Using Group Commitment for Smoking Cessation

• ClinicalTrials.gov Identifier: NCT01311115
• Recruitment Status: Completed
• First Posted: March 9, 2011
• Results First Posted: September 15, 2022
• Last Update Posted: September 15, 2022
• Sponsor: University of California, Berkeley
• Collaborators: National Institute on Aging (NIA); Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD); Srinakharinwirot University
• Information provided by (Responsible Party): William Dow, University of California, Berkeley

• Study Type: Interventional
• Study Design: Allocation: Randomized; Intervention Model: Parallel Assignment; Masking: Single (Outcomes Assessor); Primary Purpose: Treatment
• Condition: Smoking
• Interventions: Behavioral: Group commitment contract; Behavioral: Smoking cessation education and counseling
• Enrollment: 201

Participant Flow

Recruitment Details
Pre-assignment Details

Arm/Group Title	Group Commitment Contracts	Education and Counseling
Arm/Group Description	The intervention includes the following components: Education and counseling (same as control group): Participants receive educational pamphlets on reasons to quit smoking and strategies for quitting smoking. They also receive one-time, group counseling on quitting smoking from a nurse trained in smoking cessation counseling.; Each participant is required to deposit at least 50 baht at enrollment. A deposit collector visits each participant on a weekly basis and collects additional deposits on a voluntary basis. All deposits are returned only if the smoker quits successfully within three months.; The project gives a matching contribution of 150 baht for the initial deposit of at least 50 baht. All participants in the treatment group are further randomized to a one-month group and a three-month group. The one-month group receives an additional 150 baht of project funds if they deposit 100 baht of their money within one month of enrollment. The three-month group receives 150 baht for depositing 100 baht within three months of enrollment.; Each participant is paired with another study participant at enrollment. If both quit, each receives a cash bonus of 1,200 baht. At enrollment, pairs receive brief counseling on ways to support each other during the quit attempt.	Participants in this group receive educational pamphlets about quitting smoking and one-time, group counseling from a nurse trained in smoking cessation counseling. Smoking cessation education and counseling: Participants receive educational pamphlets on reasons to quit smoking and strategies for quitting smoking. They also receive one-time, group counseling on quitting smoking from a nurse trained in smoking cessation counseling.
Period Title: Overall Study
Started	132	69
Completed	132	69
Not Completed	0	0

Baseline Characteristics

Arm/Group Title		Group Commitment Contracts	Education and Counseling	Total
Arm/Group Description		The intervention includes the following components: Education and counseling (same as control group): Participants receive educational pamphlets on reasons to quit smoking and strategies for quitting smoking. They also receive one-time, group counseling on quitting smoking from a nurse trained in smoking cessation counseling.; Each participant is required to deposit at least 50 baht at enrollment. A deposit collector visits each participant on a weekly basis and collects additional deposits on a voluntary basis. All deposits are returned only if the smoker quits successfully within three months.; The project gives a matching contribution of 150 baht for the initial deposit of at least 50 baht. All participants in the treatment group are further randomized to a one-month group and a three-month group. The one-month group receives an additional 150 baht of project funds if they deposit 100 baht of their money within one month of enrollment. The three-month group receives 150 baht for depositing 100 baht within three months of enrollment.; Each participant is paired with another study participant at enrollment. If both quit, each receives a cash bonus of 1,200 baht. At enrollment, pairs receive brief counseling on ways to support each other during the quit attempt.	Participants in this group receive educational pamphlets about quitting smoking and one-time, group counseling from a nurse trained in smoking cessation counseling. Smoking cessation education and counseling: Participants receive educational pamphlets on reasons to quit smoking and strategies for quitting smoking. They also receive one-time, group counseling on quitting smoking from a nurse trained in smoking cessation counseling.	Total of all reporting groups
Overall Number of Baseline Participants		132	69	201
Baseline Analysis Population Description		[Not Specified]
Age, Continuous; Mean (Standard Deviation); Unit of measure: Years
	Number Analyzed	132 participants	69 participants	201 participants
		51.05 (13.82)	51.07 (14.04)	51.06 (13.86)
Sex: Female, Male; Measure Type: Count of Participants; Unit of measure: Participants
	Number Analyzed	132 participants	69 participants	201 participants
	Female	16 12.1%	9 13.0%	25 12.4%
	Male	116 87.9%	60 87.0%	176 87.6%
Race and Ethnicity Not Collected [1]; Measure Type: Count of Participants; Unit of measure: Participants
	Number Analyzed	0 participants	0 participants	0 participants
				0
		[1] Measure Analysis Population Description: Race and Ethnicity were not collected from any participant.
Region of Enrollment; Measure Type: Number; Unit of measure: Participants
Thailand	Number Analyzed	132 participants	69 participants	201 participants
		132	69	201
Religion [1]; Measure Type: Count of Participants; Unit of measure: Participants
	Number Analyzed	131 participants	69 participants	200 participants
	Buddhist	91 69.5%	48 69.6%	139 69.5%
	Muslim	40 30.5%	21 30.4%	61 30.5%
		[1] Measure Analysis Population Description: Missing baseline data
Education (years) [1]; Measure Type: Count of Participants; Unit of measure: Participants
	Number Analyzed	131 participants	69 participants	200 participants
	0-3 years	62 47.3%	34 49.3%	96 48.0%
	4-6 years	29 22.1%	22 31.9%	51 25.5%
	7 or more years	40 30.5%	13 18.8%	53 26.5%
		[1] Measure Analysis Population Description: Missing baseline data
Monthly household income [1]; Mean (Standard Deviation); Unit of measure: USD, in 100s
	Number Analyzed	131 participants	69 participants	200 participants
		4.011 (5.805)	3.513 (2.809)	3.838 (4.971)
		[1] Measure Analysis Population Description: Missing baseline data

Outcome Measures

1. Primary Outcome

Title	Smoking Status at 6 Months
Description	7-day point prevalence of smoking abstinence measured 6 months after enrollment, using a NicCheck urine cotinine test. Participants who self-report having smoked in the last 7 days, as part of the follow-up survey, are considered to be continuing smokers.
Time Frame	6 months after enrollment

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Group Commitment Contracts	Education and Counseling
Arm/Group Description:	The intervention includes the following components: Education and counseling (same as control group): Participants receive educational pamphlets on reasons to quit smoking and strategies for quitting smoking. They also receive one-time, group counseling on quitting smoking from a nurse trained in smoking cessation counseling.; Each participant is required to deposit at least 50 baht at enrollment. A deposit collector visits each participant on a weekly basis and collects additional deposits on a voluntary basis. All deposits are returned only if the smoker quits successfully within three months.; The project gives a matching contribution of 150 baht for the initial deposit of at least 50 baht. All participants in the treatment group are further randomized to a one-month group and a three-month group. The one-month group receives an additional 150 baht of project funds if they deposit 100 baht of their money within one month of enrollment. The three-month group receives 150 baht for depositing 100 baht within three months of enrollment.; Each participant is paired with another study participant at enrollment. If both quit, each receives a cash bonus of 1,200 baht. At enrollment, pairs receive brief counseling on ways to support each other during the quit attempt.	Participants in this group receive educational pamphlets about quitting smoking and one-time, group counseling from a nurse trained in smoking cessation counseling. Smoking cessation education and counseling: Participants receive educational pamphlets on reasons to quit smoking and strategies for quitting smoking. They also receive one-time, group counseling on quitting smoking from a nurse trained in smoking cessation counseling.
Overall Number of Participants Analyzed	128	68
Measure Type: Count of Participants; Unit of Measure: Participants
	57 44.5%	13 19.1%

2. Secondary Outcome

Title	Concordance of Smoking Status Between Partners at 6 Months
Description	The concordance of smoking status among randomly assigned pairs: both abstain, both smoke, or one abstains and one smokes, measured using 7-day point-prevalence abstinence at 6 months after enrollment, measured using self-reported abstinence and urine cotinine testing. Participants in the control condition are assigned to a pair, but their partner's identity is never revealed during the study.
Time Frame	6 months after enrollment

Outcome Measure Data

Analysis Population Description

In the education and counseling group, this represents a partner who is randomly assigned to the person but whose identity is never revealed.

Arm/Group Title	Group Commitment Contracts	Education and Counseling
Arm/Group Description:	The intervention includes the following components: Education and counseling (same as control group): Participants receive educational pamphlets on reasons to quit smoking and strategies for quitting smoking. They also receive one-time, group counseling on quitting smoking from a nurse trained in smoking cessation counseling.; Each participant is required to deposit at least 50 baht at enrollment. A deposit collector visits each participant on a weekly basis and collects additional deposits on a voluntary basis. All deposits are returned only if the smoker quits successfully within three months.; The project gives a matching contribution of 150 baht for the initial deposit of at least 50 baht. All participants in the treatment group are further randomized to a one-month group and a three-month group. The one-month group receives an additional 150 baht of project funds if they deposit 100 baht of their money within one month of enrollment. The three-month group receives 150 baht for depositing 100 baht within three months of enrollment.; Each participant is paired with another study participant at enrollment. If both quit, each receives a cash bonus of 1,200 baht. At enrollment, pairs receive brief counseling on ways to support each other during the quit attempt.	Participants in this group receive educational pamphlets about quitting smoking and one-time, group counseling from a nurse trained in smoking cessation counseling. Smoking cessation education and counseling: Participants receive educational pamphlets on reasons to quit smoking and strategies for quitting smoking. They also receive one-time, group counseling on quitting smoking from a nurse trained in smoking cessation counseling.
Overall Number of Participants Analyzed	127	55
Measure Type: Count of Participants; Unit of Measure: Participants
Both abstain	31 24.4%	2 3.6%
Both smoke	45 35.4%	36 65.5%
One abstains, one smokes	51 40.2%	17 30.9%

3. Secondary Outcome

Title	Smoking Status at 3 Months
Description	7-day point prevalence of smoking abstinence measured 3 months after enrollment, using a NicCheck urine cotinine test. Participants who self-report having smoked in the last 7 days, as part of the follow-up survey, are considered to be continuing smokers.
Time Frame	3 months after enrollment

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Group Commitment Contracts	Education and Counseling
Arm/Group Description:	The intervention includes the following components: Education and counseling (same as control group): Participants receive educational pamphlets on reasons to quit smoking and strategies for quitting smoking. They also receive one-time, group counseling on quitting smoking from a nurse trained in smoking cessation counseling.; Each participant is required to deposit at least 50 baht at enrollment. A deposit collector visits each participant on a weekly basis and collects additional deposits on a voluntary basis. All deposits are returned only if the smoker quits successfully within three months.; The project gives a matching contribution of 150 baht for the initial deposit of at least 50 baht. All participants in the treatment group are further randomized to a one-month group and a three-month group. The one-month group receives an additional 150 baht of project funds if they deposit 100 baht of their money within one month of enrollment. The three-month group receives 150 baht for depositing 100 baht within three months of enrollment.; Each participant is paired with another study participant at enrollment. If both quit, each receives a cash bonus of 1,200 baht. At enrollment, pairs receive brief counseling on ways to support each other during the quit attempt.	Participants in this group receive educational pamphlets about quitting smoking and one-time, group counseling from a nurse trained in smoking cessation counseling. Smoking cessation education and counseling: Participants receive educational pamphlets on reasons to quit smoking and strategies for quitting smoking. They also receive one-time, group counseling on quitting smoking from a nurse trained in smoking cessation counseling.
Overall Number of Participants Analyzed	128	68
Measure Type: Count of Participants; Unit of Measure: Participants
	60 46.9%	10 14.7%

4. Secondary Outcome

Title	Concordance of Smoking Status Between Partners at 3 Months
Description	The concordance of smoking status among randomly assigned pairs: both abstain, both smoke, or one abstains and one smokes, measured using 7-day point-prevalence abstinence at 3 months after enrollment, measured using self-reported abstinence and urine cotinine testing. Participants in the control condition are assigned to a pair, but their partner's identity is never revealed during the study.
Time Frame	3 months after enrollment

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Group Commitment Contracts	Education and Counseling
Arm/Group Description:	The intervention includes the following components: Education and counseling (same as control group): Participants receive educational pamphlets on reasons to quit smoking and strategies for quitting smoking. They also receive one-time, group counseling on quitting smoking from a nurse trained in smoking cessation counseling.; Each participant is required to deposit at least 50 baht at enrollment. A deposit collector visits each participant on a weekly basis and collects additional deposits on a voluntary basis. All deposits are returned only if the smoker quits successfully within three months.; The project gives a matching contribution of 150 baht for the initial deposit of at least 50 baht. All participants in the treatment group are further randomized to a one-month group and a three-month group. The one-month group receives an additional 150 baht of project funds if they deposit 100 baht of their money within one month of enrollment. The three-month group receives 150 baht for depositing 100 baht within three months of enrollment.; Each participant is paired with another study participant at enrollment. If both quit, each receives a cash bonus of 1,200 baht. At enrollment, pairs receive brief counseling on ways to support each other during the quit attempt.	Participants in this group receive educational pamphlets about quitting smoking and one-time, group counseling from a nurse trained in smoking cessation counseling. Smoking cessation education and counseling: Participants receive educational pamphlets on reasons to quit smoking and strategies for quitting smoking. They also receive one-time, group counseling on quitting smoking from a nurse trained in smoking cessation counseling.
Overall Number of Participants Analyzed	128	55
Measure Type: Count of Participants; Unit of Measure: Participants
Both abstain	35 27.3%	0 0.0%
Both smoke	44 34.4%	40 72.7%
One abstains, one smokes	49 38.3%	15 27.3%

5. Secondary Outcome

Title	Smoking Status at 14 Months
Description	7-day point prevalence of smoking abstinence measured 6 months after enrollment, using a NicCheck urine cotinine test. Participants who self-report having smoked in the last 7 days, as part of the follow-up survey, are considered to be continuing smokers.
Time Frame	14 months after enrollment

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Group Commitment Contracts	Education and Counseling
Arm/Group Description:	The intervention includes the following components: Education and counseling (same as control group): Participants receive educational pamphlets on reasons to quit smoking and strategies for quitting smoking. They also receive one-time, group counseling on quitting smoking from a nurse trained in smoking cessation counseling.; Each participant is required to deposit at least 50 baht at enrollment. A deposit collector visits each participant on a weekly basis and collects additional deposits on a voluntary basis. All deposits are returned only if the smoker quits successfully within three months.; The project gives a matching contribution of 150 baht for the initial deposit of at least 50 baht. All participants in the treatment group are further randomized to a one-month group and a three-month group. The one-month group receives an additional 150 baht of project funds if they deposit 100 baht of their money within one month of enrollment. The three-month group receives 150 baht for depositing 100 baht within three months of enrollment.; Each participant is paired with another study participant at enrollment. If both quit, each receives a cash bonus of 1,200 baht. At enrollment, pairs receive brief counseling on ways to support each other during the quit attempt.	Participants in this group receive educational pamphlets about quitting smoking and one-time, group counseling from a nurse trained in smoking cessation counseling. Smoking cessation education and counseling: Participants receive educational pamphlets on reasons to quit smoking and strategies for quitting smoking. They also receive one-time, group counseling on quitting smoking from a nurse trained in smoking cessation counseling.
Overall Number of Participants Analyzed	128	68
Measure Type: Count of Participants; Unit of Measure: Participants
	53 41.4%	17 25.0%

Adverse Events

Time Frame	[Not Specified]
Adverse Event Reporting Description	[Not Specified]
Arm/Group Title	Group Commitment Contracts	Education and Counseling
Arm/Group Description	The intervention includes the following components: Education and counseling (same as control group): Participants receive educational pamphlets on reasons to quit smoking and strategies for quitting smoking. They also receive one-time, group counseling on quitting smoking from a nurse trained in smoking cessation counseling.; Each participant is required to deposit at least 50 baht at enrollment. A deposit collector visits each participant on a weekly basis and collects additional deposits on a voluntary basis. All deposits are returned only if the smoker quits successfully within three months.; The project gives a matching contribution of 150 baht for the initial deposit of at least 50 baht. All participants in the treatment group are further randomized to a one-month group and a three-month group. The one-month group receives an additional 150 baht of project funds if they deposit 100 baht of their money within one month of enrollment. The three-month group receives 150 baht for depositing 100 baht within three months of enrollment.; Each participant is paired with another study participant at enrollment. If both quit, each receives a cash bonus of 1,200 baht. At enrollment, pairs receive brief counseling on ways to support each other during the quit attempt.	Participants in this group receive educational pamphlets about quitting smoking and one-time, group counseling from a nurse trained in smoking cessation counseling. Smoking cessation education and counseling: Participants receive educational pamphlets on reasons to quit smoking and strategies for quitting smoking. They also receive one-time, group counseling on quitting smoking from a nurse trained in smoking cessation counseling.
All-Cause Mortality
	Group Commitment Contracts	Education and Counseling
	Affected / at Risk (%)	Affected / at Risk (%)
Total	1/132 (0.76%)	0/69 (0.00%)
Serious Adverse Events
	Group Commitment Contracts	Education and Counseling
	Affected / at Risk (%)	Affected / at Risk (%)
Total	0/132 (0.00%)	0/69 (0.00%)
Other (Not Including Serious) Adverse Events
Frequency Threshold for Reporting Other Adverse Events	0%
	Group Commitment Contracts	Education and Counseling
	Affected / at Risk (%)	Affected / at Risk (%)
Total	0/132 (0.00%)	0/69 (0.00%)

Limitations and Caveats

[Not Specified]

More Information

Certain Agreements

Principal Investigators are NOT employed by the organization sponsoring the study.

There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.

Results Point of Contact

• Name/Title: Justin White
• Organization: University of California, San Francisco
• Phone: 415-476-8045
• EMail: Justin.White@ucsf.edu

Publications of Results:

White JS, Dow WH, Rungruanghiranya S. Commitment contracts and team incentives: a randomized controlled trial for smoking cessation in Thailand. Am J Prev Med. 2013 Nov;45(5):533-42. doi: 10.1016/j.amepre.2013.06.020.

• Responsible Party: William Dow, University of California, Berkeley
• ClinicalTrials.gov Identifier: NCT01311115
• Other Study ID Numbers: 2010-04-1269; 2P30AG012839-16 ( U.S. NIH Grant/Contract ); R21HD056581 ( U.S. NIH Grant/Contract )
• First Submitted: March 8, 2011
• First Posted: March 9, 2011
• Results First Submitted: August 23, 2022
• Results First Posted: September 15, 2022
• Last Update Posted: September 15, 2022