Financial Incentives for Homeless Smokers: A Community-based RCT

Study Overview
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Brief Summary
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This community-based randomized controlled trial will test the effect of contingent financial rewards on smoking abstinence among homeless-experienced adult cigarette smokers. Participants will be recruited from 3 Boston Health Care for the Homeless Program locations: a shelter clinic, a day center clinic, and a medical center clinic. All participants will be offered a varenicline prescription and tobacco coaching. Incentive arm participants will receive escalating financial rewards for saliva cotinine levels <30 ng/ml, assessed 10 times over 12 weeks. Embedded qualitative interviews will explore the mechanisms of on-treatment and post-treatment effects of financial incentives on smoking abstinence in the context of homelessness.

Detailed Description
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People experiencing homelessness have a 3.5-fold higher prevalence of cigarette smoking in comparison to non-homeless people, contributing to 2-fold higher rates of lung cancer and 3- to 5-fold higher rates of tobacco-attributable death. Homeless smokers want to quit, but studies have not yet uncovered the optimal approach to help them do so. In an 8-week pilot randomized controlled trial (RCT) at Boston Health Care for the Homeless Program (BHCHP), we found that financial incentives for smoking abstinence were associated with 7-fold higher odds of brief smoking abstinence in comparison to a non-incentivized control condition. These results suggest that financial incentives are a promising approach for reducing smoking in this vulnerable population, but further investigation in a larger sample is needed to improve the duration of on-treatment abstinence, assess post-treatment effects, and better understand mechanisms of action and contextual factors that may influence treatment response. To address the above gaps in evidence, we will conduct a community-based RCT of financial incentives for smoking abstinence among adult smokers at BHCHP. Recognized as a leader in homeless health care, BHCHP serves 12,000 currently and formerly homeless patients annually throughout greater Boston. We will randomize 180 participants recruited from 3 BHCHP sites: a shelter clinic, a day center clinic, and a medical center clinic. All participants will be offered 12 weeks of varenicline, 5 sessions of tobacco coaching, and 10 cotinine monitoring visits over a 12-week period. Participants randomized to the financial incentives arm (n=90) will receive escalating debit card payments (range $25-$70) at each monitoring visit for saliva cotinine levels <30 ng/ml. Control arm participants (n=90) will receive a fixed payment ($10) at each monitoring visit regardless of their saliva cotinine level. We will use an embedded-experiment mixed methods design, where qualitative ('qual') data collection is embedded within a larger quantitative ('QUAN') RCT with the following specific aims: Aim 1. (QUAN) To determine the effect of the financial incentives intervention on cotinine-verified 7-day smoking abstinence at A) the end of treatment (12 weeks) and B) 12 weeks after treatment (24 weeks). Hypotheses: Incentive arm participants will have significantly greater cotinine-verified 7-day smoking abstinence than control arm participants at A) 12 weeks and B) 24 weeks. Aim 2. (qual) To assess why, how, and under what circumstances homeless smokers A) achieve abstinence in response to financial incentives and B) maintain abstinence after incentives are stopped. Interviews with participants at A) 12 weeks (N=30) and B) 24 weeks (N=20) will examine cognitive ('why?'), procedural ('how?'), and contextual ('under what circumstances?') dimensions of their response to financial incentives to generate hypotheses about potential mechanisms for on-treatment and post-treatment effects and to inform modifications of the intervention for future use.

Official Title
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Financial Incentives for Homeless Smokers: A Community-based RCT

Conditions
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Tobacco Smoking

Intervention / Treatment
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* Behavioral: Financial incentives
* Drug: Varenicline
* Behavioral: Tobacco coaching


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age ≥18 years old Lifetime smoker of ≥100 cigarettes with current daily smoking of ≥5 cigarettes per day, verified by a saliva cotinine level of ≥30 ng/mL Ready to try quitting smoking within the next 3 months Proficient in English Currently or formerly homeless Have a primary care provider within BHCHP system Exclusion Criteria: Unable to provide informed consent History of allergic reaction to varenicline Currently pregnant, planning to become pregnant, or breastfeeding Past-month suicidal ideation with plan or intent, or past 12-month history of suicidal behaviors or attempts Psychiatric hospitalization in the past 3 months

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Control (n=90)<br>Varenicline Tobacco coaching Saliva cotinine monitoring with fixed payments ($10) regardless of results | Drug: Varenicline<br>* Day 1 - 3: 0.5 mg daily Day 4 - 7: 0.5 mg twice daily Day 8 - Week 12: 1 mg twice daily Dose/schedule may be adjusted based on medical history and clinician judgement<br>* Other names: Chantix;Behavioral: Tobacco coaching<br>* 5 one-on-one tobacco cessation coaching sessions over 12 weeks<br>* Other names: Smoking cessation counseling;|
| Experimental: Financial incentives (n=90)<br>Varenicline Tobacco coaching Saliva cotinine monitoring with escalating payments ($25-70) for levels <30 ng/ml | Behavioral: Financial incentives<br>* Escalating financial rewards for saliva cotinine levels <30 ng/mL, assessed 10 times over 12 weeks<br>* Other names: Contingency management;Drug: Varenicline<br>* Day 1 - 3: 0.5 mg daily Day 4 - 7: 0.5 mg twice daily Day 8 - Week 12: 1 mg twice daily Dose/schedule may be adjusted based on medical history and clinician judgement<br>* Other names: Chantix;Behavioral: Tobacco coaching<br>* 5 one-on-one tobacco cessation coaching sessions over 12 weeks<br>* Other names: Smoking cessation counseling;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cotinine-verified 7-day smoking abstinence at 12 weeks | Point-prevalent smoking abstinence, defined as self-report of not smoking in the past 7 days and verified by a salivary cotinine level <10 ng/ml. | 12 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cotinine-verified 7-day smoking abstinence at 24 weeks | Point-prevalent smoking abstinence, defined as self-report of not smoking in the past 7 days and verified by a salivary cotinine level <10 ng/ml. | 24 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Smoking Cessation, Homelessness, Financial Incentives