Trial Outcomes & Findings for Human Perception of Odors and Odor Blockers (NCT NCT06191419)
NCT ID: NCT06191419
Last Updated: 2026-07-23
Results Overview
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.
COMPLETED
NA
27 participants
3 hours (total for all outcome measures)
2026-07-23
Participant Flow
All participants assessed for eligibility were enrolled and started the study procedures.
Participant milestones
| Measure |
Participants That Smoke
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.
Odorants: 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.
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|---|---|
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Overall Study
STARTED
|
27
|
|
Overall Study
Assessed for Eligibility
|
27
|
|
Overall Study
Cigarette Smoke Alone
|
27
|
|
Overall Study
Cigarette Smoke and Citronella Methyl 2 Methylbutyrate
|
27
|
|
Overall Study
Cigarette Smoke and Lemon Oil
|
27
|
|
Overall Study
Cigarette Smoke and Pentanethiol
|
27
|
|
Overall Study
Cigarette Smoke and Mineral Oil
|
27
|
|
Overall Study
COMPLETED
|
22
|
|
Overall Study
NOT COMPLETED
|
5
|
Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Human Perception of Odors and Odor Blockers
Baseline characteristics by cohort
| Measure |
Participants That Smoke
n=27 Participants
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.
Odorants: 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.
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|---|---|
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Age, Categorical
<=18 years
|
0 Participants
n=9 Participants
|
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Age, Categorical
Between 18 and 65 years
|
27 Participants
n=9 Participants
|
|
Age, Categorical
>=65 years
|
0 Participants
n=9 Participants
|
|
Sex: Female, Male
Female
|
18 Participants
n=9 Participants
|
|
Sex: Female, Male
Male
|
9 Participants
n=9 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
4 Participants
n=9 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
23 Participants
n=9 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=9 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=9 Participants
|
|
Race (NIH/OMB)
Asian
|
0 Participants
n=9 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=9 Participants
|
|
Race (NIH/OMB)
Black or African American
|
3 Participants
n=9 Participants
|
|
Race (NIH/OMB)
White
|
24 Participants
n=9 Participants
|
|
Race (NIH/OMB)
More than one race
|
0 Participants
n=9 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=9 Participants
|
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Region of Enrollment
United States
|
27 participants
n=9 Participants
|
PRIMARY outcome
Timeframe: 3 hours (total for all outcome measures)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.
Outcome measures
| Measure |
Participants That Smoke
n=22 Participants
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.
Odorants: 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.
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|---|---|
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Cigarette Purchase Task
Cigarette Smoke and Pentanethiol
|
-0.622 Log (US Dollars)
Standard Deviation 1.343
|
|
Cigarette Purchase Task
Cigarette Smoke Alone
|
-0.176 Log (US Dollars)
Standard Deviation 1.205
|
|
Cigarette Purchase Task
Cigarette Smoke and Citronella Methyl 2 Methylbutyrate
|
-0.128 Log (US Dollars)
Standard Deviation 1.188
|
|
Cigarette Purchase Task
Cigarette Smoke and Lemon Oil
|
1.28 Log (US Dollars)
Standard Deviation 1.026
|
|
Cigarette Purchase Task
Cigarette Smoke and Mineral Oil
|
-0.267 Log (US Dollars)
Standard Deviation 1.207
|
PRIMARY outcome
Timeframe: 3 hours (total for all outcome measures)A rating of participant's desire to smoke on a scale of 0 - 100, where a higher score indicates increased desire.
Outcome measures
| Measure |
Participants That Smoke
n=22 Participants
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.
Odorants: 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.
|
|---|---|
|
Desire to Smoke
Cigarette Smoke Alone
|
36.8 score on a scale
Standard Deviation 31.4
|
|
Desire to Smoke
Cigarette Smoke and Citronella Methyl 2 Methylbutyrate
|
32.3 score on a scale
Standard Deviation 29.1
|
|
Desire to Smoke
Cigarette Smoke and Lemon Oil
|
34.0 score on a scale
Standard Deviation 30.7
|
|
Desire to Smoke
Cigarette Smoke and Pentanethiol
|
23.9 score on a scale
Standard Deviation 29.1
|
|
Desire to Smoke
Cigarette Smoke and Mineral Oil
|
32.0 score on a scale
Standard Deviation 33.8
|
SECONDARY outcome
Timeframe: 3 hours (total for all outcome measures)Participants complete a forced-choice test by rating whether the odor is pleasant or unpleasant. Responses were recorded as a binary measure where 0=unpleasant and 1=pleasant. Scores range from 0 to 1, with higher score indicate greater odor pleasantness.
Outcome measures
| Measure |
Participants That Smoke
n=22 Participants
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.
Odorants: 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.
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|---|---|
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Odor Pleasantness Score
Cigarette Smoke and Mineral Oil
|
0.48 score on a scale
Standard Deviation 0.51
|
|
Odor Pleasantness Score
Cigarette Smoke Alone
|
0.43 score on a scale
Standard Deviation 0.50
|
|
Odor Pleasantness Score
Cigarette Smoke and Citronella Methyl 2 Methylbutyrate
|
0.55 score on a scale
Standard Deviation 0.50
|
|
Odor Pleasantness Score
Cigarette Smoke and Lemon Oil
|
0.82 score on a scale
Standard Deviation 0.39
|
|
Odor Pleasantness Score
Cigarette Smoke and Pentanethiol
|
0.16 score on a scale
Standard Deviation 0.37
|
Adverse Events
Participants That Smoke
Serious adverse events
Adverse event data not reported
Other adverse events
Adverse event data not reported
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place