Tobacco Use and COVID-19 Incidence in the Finnish General Population (Tobrisk-CoV)

June 16, 2022 updated by: Finnish Institute for Health and Welfare

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

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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

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.

Study Type

Observational

Enrollment (Actual)

60872

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Finland
      • Helsinki, Finland, 00271
        • Finland

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

20 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Sampling Method

Probability Sample

Study Population

Permanent residents in Finland aged 20 and over who participated in the FinSote surveys in 2018, 2019 and 2020. These are general population samples representative of the Finnish population. The sampling frame was the Population Register (in 2020 the Digital and Population Data Services Agency, created after the merge between the Population Register of Statistics Finland and local register offices), which includes all individuals residing permanently in Finland, including conscripts and people living in institutions.

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Tobacco users
Never smokers (reference group) will be compared with former smokers, occasional smokers and daily smokers. For FinSote 2018 and 2020, we will also compare never users of (1) smokeless tobacco (snus), (2) electronic cigarettes with and without nicotine or (3) nicotine replacement therapy products with respective former, occasional and daily users.
Other: Not applicable, this is an observational study
Not applicable, this is an observational study

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of SARS-CoV-2 infection
Time Frame: Baseline until SARS-CoV-2 infection or April 30, 2021
Incidence 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
Baseline until SARS-CoV-2 infection or April 30, 2021

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Finnish Institute for Health and Welfare

Collaborators

Norwegian Institute of Public Health
Karolinska Institutet

Investigators

  • Principal Investigator: Sakari Karvonen, PhD, Finnish Institute for Health and Welfare

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

October 2, 2017

Primary Completion (Actual)

December 30, 2021

Study Completion (Actual)

December 30, 2021

Study Registration Dates

First Submitted

June 3, 2021

First Submitted That Met QC Criteria

June 4, 2021

First Posted (Actual)

June 7, 2021

Study Record Updates

Last Update Posted (Actual)

June 22, 2022

Last Update Submitted That Met QC Criteria

June 16, 2022

Last Verified

June 1, 2022

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • THL/713/6.00.00/2021

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Researchers can access individual data by contacting the Responsible Researcher at the Finnish Institute for Health and Welfare, Suvi Parikka, suvi.parikka [at] thl.fi.

Information about FinSote surveys, including questionnaires, can be found in https://thl.fi/fi/tutkimus-ja-kehittaminen/tutkimukset-ja-hankkeet/finsote-tutkimus

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Covid19

Clinical Trials on Not applicable, this is an observational study

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Austria

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe