Smoking
Conditions
Brief summary
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.
Interventions
BEHAVIORALGroup commitment contract
1. 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. 2. 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. 3. 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.
BEHAVIORALSmoking 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.
Sponsors
National Institute on Aging (NIA)
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
Srinakharinwirot University
University of California, Berkeley
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
20 Years to No maximum
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Smoking Status at 6 Months | 6 months after enrollment | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Concordance of Smoking Status Between Partners at 6 Months | 6 months after enrollment | 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. |
| Smoking Status at 3 Months | 3 months after enrollment | 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. |
| Concordance of Smoking Status Between Partners at 3 Months | 3 months after enrollment | 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. |
| Smoking Status at 14 Months | 14 months after enrollment | 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. |
Countries
Thailand
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Group Commitment Contracts The intervention includes the following components:
1. 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.
2. 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.
3. 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.
4. 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. | 132 |
| 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.
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. | 69 |
| Total | 201 |
Baseline characteristics
| Characteristic | Group Commitment Contracts | Education and Counseling | Total |
|---|---|---|---|
| Age, Continuous | 51.05 years STANDARD_DEVIATION 13.82 | 51.07 years STANDARD_DEVIATION 14.04 | 51.06 years STANDARD_DEVIATION 13.86 |
| Education (years) 0-3 years | 62 Participants | 34 Participants | 96 Participants |
| Education (years) 4-6 years | 29 Participants | 22 Participants | 51 Participants |
| Education (years) 7 or more years | 40 Participants | 13 Participants | 53 Participants |
| Monthly household income | 4.011 USD, in 100s STANDARD_DEVIATION 5.805 | 3.513 USD, in 100s STANDARD_DEVIATION 2.809 | 3.838 USD, in 100s STANDARD_DEVIATION 4.971 |
| Race and Ethnicity Not Collected | — | — | 0 Participants |
| Region of Enrollment Thailand | 132 participants | 69 participants | 201 participants |
| Religion Buddhist | 91 Participants | 48 Participants | 139 Participants |
| Religion Muslim | 40 Participants | 21 Participants | 61 Participants |
| Sex: Female, Male Female | 16 Participants | 9 Participants | 25 Participants |
| Sex: Female, Male Male | 116 Participants | 60 Participants | 176 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 1 / 132 | 0 / 69 |
| other Total, other adverse events | 0 / 132 | 0 / 69 |
| serious Total, serious adverse events | 0 / 132 | 0 / 69 |
Outcome results
Primary
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.
Time frame: 6 months after enrollment
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Group Commitment Contracts | Smoking Status at 6 Months | 57 Participants |
| Education and Counseling | Smoking Status at 6 Months | 13 Participants |
Secondary
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.
Time frame: 3 months after enrollment
| Arm | Measure | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Group Commitment Contracts | Concordance of Smoking Status Between Partners at 3 Months | Both abstain | 35 Participants |
| Group Commitment Contracts | Concordance of Smoking Status Between Partners at 3 Months | Both smoke | 44 Participants |
| Group Commitment Contracts | Concordance of Smoking Status Between Partners at 3 Months | One abstains, one smokes | 49 Participants |
| Education and Counseling | Concordance of Smoking Status Between Partners at 3 Months | Both abstain | 0 Participants |
| Education and Counseling | Concordance of Smoking Status Between Partners at 3 Months | Both smoke | 40 Participants |
| Education and Counseling | Concordance of Smoking Status Between Partners at 3 Months | One abstains, one smokes | 15 Participants |
Secondary
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.
Time frame: 6 months after enrollment
Population: In the education and counseling group, this represents a partner who is randomly assigned to the person but whose identity is never revealed.
| Arm | Measure | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Group Commitment Contracts | Concordance of Smoking Status Between Partners at 6 Months | Both abstain | 31 Participants |
| Group Commitment Contracts | Concordance of Smoking Status Between Partners at 6 Months | Both smoke | 45 Participants |
| Group Commitment Contracts | Concordance of Smoking Status Between Partners at 6 Months | One abstains, one smokes | 51 Participants |
| Education and Counseling | Concordance of Smoking Status Between Partners at 6 Months | Both abstain | 2 Participants |
| Education and Counseling | Concordance of Smoking Status Between Partners at 6 Months | Both smoke | 36 Participants |
| Education and Counseling | Concordance of Smoking Status Between Partners at 6 Months | One abstains, one smokes | 17 Participants |
Secondary
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.
Time frame: 14 months after enrollment
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Group Commitment Contracts | Smoking Status at 14 Months | 53 Participants |
| Education and Counseling | Smoking Status at 14 Months | 17 Participants |
Secondary
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.
Time frame: 3 months after enrollment
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Group Commitment Contracts | Smoking Status at 3 Months | 60 Participants |
| Education and Counseling | Smoking Status at 3 Months | 10 Participants |