Does misclassification of former tobacco smokers explain the ‘smoker’s paradox’ in the risk of COVID-19? Insights from the Stockholm Public Health Cohort

BACKGROUND: The association between tobacco smoking and the risk of COVID-19 and its adverse outcomes is controversial, as studies reported contrasting findings. Bias due to misclassification of the exposure in the analyses of current versus non-current smoking could be a possible explanation becaus...

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Autores principales: Shaaban, Ahmed N., Andersson, Filip, Magnusson, Cecilia, Orsini, Nicola, Caspersen, Ida H., Peña, Sebastian, Karvonen, Sakari, Magnus, Per, Galanti, Maria R.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: SAGE Publications 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10183343/
https://www.ncbi.nlm.nih.gov/pubmed/37165603
http://dx.doi.org/10.1177/14034948231174279
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author Shaaban, Ahmed N.
Andersson, Filip
Magnusson, Cecilia
Orsini, Nicola
Caspersen, Ida H.
Peña, Sebastian
Karvonen, Sakari
Magnus, Per
Galanti, Maria R.
author_facet Shaaban, Ahmed N.
Andersson, Filip
Magnusson, Cecilia
Orsini, Nicola
Caspersen, Ida H.
Peña, Sebastian
Karvonen, Sakari
Magnus, Per
Galanti, Maria R.
author_sort Shaaban, Ahmed N.
collection PubMed
description BACKGROUND: The association between tobacco smoking and the risk of COVID-19 and its adverse outcomes is controversial, as studies reported contrasting findings. Bias due to misclassification of the exposure in the analyses of current versus non-current smoking could be a possible explanation because former smokers may have higher background risks of the disease due to co-morbidity. The aim of the study was to investigate the extent of this potential bias by separating non-, former, and current smokers when assessing the risk or prognosis of diseases. METHODS: We analysed data from 43,400 participants in the Stockholm Public Health Cohort, Sweden, with information on smoking obtained prior to the pandemic. We estimated the risk of COVID-19, hospital admissions and death for (a) former and current smokers relative to non-smokers, (b) current smokers relative to non-current smokers, that is, including former smokers; adjusting for potential confounders (aRR). RESULTS: The aRR of a COVID-19 diagnosis was elevated for former smokers compared with non-smokers (1.07; 95% confidence interval (CI) =1.00–1.15); including hospital admission with any COVID-19 diagnosis (aRR= 1.23; 95% CI = 1.03–1.48); or with COVID-19 as the main diagnosis (aRR=1.23, 95% CI= 1.01–1.49); and death within 30 days with COVID-19 as the main or a contributory cause (aRR=1.40; 95% CI=1.00–1.95). Current smoking was negatively associated with risk of COVID-19 (aRR=0.79; 95% CI=0.68–0.91). CONCLUSIONS: Separating non-smokers from former smokers when assessing the disease risk or prognosis is essential to avoid bias. However, the negative association between current smoking and the risk of COVID-19 could not be entirely explained by misclassification.
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spelling pubmed-101833432023-05-15 Does misclassification of former tobacco smokers explain the ‘smoker’s paradox’ in the risk of COVID-19? Insights from the Stockholm Public Health Cohort Shaaban, Ahmed N. Andersson, Filip Magnusson, Cecilia Orsini, Nicola Caspersen, Ida H. Peña, Sebastian Karvonen, Sakari Magnus, Per Galanti, Maria R. Scand J Public Health Original Articles BACKGROUND: The association between tobacco smoking and the risk of COVID-19 and its adverse outcomes is controversial, as studies reported contrasting findings. Bias due to misclassification of the exposure in the analyses of current versus non-current smoking could be a possible explanation because former smokers may have higher background risks of the disease due to co-morbidity. The aim of the study was to investigate the extent of this potential bias by separating non-, former, and current smokers when assessing the risk or prognosis of diseases. METHODS: We analysed data from 43,400 participants in the Stockholm Public Health Cohort, Sweden, with information on smoking obtained prior to the pandemic. We estimated the risk of COVID-19, hospital admissions and death for (a) former and current smokers relative to non-smokers, (b) current smokers relative to non-current smokers, that is, including former smokers; adjusting for potential confounders (aRR). RESULTS: The aRR of a COVID-19 diagnosis was elevated for former smokers compared with non-smokers (1.07; 95% confidence interval (CI) =1.00–1.15); including hospital admission with any COVID-19 diagnosis (aRR= 1.23; 95% CI = 1.03–1.48); or with COVID-19 as the main diagnosis (aRR=1.23, 95% CI= 1.01–1.49); and death within 30 days with COVID-19 as the main or a contributory cause (aRR=1.40; 95% CI=1.00–1.95). Current smoking was negatively associated with risk of COVID-19 (aRR=0.79; 95% CI=0.68–0.91). CONCLUSIONS: Separating non-smokers from former smokers when assessing the disease risk or prognosis is essential to avoid bias. However, the negative association between current smoking and the risk of COVID-19 could not be entirely explained by misclassification. SAGE Publications 2023-05-10 2023-07 /pmc/articles/PMC10183343/ /pubmed/37165603 http://dx.doi.org/10.1177/14034948231174279 Text en © Author(s) 2023 https://creativecommons.org/licenses/by/4.0/This article is distributed under the terms of the Creative Commons Attribution 4.0 License (https://creativecommons.org/licenses/by/4.0/) which permits any use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage).
spellingShingle Original Articles
Shaaban, Ahmed N.
Andersson, Filip
Magnusson, Cecilia
Orsini, Nicola
Caspersen, Ida H.
Peña, Sebastian
Karvonen, Sakari
Magnus, Per
Galanti, Maria R.
Does misclassification of former tobacco smokers explain the ‘smoker’s paradox’ in the risk of COVID-19? Insights from the Stockholm Public Health Cohort
title Does misclassification of former tobacco smokers explain the ‘smoker’s paradox’ in the risk of COVID-19? Insights from the Stockholm Public Health Cohort
title_full Does misclassification of former tobacco smokers explain the ‘smoker’s paradox’ in the risk of COVID-19? Insights from the Stockholm Public Health Cohort
title_fullStr Does misclassification of former tobacco smokers explain the ‘smoker’s paradox’ in the risk of COVID-19? Insights from the Stockholm Public Health Cohort
title_full_unstemmed Does misclassification of former tobacco smokers explain the ‘smoker’s paradox’ in the risk of COVID-19? Insights from the Stockholm Public Health Cohort
title_short Does misclassification of former tobacco smokers explain the ‘smoker’s paradox’ in the risk of COVID-19? Insights from the Stockholm Public Health Cohort
title_sort does misclassification of former tobacco smokers explain the ‘smoker’s paradox’ in the risk of covid-19? insights from the stockholm public health cohort
topic Original Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10183343/
https://www.ncbi.nlm.nih.gov/pubmed/37165603
http://dx.doi.org/10.1177/14034948231174279
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