The ESTxENDS Trial- Substudy on Effects of Using Electronic Nicotine Delivery Systems (ENDS) on Olfactory Function (ESTxENDS)

November 13, 2023 updated by: University of Bern

Substudy of Efficacy, Safety and Toxicology of Electronic Nicotine Delivery Systems as an Aid for Smoking Cessation (ESTxENDS Trial)- the Olfactory Function Substudy of ESTxENDS

--> This is a substudy of the main ESTxENDS trial (NCT03589989). Olfactory function outcomes should be considered secondary outcomes of the main smoking cessation outcome formulated in NCT03589989.

Up to one in five people have suffered loss or impairment of their sense of smell, limiting their available information about the environment, including possible hazards (e.g. gas or smoke). An impaired sense of smell is strongly associated with smoking, but its prevalence in smokers has yet to be established. Since only a few prospective cohort studies among smokers have compared change in olfactory function in smokers, it is not known how much or how fast smoking may impair olfactory function. Some studies describe improvement in olfactory function among quitters, supporting anecdotal evidence from ex-smokers who say they regained their sense of smell over time. As far as the investigators know, no randomized controlled trial has tested the effects of a smoking cessation intervention on olfactory function.

A reliable and validated olfactory function test is the Burghart Sniffin' Sticks 16-item Identification-test, which is quick and easy to administer. 16 familiar odours will be presented to the participants, each for 3-4 seconds. After each odour the participant is asked to select the correct answer from 4 possible answers.

With increasing popularity of e-cigarettes, their effect on the olfactory function also needs to be assessed. It is known, that e-cigarettes produce toxic compounds such as carbonyl and aldehydes, what could impair the sense of smell - especially if the liquid-level is too low or the temperature on the coil is too hot. This is the source of a phenomenon called "dry-hit", which is said to leave a burnt taste or smell to be recognized by users. However, it is unclear if e-cigarettes users with an olfactory dysfunction can adequately recognize a "dry-hit". Therefore, the goal is to investigate the effects of smoking cessation and use of ENDS on olfactory function and the recognition of a "dry-hit" from a test e-cigarette.

For the main ESTxENDS trial (NCT03589989), cigarette smokers motivated to quit smoking cigarettes will be included. Participants in the intervention group will receive an ENDS and nicotine-containing e-liquids, which they will be allowed to use ad libitum. Additionally, they will receive smoking cessation counseling. Participants in the control group will receive smoking cessation counseling only. All participants will be followed over a 24-month period. The primary objective is to assess changes in olfactory function from baseline to 6 months post target quit date (TQD) in cigarette smokers randomized to the intervention group compared to the control group.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

389

Phase

  • Not Applicable

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

  • Switzerland
      • Bern, Switzerland, 3010
        • University Clinic for General Internal Medicine, Bern University Hospital
      • Geneva, Switzerland, 1211
        • Département de médecine interne, Hôpitaux universitaires de Genève
      • Saint Gallen, Switzerland
        • Lungenzentrum, Klinik für Pneumologie und Schlafmedizin, Kantonsspital St. Gallen
      • Zürich, Switzerland
        • Epidemiology, Biostatistics and Prevention Institute (EBPI), University of Zurich
    • Vaud
      • Lausanne, Vaud, Switzerland, 1011
        • Unisanté, Centre universitaire de médecine générale et santé publique, Université de Lausanne

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

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Informed Consent as documented by signature
  • Persons aged 18 or older
  • Currently smoking 5 or more cigarettes a day for at least 12 months
  • Willing to try to quit smoking within the next 3 months,
  • Persons providing a valid phone number, a valid email address and/or a valid postal address.

Exclusion Criteria:

  • Known hypersensitivity or allergy to contents of the e-liquid
  • Participation in another study with investigational drug within the 30 days preceding the baseline visit and during the present study where interactions are to be expected
  • Women who are pregnant or breast feeding
  • Intention to become pregnant during the course of the scheduled study intervention, i.e. within the first 6-months of the study
  • Persons having used ENDS or tobacco heating systems regularly in the 3 months preceding the baseline visit
  • Persons having used nicotine replacement therapy (NRT) or other medications with demonstrated efficacy as an aid for smoking cessation such as varenicline or bupropion within the 3 months preceding the baseline visit
  • Persons who cannot attend the 6- month follow-up visit for any reason
  • Cannot understand instructions delivered in person or by phone, or otherwise unable to participate in study procedures

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

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Intervention group
Other: ENDS (vaporizer/e-cig) and smoking cessation counseling
Participants in the intervention group will receive an ENDS and nicotine-containing e-liquids, which they will be allowed to use ad libitum. Additionally, they will receive smoking cessation counseling. Participants will be allowed to additionally use nicotine replacement therapy. All participants will be followed over a 24-month period. Smoking cessation counseling will be provided in person at the first clinical visit and then over the phone at the target quit date one week later and again at week 2, 4 and 8 after the target quit date. After 6, 12 and 24 months, participants will be asked to come to a clinical visit.
Active Comparator: Control group
Other: Smoking cessation counseling
Participants in the control group will receive smoking cessation counseling only. Participants will be allowed to additionally use nicotine replacement therapy. All participants will be followed over a 24-month period. Smoking cessation counseling will be provided in person at the first clinical visit and then over the phone at the target quit date one week later and again at week 2, 4 and 8 after the target quit date. After 6, 12 and 24 months, participants will be asked to come to a clinical visit.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Assessment of olfactory function- Baseline
Time Frame: Baseline
Assessment of olfactory function with the Burghart Sniffin' Sticks 16-item Identification-test. The highest possible score is 16; the cut-off for hyposmia is 11 and cut-off for anosmia is 8.
Baseline
Assessment of olfactory function- follow-up
Time Frame: 6 months post quit date]
Assessment of olfactory function with the Burghart Sniffin' Sticks 16-item Identification-test. The highest possible score is 16; the cut-off for hyposmia is 11 and cut-off for anosmia is 8.
6 months post quit date]

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Assessment of change of olfactory function
Time Frame: change from baseline to 6 months post quit date
Assessment of change of olfactory function with the Burghart Sniffin' Sticks 16-item Identification-test. The highest possible score is 16; the cut-off for hyposmia is 11 and cut-off for anosmia is 8.
change from baseline to 6 months post quit date
Assessment of dry-hit recognition
Time Frame: 6 months post quit date

Assessment of dry-hit recognition. Participants will be given 2 ENDS to have them assess the probability of a dry-hit. The participants will be asked to rate the probability of a dry-hit in both ENDS as follows:

  1. Definitely (3 points)
  2. Probably (2 points)
  3. Probably not (1 points)
  4. Definitely not (0 points) 2 or 3 points will be interpreted as correctly identifying the ENDS generating a dry-hit.
6 months post quit date

Collaborators and Investigators

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

Sponsor

University of Bern

Collaborators

University of Zurich
Swiss National Science Foundation
University of Lausanne
University of Geneva, Switzerland
State Hospital, St. Gallen
Krebsforschung Schweiz, Bern, Switzerland
Federal Office of Public Health, Switzerland

Investigators

  • Study Director: Reto Auer, Prof.Dr.med, Berner Institut für Hausarztmedizin (BIHAM)

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

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)

September 7, 2020

Primary Completion (Actual)

August 31, 2023

Study Completion (Actual)

August 31, 2023

Study Registration Dates

First Submitted

October 24, 2020

First Submitted That Met QC Criteria

November 4, 2020

First Posted (Actual)

November 5, 2020

Study Record Updates

Last Update Posted (Actual)

November 15, 2023

Last Update Submitted That Met QC Criteria

November 13, 2023

Last Verified

November 1, 2023

More Information

Terms related to this study

Other Study ID Numbers

  • 2017-02332j

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.

Subscribe