Clinical trial NCT04224727: The Impact of Group Commitment Contracts on Smoking Cessation and Weight Loss
Official title: The Impact of Group Commitment Contracts on Smoking Cessation and Weight Loss
Study type: INTERVENTIONAL
Overall status: SUSPENDED
Phase: NA
Conditions: Smoking Cessation
Weight Loss
Lead sponsor: National Bureau of Economic Research, Inc.
Sponsor class: OTHER
Collaborators: name: Northwestern University
First posted: 2020-01-13
Enrollment: 3600
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Respondents who meet the inclusion/exclusion criteria will be randomized into one of the following arms:

1. Control Arm (No Intervention)
2. Group Contract Arm
3. Individual Monetary Rewards Arm
4. Individual Commitment Contract Arm

To understand the effect that knowledge about the effectiveness of commitment contracts has on uptake, smoking quit rates, and weight loss, we will be cross-randomizing those assigned to Arms #2-4 into further subgroups:

Subgroup A. In the initial survey, participants will receive additional information treatments on the likelihood of success of the different incentives and contracts, with the goal of shifting "naives" to "sophisticates." In other words, we aim to provide information that will encourage present-biased or loss-averse individuals to participate in the programs that offer the greatest chance at success.

Subgroup B. Participants will not receive any information about commitment contracts.
Primary purpose: PREVENTION

Brief summary: We will conduct a randomized controlled trial to evaluate the effectiveness of group commitment contracts for smoking cessation and weight loss.

Detailed description: Initial screening will be conducted online via the Qualtrics survey platform. Respondents meeting the inclusion/exclusion criteria will immediately be randomized into one of the intervention arms described below, and then take a baseline survey. This baseline survey will also be conducted online via the Qualtrics survey platform. The initial screening, randomization, and baseline survey should take approximately 15 minutes total and can be completed anywhere the participant has an internet connection.

INTERVENTION: Respondents who meet the inclusion/exclusion criteria will be randomized into one of the following arms:

1. Control Arm (No Intervention)
2. Group Contract Arm
3. Individual Monetary Rewards Arm
4. Individual Commitment Contract Arm

Subjects in Arms #2-4 will be cross-randomized into two subgroups:

A. Additional information treatments on the likelihood of success of the different incentives and contracts, with the goal of shifting "naives" to "sophisticates."

B. No additional information treatments.

FOLLOW-UP SURVEY: After the participants finish their contract, they will be emailed a link to the follow-up survey that will be administered online via the Qualtrics survey platform. The survey should take approximately 5 minutes and can be completed anywhere the participant has an internet connection. Participants will be directly prompted to answer whether they have been able to quit smoking or lose their target weight in the past six months. If a participant self-reports a claim of smoking cessation or successful weight loss, they will be asked to furnish at-home verification of their claim.

IN-PERSON VERIFICATION: A randomly selected subset of successful participants will be asked for in-person verification of their claim with a urine test (smoking cessation) or in-person weigh-in (weight loss) at a Quest Diagnostics location of their choice.

Eligibility criteria: Inclusion Criteria:

* Aged 18 years or older
* Has smartphone with capability to reach internet daily and download app
* Able and willing to visit Quest location or take an at-home verification test
* Willing to furnish a payment method for commitment contract stakes

If completing a smoking cessation contract:

* Daily smoker

If completing a weight loss contract:

* Has access to a functioning scale
* Interest in losing weight at a pace of 2 lb or fewer per week, with a target BMI at or above 18.5

Exclusion Criteria:

* Pregnancy
* Any terminal illness

Primary outcomes:
measure: Smoking Cessation / Weight Loss
timeFrame: 6 months
Secondary outcomes:
Other outcomes:
measure: Smoking Cessation / Weight Loss by Sex/Gender, Race, and Ethnicity
timeFrame: 6 months
Locations:
city: Evanston
country: United States
facility: Northwestern University, Global Poverty Research Lab
state: Illinois
Study officials:
affiliation: Northwestern University
name: Dean Karlan, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Northwestern University
name: Anna Tuchman, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Dartmouth College
name: Jonathan Zinman, PhD
role: PRINCIPAL_INVESTIGATOR
References: