Tobacco Use and Uptake of COVID-19 Vaccinations

May 3, 2023 updated by: Finnish Institute for Health and Welfare

Tobacco Use and Uptake of COVID-19 Vaccinations in Finland: a General Population Study

This is an observational study of participants in two general population health surveys (FinSote 2018 and 2020) who are followed up for their COVID-19 vaccinations or end of follow-up. The primary objective is to examine the association between tobacco use and COVID-19 vaccine uptake and between-dose spacing.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Detailed Description

Most high income countries have rolled out COVID-19 vaccinations, with the promise of reducing incident COVID-19 infections and preventing hospitalizations and deaths. A high vaccination coverage is crucial for several reasons: (i) to reduce the number of new COVID-19 cases, (ii) to diminish selective pressures leading to the emergence of new variants of concern, (iii) to prevent severe COVID-19 outcomes, such as hospitalizations and deaths, and (iv) to potentially reduce the risk of post-acute COVID-19 symptoms.

Smokers are at higher risk of COVID-19 hospitalizations and deaths and might thus benefit greatly from high vaccination coverage. However, evidence suggests that they may be less likely to be vaccinated, as smokers are less likely to adhere to preventive measures in general and have lower adherence to other vaccines. Reports of a protective role of smoking on the risk of COVID-19 infection might have also reduced the perceived risks from being infected.

Evidence regarding tobacco use and COVID-19 vaccine hesitancy is mixed. Some studies have shown greater mistrust in COVID-19 vaccine benefits and greater vaccine hesitancy and lower vaccine acceptance compared to non-smokers, while other studies have reported no differences by smoking status or lower levels of vaccine hesitancy in smokers compared to non-smokers. Few studies have examined the relationship between tobacco use and vaccine uptake, showing that smokers had higher odds of being vaccinated. These studies, however, are not representative of the general population and relied on self-reported vaccination status, resulting in higher risk of selection and information bias.

The investigators will expand current knowledge by examining two forms of tobacco use in Finland -smoking and smokeless tobacco use (snus)- and by analysing the spacing between vaccine doses. The study will use data from nationally representative surveys in Finland linked to vaccination registries, which reduces the risk of selection and information bias.

Study Type

Observational

Enrollment (Actual)

42935

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
    • Uusimaa
      • Helsinki, Uusimaa, Finland, 00271
        • Finnish Institute for Health and Welfare

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

Sampling Method

Probability Sample

Study Population

Permanent residents in Finland aged 20 and over who participated in the FinSote surveys in 2018 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 or 2020
  • Provided consent for register linkage

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
  • Did not provide consent for register linkage

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

  • Observational Models: Cohort
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Tobacco users

Tobacco users

Never smokers (reference group) will be compared with former smokers, occasional smokers and daily smokers.

Never snus users (reference group) will also compare with never users, former users and current 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
Vaccination uptake of at least two doses of a COVID-19 vaccine
Time Frame: Baseline until date of vaccination or May 31, 2022
Proportion of participants with at least two doses of a COVID-19 vaccine
Baseline until date of vaccination or May 31, 2022

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Vaccination uptake of at least one dose of a COVID-19 vaccine
Time Frame: Baseline until date of vaccination or May 31, 2022
Proportion of participants with at least one dose of a COVID-19 vaccine
Baseline until date of vaccination or May 31, 2022
Vaccination uptake of complete COVID-19 vaccination scheme (two doses and a booster dose)
Time Frame: Baseline until date of vaccination or May 31, 2022
Proportion of participants with two doses and a booster dose of a COVID-19 vaccine
Baseline until date of vaccination or May 31, 2022
Spacing of first and second COVID-19 dose
Time Frame: Baseline until date of vaccination or May 31, 2022
Proportion of participants with more than 7 months between the first and second COVID-19 dose
Baseline until date of vaccination or May 31, 2022
Spacing of second dose and booster dose of the COVID-19 vaccine
Time Frame: Baseline until date of vaccination or May 31, 2022
Proportion of participants with more than 7 months between the second dose and booster dose of the COVID-19 vaccine
Baseline until date of vaccination or May 31, 2022

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 (Anticipated)

June 1, 2023

Study Completion (Anticipated)

June 1, 2023

Study Registration Dates

First Submitted

July 28, 2022

First Submitted That Met QC Criteria

July 28, 2022

First Posted (Actual)

July 29, 2022

Study Record Updates

Last Update Posted (Estimate)

May 5, 2023

Last Update Submitted That Met QC Criteria

May 3, 2023

Last Verified

May 1, 2023

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • THL/713/6.00.00/2021.2

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.

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