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Tobacco Use and COVID-19 Incidence in the Finnish General Population

Tobacco Use and Incidence of SARS-CoV-2 Infection in the Finnish General Population

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT04915781
Acronym
Tobrisk-CoV
Enrollment
60872
Registered
2021-06-07
Start date
2017-10-02
Completion date
2021-12-30
Last updated
2022-06-22

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Covid19, SARS-CoV-2 Infection

Keywords

Tobacco use, SARS-CoV-2, COVID-19, Epidemiology, Cohort Studies, Incidence

Brief summary

This is an observational study of participants in three general population health surveys (FinSote 2018, 2019, 2020) who are followed up until the incidence of SARS-CoV-2 infection or end of follow-up. The primary objective is to examine the association between tobacco use and the risk of SARS-CoV-2 infection in a general population sample in Finland.

Detailed description

Tobacco use, as a leading risk factor of death and disability due to respiratory diseases, was expected to increase the risk of SARS-CoV-2 infection and COVID-19 deaths. Earlier epidemiological studies, however, showed that smokers were underrepresented among patients hospitalized due to COVID-19. The most recent meta-analysis has confirmed these early findings, showing that current smokers had lower risk of SARS-CoV-2 infection than never smokers (Relative risk 0.71, 95% Credible interval 0.61; 0.82). A majority of these studies are based on samples of hospitalized patients, tested population or specific population groups, which might not represent the general population. In addition, data on tobacco use has been primarily collected from electronic health records or retrospectively and therefore prone to misclassification and information bias. A message of a protective effect of tobacco use could undermine public health efforts to curb its use and reduce the perception of harm in the general population. Studies with general population samples and prospective data collection are thus urgently needed. The aim of the study is to examine the association between tobacco use and the risk of SARS-CoV-2 infection. We will explore several forms of tobacco use (smoking, moist smokeless tobacco and e-cigarettes) and investigate whether introducing a potential collider bias by adjusting for mediating risk factors (alcohol use, physical activity and obesity) could have explained earlier results. We will use data from a prospective cohort study of nationally representative health surveys in Finland linked to SARS-CoV-2 incidence data, which is less subject to collider and recall bias than previous case-control studies.

Interventions

Not applicable, this is an observational study

Sponsors

Karolinska Institutet
CollaboratorOTHER
Norwegian Institute of Public Health
CollaboratorOTHER_GOV
Finnish Institute for Health and Welfare
Lead SponsorOTHER_GOV

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
20 Years to No maximum
Healthy volunteers
Yes

Inclusion criteria

* Permanent residents of Finland * Registered in the Population Register at the moment of sampling * Aged 20 and over * Participated in the FinSote surveys in 2018, 2019 or 2020

Exclusion criteria

* Temporary residents in Finland or tourists * Age less than 20 years old * Did not participate in FinSote surveys in 2018, 2019 and 2020

Design outcomes

Primary

MeasureTime frameDescription
Incidence of SARS-CoV-2 infectionBaseline until SARS-CoV-2 infection or April 30, 2021Incidence is the detection of a new SARS-CoV-2 infection with RT-PCR or a COVID-19 syndrome diagnosed by a physician from baseline to April 30, 2021

Countries

Finland

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026