Human Perception of Odors and Odor Blockers

NCT06191419 | Completed Results

• 2 other identifiers: 431231K18DC020155
• Study Type: interventional
• Target: 27
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to determine whether blockers of perception of key odorants in cigarette smoke have any utility in smoking cessation. The main question it aims to answer is: • Can odor blockers be used to suppress perception of the intensity of cigarette smoke in ways that reduce the ability of the odor of cigarette smoke to increase the urge to smoke. Participants will be asked to smell up to 20 odor samples per session and report on odor pleasantness and desire to smoke.

Conditions

Tobacco Smoking; Smoking Behaviors

Keywords

Odors; Sensory perception; Nicotine addiction; Motivation

Outcome Measures

Primary Outcomes (2)

• Cigarette Purchase Task

  The Cigarette Purchase Task (Strickland et al., 2016) requires selecting how much the smoker is willing to spend for a single cigarette (their preferred brand) from a list of 19 amounts ranging from $0.00 (free) to $1,120. The measure from the selections is the breakpoint where the participants are no longer willing to purchase. These data are skewed and are log transformed (after adding 0.01) for statistical analysis.

  3 hours (total for all outcome measures)

• Desire to Smoke

  A rating of participant's desire to smoke on a scale of 0 - 100, where a higher score indicates increased desire.

  3 hours (total for all outcome measures)

Secondary Outcomes (1)

• Odor Pleasantness Score

  3 hours (total for all outcome measures)

Study Arms (1)

Participants that Smoke

EXPERIMENTAL

Each smoker is asked to smell up to 20 samples per session. Samples include controls (clean air, irrelevant odor), blocking odors, cigarette smoke, and cigarette smoke mixed with blocking odors or irrelevant odors.

Other: Odorants

Interventions

Odorants OTHER

Each smoker is assigned a CPAP nose mask. Odor sample bags are attached to the mask. Smokers open the valve, inhale once through the nose, close the valve, remove the bag from the mask and report on the odor.

Participants that Smoke

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Smoker

You may not qualify if:

• Non Smoker
• Self reported inability to smell or taste

Sponsors & Collaborators

• National Institute on Deafness and Other Communication Disorders (NIDCD): collaborator
• Tim McClintock: lead

Study Sites (1)

University of Kentucky

Lexington, Kentucky, 40536, United States

Location

MeSH Terms

Conditions

Tobacco Smoking; Smoking; Tobacco Use Disorder

Interventions

Odorants

Condition Hierarchy (Ancestors)

Behavior; Tobacco Use; Substance-Related Disorders; Chemically-Induced Disorders; Mental Disorders

Intervention Hierarchy (Ancestors)

Environment; Ecological and Environmental Phenomena; Biological Phenomena; Environment and Public Health

Results Point of Contact

• Title: Timothy McClintock
• Organization: University of Kentucky

mcclint@uky.edu

8593231083

Study Officials

• Timothy McClintock, PhD

  University of Kentucky

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: Yes

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Masking Details: Odor bags are prepared by one staff member and labeled with a code so that other investigators administering tests cannot identify which treatment is being given and inadvertently influence outcomes. The code is not visible to participants. This prevents participants from anticipating the effect of the treatment.
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Professor

Model Details: Each subject experiences and reports on all of the odor blocker and control treatments.

Study Record Dates

• First Submitted: December 20, 2023
• First Posted: January 5, 2024
• Study Start: April 5, 2024
• Primary Completion: May 15, 2025
• Study Completion: May 15, 2025
• Last Updated: July 23, 2026
• Results First Posted: July 8, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)