Using Group Commitment for Smoking Cessation

This study proposes a novel behavioral intervention to help smokers in Thailand to achieve their goals of quitting. Smoking treatment programs are rare throughout most of Asia and unlikely to meet the impending demand for quitting that tobacco control regulations is stimulating. New approaches are needed.

The present study is a randomized controlled trial to test the effectiveness of a novel, scalable approach to smoking cessation that is targeted toward rural Southeast Asian communities. Thailand is used as a test case to explore if pairs of smokers quit successfully after making financially-backed commitments and receiving cash incentives to quit. The control group receives education and counseling about quitting. In addition to education and counseling about quitting, the intervention includes two key components:

1. Each participant is encouraged to deposit his "cigarette money" on a weekly basis, to be returned only if the smoker quits successfully within three months. Such commitment contracts, based on theory from behavioral economics, are designed to help a person to maintain self-control and motivation in the face of temptation.
2. Each participant is paired with another study participant. If both quit, each receives a cash bonus. The joint incentives are designed to lead partners to support each other throughout the quit attempt.

Thus, group commitment contracts marshal a robust blend of elements: financial commitment, social support, peer pressure, and monetary rewards. A larger, follow-up evaluation will clarify the relative importance of each of these elements.

Study Overview

• Status: Completed
• Conditions: Smoking
• Intervention / Treatment: Behavioral: Group commitment contract; Behavioral: Smoking cessation education and counseling

• Study Type: Interventional
• Enrollment (Actual): 201
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Thailand
  • Nakhon Nayok
    • Ongkharak, Nakhon Nayok, Thailand, 26120
      • Srinakharinwirot University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Current smoker of at least 10 cigarettes per week and at least 100 cigarettes over the course of a lifetime
• Residents of the study area in Nakhon Nayok province, which includes the six subdistricts of Klong Yai, Chumpon, Bueng San, Pak Phli, Khao Phoem, or Ongkharak

Exclusion Criteria:

• Pregnant
• Plans to leave the study area within the next 12 months

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: SINGLE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: Group commitment contracts; In addition to education and counseling, the intervention includes the following components: Each participant is encouraged to deposit his "cigarette money" on a weekly basis, to be returned only if the smoker quits successfully within three months.; The project gives a series of two matching contributions of 150 baht each to participants who meet certain deposit requirements.; Each participant is paired with another study participant. 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.	Behavioral: Group commitment contract; 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. 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.; Other Names: Commitment contract; Deposit contract; Contingency contract; Buddy intervention; Partner intervention; Behavioral: 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.; Other Names: Smoking cessation counseling
ACTIVE_COMPARATOR: Education and counseling; Participants in this group receive educational pamphlets about quitting smoking and one-time, group counseling from a nurse trained in smoking cessation counseling.	Behavioral: 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.; Other Names: Smoking cessation counseling

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Smoking Status at 6 Months	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.	6 months after enrollment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Concordance of Smoking Status Between Partners at 6 Months	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.	6 months after enrollment
Smoking Status at 3 Months	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.	3 months after enrollment
Concordance of Smoking Status Between Partners at 3 Months	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.	3 months after enrollment
Smoking Status at 14 Months	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.	14 months after enrollment

Collaborators and Investigators

• Sponsor: University of California, Berkeley
• Collaborators: Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD); National Institute on Aging (NIA); Srinakharinwirot University
• Investigators: Study Director: Justin S White, MA, MSPH, University of California at Berkeley; Principal Investigator: William H Dow, PhD, University of California at Berkeley; Study Director: Suthat Rungruanghiranya, MD, Srinakharinwirot University

Publications and helpful links

General Publications

• 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.

Study record dates

Study Major Dates

• Study Start: November 1, 2010
• Primary Completion (ACTUAL): August 1, 2011
• Study Completion (ACTUAL): March 1, 2012

Study Registration Dates

• First Submitted: March 8, 2011
• First Submitted That Met QC Criteria: March 8, 2011
• First Posted (ESTIMATE): March 9, 2011

Study Record Updates

• Last Update Posted (ACTUAL): September 15, 2022
• Last Update Submitted That Met QC Criteria: August 23, 2022
• Last Verified: August 1, 2022

More Information

Terms related to this study

• Other Study ID Numbers: 2010-04-1269; 2P30AG012839-16 (NIH); R21HD056581 (NIH)