Trial Outcomes & Findings for Financial Incentives for Homeless Smokers: A Community-based RCT (NCT NCT04445662)
NCT ID: NCT04445662
Last Updated: 2025-10-21
Results Overview
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.
Recruitment status
COMPLETED
Study phase
NA
Target enrollment
184 participants
Primary outcome timeframe
12 weeks
Results posted on
2025-10-21
Participant Flow
Recruitment took place between 2021-2024 at Boston Health Care for the Homeless Program (BHCHP), a federally funded Health Care for the Homeless (HCH) organization. Participants were recruited via in-person outreach at BHCHP clinic sites, telephone outreach to BHCHP patients with a past-year clinical encounter and electronic health record (EHR) documentation of current smoking, self-referrals in response to flyers or word of mouth, and referrals from BHCHP clinicians.
Enrolled participants provided written informed consent and completed a staff-administered baseline survey. To be assigned a study arm, enrolled participants were asked to attend a randomization appointment within 4 weeks of enrollment.
Participant milestones
| Measure |
Control (n=69)
* Varenicline
* Tobacco coaching
* Saliva cotinine monitoring with fixed payments ($10) regardless of results
Varenicline: - 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
Tobacco coaching: 5 one-on-one tobacco cessation coaching sessions over 12 weeks
|
Financial incentives (n=69)
* Varenicline
* Tobacco coaching
* Saliva cotinine monitoring with escalating payments ($25-70) for levels \<30 ng/ml
Financial incentives: Escalating financial rewards for saliva cotinine levels \<30 ng/mL, assessed 10 times over 12 weeks
Varenicline: - 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
Tobacco coaching: 5 one-on-one tobacco cessation coaching sessions over 12 weeks
|
|---|---|---|
|
On treatment (0-12 weeks)
STARTED
|
69
|
69
|
|
On treatment (0-12 weeks)
COMPLETED
|
65
|
64
|
|
On treatment (0-12 weeks)
NOT COMPLETED
|
4
|
5
|
|
Post-treatment (12-24 weeks)
STARTED
|
65
|
64
|
|
Post-treatment (12-24 weeks)
COMPLETED
|
64
|
64
|
|
Post-treatment (12-24 weeks)
NOT COMPLETED
|
1
|
0
|
Reasons for withdrawal
| Measure |
Control (n=69)
* Varenicline
* Tobacco coaching
* Saliva cotinine monitoring with fixed payments ($10) regardless of results
Varenicline: - 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
Tobacco coaching: 5 one-on-one tobacco cessation coaching sessions over 12 weeks
|
Financial incentives (n=69)
* Varenicline
* Tobacco coaching
* Saliva cotinine monitoring with escalating payments ($25-70) for levels \<30 ng/ml
Financial incentives: Escalating financial rewards for saliva cotinine levels \<30 ng/mL, assessed 10 times over 12 weeks
Varenicline: - 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
Tobacco coaching: 5 one-on-one tobacco cessation coaching sessions over 12 weeks
|
|---|---|---|
|
On treatment (0-12 weeks)
Deemed ineligible after randomization due to non-smoking status
|
1
|
0
|
|
On treatment (0-12 weeks)
Withdrawal by Subject
|
2
|
5
|
|
On treatment (0-12 weeks)
Withdrawn by PI due to behavioral concerns
|
1
|
0
|
|
Post-treatment (12-24 weeks)
Death
|
1
|
0
|
Baseline Characteristics
1 control arm participant did not answer enough questions to be categorized.
Baseline characteristics by cohort
| Measure |
Control (n=68)
n=68 Participants
* Varenicline
* Tobacco coaching
* Saliva cotinine monitoring with fixed payments ($10) regardless of results
Varenicline: - 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
Tobacco coaching: 5 one-on-one tobacco cessation coaching sessions over 12 weeks
|
Financial incentives (n=69)
n=69 Participants
* Varenicline
* Tobacco coaching
* Saliva cotinine monitoring with escalating payments ($25-70) for levels \<30 ng/ml
Financial incentives: Escalating financial rewards for saliva cotinine levels \<30 ng/mL, assessed 10 times over 12 weeks
Varenicline: - 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
Tobacco coaching: 5 one-on-one tobacco cessation coaching sessions over 12 weeks
|
Total
n=137 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Continuous
|
51.2 years
STANDARD_DEVIATION 10.3 • n=68 Participants
|
49.0 years
STANDARD_DEVIATION 10.1 • n=69 Participants
|
50.1 years
STANDARD_DEVIATION 10.2 • n=137 Participants
|
|
Sex/Gender, Customized
Gender · Male
|
44 Participants
n=68 Participants
|
56 Participants
n=69 Participants
|
100 Participants
n=137 Participants
|
|
Sex/Gender, Customized
Gender · Female
|
24 Participants
n=68 Participants
|
11 Participants
n=69 Participants
|
35 Participants
n=137 Participants
|
|
Sex/Gender, Customized
Gender · Other
|
0 Participants
n=68 Participants
|
2 Participants
n=69 Participants
|
2 Participants
n=137 Participants
|
|
Race/Ethnicity, Customized
Race/Ethnicity · Hispanic/Latine
|
6 Participants
n=68 Participants
|
17 Participants
n=69 Participants
|
23 Participants
n=137 Participants
|
|
Race/Ethnicity, Customized
Race/Ethnicity · Non-Hispanic Black
|
17 Participants
n=68 Participants
|
14 Participants
n=69 Participants
|
31 Participants
n=137 Participants
|
|
Race/Ethnicity, Customized
Race/Ethnicity · Non-Hispanic White
|
34 Participants
n=68 Participants
|
26 Participants
n=69 Participants
|
60 Participants
n=137 Participants
|
|
Race/Ethnicity, Customized
Race/Ethnicity · Non-Hispanic Other
|
11 Participants
n=68 Participants
|
10 Participants
n=69 Participants
|
21 Participants
n=137 Participants
|
|
Race/Ethnicity, Customized
Race/Ethnicity · Unknown
|
0 Participants
n=68 Participants
|
2 Participants
n=69 Participants
|
2 Participants
n=137 Participants
|
|
Homelessness status
Currently homeless
|
36 Participants
n=68 Participants
|
35 Participants
n=69 Participants
|
71 Participants
n=137 Participants
|
|
Homelessness status
Formerly homeless
|
32 Participants
n=68 Participants
|
34 Participants
n=69 Participants
|
66 Participants
n=137 Participants
|
|
Cigarettes per day
|
14.3 cigarettes
STANDARD_DEVIATION 6.8 • n=68 Participants
|
14.1 cigarettes
STANDARD_DEVIATION 7.3 • n=69 Participants
|
14.2 cigarettes
STANDARD_DEVIATION 7.0 • n=137 Participants
|
|
Alcohol use disorder
|
18 Participants
n=68 Participants
|
9 Participants
n=69 Participants
|
27 Participants
n=137 Participants
|
|
Drug use disorder
|
40 Participants
n=67 Participants • 1 control arm participant did not answer enough questions to be categorized.
|
39 Participants
n=69 Participants • 1 control arm participant did not answer enough questions to be categorized.
|
79 Participants
n=136 Participants • 1 control arm participant did not answer enough questions to be categorized.
|
|
Moderate/severe depression
|
25 Participants
n=68 Participants
|
27 Participants
n=69 Participants
|
52 Participants
n=137 Participants
|
|
Moderate/severe anxiety
|
28 Participants
n=68 Participants • 1 incentives arm participant did not answer enough questions to be categorized.
|
24 Participants
n=68 Participants • 1 incentives arm participant did not answer enough questions to be categorized.
|
52 Participants
n=136 Participants • 1 incentives arm participant did not answer enough questions to be categorized.
|
PRIMARY outcome
Timeframe: 12 weeksPoint-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.
Outcome measures
| Measure |
Control (n=68)
n=68 Participants
* Varenicline
* Tobacco coaching
* Saliva cotinine monitoring with fixed payments ($10) regardless of results
Varenicline: - 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
Tobacco coaching: 5 one-on-one tobacco cessation coaching sessions over 12 weeks
|
Financial incentives (n=69)
n=69 Participants
* Varenicline
* Tobacco coaching
* Saliva cotinine monitoring with escalating payments ($25-70) for levels \<30 ng/ml
Financial incentives: Escalating financial rewards for saliva cotinine levels \<30 ng/mL, assessed 10 times over 12 weeks
Varenicline: - 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
Tobacco coaching: 5 one-on-one tobacco cessation coaching sessions over 12 weeks
|
|---|---|---|
|
Cotinine-verified 7-day Smoking Abstinence at 12 Weeks
|
3 Participants
|
4 Participants
|
SECONDARY outcome
Timeframe: 24 weeksPoint-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.
Outcome measures
| Measure |
Control (n=68)
n=68 Participants
* Varenicline
* Tobacco coaching
* Saliva cotinine monitoring with fixed payments ($10) regardless of results
Varenicline: - 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
Tobacco coaching: 5 one-on-one tobacco cessation coaching sessions over 12 weeks
|
Financial incentives (n=69)
n=69 Participants
* Varenicline
* Tobacco coaching
* Saliva cotinine monitoring with escalating payments ($25-70) for levels \<30 ng/ml
Financial incentives: Escalating financial rewards for saliva cotinine levels \<30 ng/mL, assessed 10 times over 12 weeks
Varenicline: - 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
Tobacco coaching: 5 one-on-one tobacco cessation coaching sessions over 12 weeks
|
|---|---|---|
|
Cotinine-verified 7-day Smoking Abstinence at 24 Weeks
|
3 Participants
|
5 Participants
|
Adverse Events
Control (n=69)
Serious events: 3 serious events
Other events: 43 other events
Deaths: 1 deaths
Financial incentives (n=69)
Serious events: 2 serious events
Other events: 37 other events
Deaths: 0 deaths
Serious adverse events
| Measure |
Control (n=69)
n=69 participants at risk
* Varenicline
* Tobacco coaching
* Saliva cotinine monitoring with fixed payments ($10) regardless of results
Varenicline: - 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
Tobacco coaching: 5 one-on-one tobacco cessation coaching sessions over 12 weeks
|
Financial incentives (n=69)
n=69 participants at risk
* Varenicline
* Tobacco coaching
* Saliva cotinine monitoring with escalating payments ($25-70) for levels \<30 ng/ml
Financial incentives: Escalating financial rewards for saliva cotinine levels \<30 ng/mL, assessed 10 times over 12 weeks
Varenicline: - 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
Tobacco coaching: 5 one-on-one tobacco cessation coaching sessions over 12 weeks
|
|---|---|---|
|
Psychiatric disorders
Suicidality
|
2.9%
2/69 • Number of events 2 • From enrollment until end of study follow-up at 24 weeks.
Participant were asked whether they had experienced specific symptoms linked with varenicline use (e.g. abnormal dreams, headaches, nausea, vomiting, and suicidality) at each cotinine monitoring visit. Participants could also report adverse events at any other study visit or via phone call to study staff. For each AE reported, study staff assessed date of onset, level of severity, resolution status, expectedness, and relatedness to study protocol.
|
2.9%
2/69 • Number of events 2 • From enrollment until end of study follow-up at 24 weeks.
Participant were asked whether they had experienced specific symptoms linked with varenicline use (e.g. abnormal dreams, headaches, nausea, vomiting, and suicidality) at each cotinine monitoring visit. Participants could also report adverse events at any other study visit or via phone call to study staff. For each AE reported, study staff assessed date of onset, level of severity, resolution status, expectedness, and relatedness to study protocol.
|
|
General disorders
Collapsed
|
1.4%
1/69 • Number of events 1 • From enrollment until end of study follow-up at 24 weeks.
Participant were asked whether they had experienced specific symptoms linked with varenicline use (e.g. abnormal dreams, headaches, nausea, vomiting, and suicidality) at each cotinine monitoring visit. Participants could also report adverse events at any other study visit or via phone call to study staff. For each AE reported, study staff assessed date of onset, level of severity, resolution status, expectedness, and relatedness to study protocol.
|
0.00%
0/69 • From enrollment until end of study follow-up at 24 weeks.
Participant were asked whether they had experienced specific symptoms linked with varenicline use (e.g. abnormal dreams, headaches, nausea, vomiting, and suicidality) at each cotinine monitoring visit. Participants could also report adverse events at any other study visit or via phone call to study staff. For each AE reported, study staff assessed date of onset, level of severity, resolution status, expectedness, and relatedness to study protocol.
|
|
General disorders
Death
|
1.4%
1/69 • Number of events 1 • From enrollment until end of study follow-up at 24 weeks.
Participant were asked whether they had experienced specific symptoms linked with varenicline use (e.g. abnormal dreams, headaches, nausea, vomiting, and suicidality) at each cotinine monitoring visit. Participants could also report adverse events at any other study visit or via phone call to study staff. For each AE reported, study staff assessed date of onset, level of severity, resolution status, expectedness, and relatedness to study protocol.
|
0.00%
0/69 • From enrollment until end of study follow-up at 24 weeks.
Participant were asked whether they had experienced specific symptoms linked with varenicline use (e.g. abnormal dreams, headaches, nausea, vomiting, and suicidality) at each cotinine monitoring visit. Participants could also report adverse events at any other study visit or via phone call to study staff. For each AE reported, study staff assessed date of onset, level of severity, resolution status, expectedness, and relatedness to study protocol.
|
Other adverse events
| Measure |
Control (n=69)
n=69 participants at risk
* Varenicline
* Tobacco coaching
* Saliva cotinine monitoring with fixed payments ($10) regardless of results
Varenicline: - 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
Tobacco coaching: 5 one-on-one tobacco cessation coaching sessions over 12 weeks
|
Financial incentives (n=69)
n=69 participants at risk
* Varenicline
* Tobacco coaching
* Saliva cotinine monitoring with escalating payments ($25-70) for levels \<30 ng/ml
Financial incentives: Escalating financial rewards for saliva cotinine levels \<30 ng/mL, assessed 10 times over 12 weeks
Varenicline: - 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
Tobacco coaching: 5 one-on-one tobacco cessation coaching sessions over 12 weeks
|
|---|---|---|
|
General disorders
Headache
|
33.3%
23/69 • Number of events 30 • From enrollment until end of study follow-up at 24 weeks.
Participant were asked whether they had experienced specific symptoms linked with varenicline use (e.g. abnormal dreams, headaches, nausea, vomiting, and suicidality) at each cotinine monitoring visit. Participants could also report adverse events at any other study visit or via phone call to study staff. For each AE reported, study staff assessed date of onset, level of severity, resolution status, expectedness, and relatedness to study protocol.
|
26.1%
18/69 • Number of events 21 • From enrollment until end of study follow-up at 24 weeks.
Participant were asked whether they had experienced specific symptoms linked with varenicline use (e.g. abnormal dreams, headaches, nausea, vomiting, and suicidality) at each cotinine monitoring visit. Participants could also report adverse events at any other study visit or via phone call to study staff. For each AE reported, study staff assessed date of onset, level of severity, resolution status, expectedness, and relatedness to study protocol.
|
|
Psychiatric disorders
Abnormal Dreams
|
31.9%
22/69 • Number of events 24 • From enrollment until end of study follow-up at 24 weeks.
Participant were asked whether they had experienced specific symptoms linked with varenicline use (e.g. abnormal dreams, headaches, nausea, vomiting, and suicidality) at each cotinine monitoring visit. Participants could also report adverse events at any other study visit or via phone call to study staff. For each AE reported, study staff assessed date of onset, level of severity, resolution status, expectedness, and relatedness to study protocol.
|
34.8%
24/69 • Number of events 27 • From enrollment until end of study follow-up at 24 weeks.
Participant were asked whether they had experienced specific symptoms linked with varenicline use (e.g. abnormal dreams, headaches, nausea, vomiting, and suicidality) at each cotinine monitoring visit. Participants could also report adverse events at any other study visit or via phone call to study staff. For each AE reported, study staff assessed date of onset, level of severity, resolution status, expectedness, and relatedness to study protocol.
|
|
Gastrointestinal disorders
Nausea
|
31.9%
22/69 • Number of events 29 • From enrollment until end of study follow-up at 24 weeks.
Participant were asked whether they had experienced specific symptoms linked with varenicline use (e.g. abnormal dreams, headaches, nausea, vomiting, and suicidality) at each cotinine monitoring visit. Participants could also report adverse events at any other study visit or via phone call to study staff. For each AE reported, study staff assessed date of onset, level of severity, resolution status, expectedness, and relatedness to study protocol.
|
24.6%
17/69 • Number of events 24 • From enrollment until end of study follow-up at 24 weeks.
Participant were asked whether they had experienced specific symptoms linked with varenicline use (e.g. abnormal dreams, headaches, nausea, vomiting, and suicidality) at each cotinine monitoring visit. Participants could also report adverse events at any other study visit or via phone call to study staff. For each AE reported, study staff assessed date of onset, level of severity, resolution status, expectedness, and relatedness to study protocol.
|
|
General disorders
Insomnia
|
27.5%
19/69 • Number of events 20 • From enrollment until end of study follow-up at 24 weeks.
Participant were asked whether they had experienced specific symptoms linked with varenicline use (e.g. abnormal dreams, headaches, nausea, vomiting, and suicidality) at each cotinine monitoring visit. Participants could also report adverse events at any other study visit or via phone call to study staff. For each AE reported, study staff assessed date of onset, level of severity, resolution status, expectedness, and relatedness to study protocol.
|
14.5%
10/69 • Number of events 12 • From enrollment until end of study follow-up at 24 weeks.
Participant were asked whether they had experienced specific symptoms linked with varenicline use (e.g. abnormal dreams, headaches, nausea, vomiting, and suicidality) at each cotinine monitoring visit. Participants could also report adverse events at any other study visit or via phone call to study staff. For each AE reported, study staff assessed date of onset, level of severity, resolution status, expectedness, and relatedness to study protocol.
|
|
Psychiatric disorders
Aggressive/erratic behavior
|
11.6%
8/69 • Number of events 9 • From enrollment until end of study follow-up at 24 weeks.
Participant were asked whether they had experienced specific symptoms linked with varenicline use (e.g. abnormal dreams, headaches, nausea, vomiting, and suicidality) at each cotinine monitoring visit. Participants could also report adverse events at any other study visit or via phone call to study staff. For each AE reported, study staff assessed date of onset, level of severity, resolution status, expectedness, and relatedness to study protocol.
|
11.6%
8/69 • Number of events 8 • From enrollment until end of study follow-up at 24 weeks.
Participant were asked whether they had experienced specific symptoms linked with varenicline use (e.g. abnormal dreams, headaches, nausea, vomiting, and suicidality) at each cotinine monitoring visit. Participants could also report adverse events at any other study visit or via phone call to study staff. For each AE reported, study staff assessed date of onset, level of severity, resolution status, expectedness, and relatedness to study protocol.
|
|
Gastrointestinal disorders
Vomiting
|
11.6%
8/69 • Number of events 9 • From enrollment until end of study follow-up at 24 weeks.
Participant were asked whether they had experienced specific symptoms linked with varenicline use (e.g. abnormal dreams, headaches, nausea, vomiting, and suicidality) at each cotinine monitoring visit. Participants could also report adverse events at any other study visit or via phone call to study staff. For each AE reported, study staff assessed date of onset, level of severity, resolution status, expectedness, and relatedness to study protocol.
|
10.1%
7/69 • Number of events 9 • From enrollment until end of study follow-up at 24 weeks.
Participant were asked whether they had experienced specific symptoms linked with varenicline use (e.g. abnormal dreams, headaches, nausea, vomiting, and suicidality) at each cotinine monitoring visit. Participants could also report adverse events at any other study visit or via phone call to study staff. For each AE reported, study staff assessed date of onset, level of severity, resolution status, expectedness, and relatedness to study protocol.
|
|
Psychiatric disorders
Suicidality
|
5.8%
4/69 • Number of events 4 • From enrollment until end of study follow-up at 24 weeks.
Participant were asked whether they had experienced specific symptoms linked with varenicline use (e.g. abnormal dreams, headaches, nausea, vomiting, and suicidality) at each cotinine monitoring visit. Participants could also report adverse events at any other study visit or via phone call to study staff. For each AE reported, study staff assessed date of onset, level of severity, resolution status, expectedness, and relatedness to study protocol.
|
4.3%
3/69 • Number of events 3 • From enrollment until end of study follow-up at 24 weeks.
Participant were asked whether they had experienced specific symptoms linked with varenicline use (e.g. abnormal dreams, headaches, nausea, vomiting, and suicidality) at each cotinine monitoring visit. Participants could also report adverse events at any other study visit or via phone call to study staff. For each AE reported, study staff assessed date of onset, level of severity, resolution status, expectedness, and relatedness to study protocol.
|
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place