confirm the relationship between smoking and COVID-19 susceptibility.