Skip to main content
NCBI home page
NIHPA Author Manuscripts logoLink to NIHPA Author Manuscripts
. Author manuscript; available in PMC: 2018 Oct 1.
Published in final edited form as: Exp Clin Psychopharmacol. 2017 Oct;25(5):333–337. doi: 10.1037/pha0000151

An Open-Label Pilot Study of an Intervention Using Mobile Phones to Deliver Contingency Management of Tobacco Abstinence to High School Students

Grace Kong 1, Alissa Goldberg 1, Jesse Dallery 2, Suchitra Krishnan-Sarin 1
PMCID: PMC5687821  NIHMSID: NIHMS910334  PMID: 29048181

Abstract

This pilot study assessed the feasibility, acceptability, and preliminary efficacy of a smoking cessation intervention that used mobile phones to remotely deliver reinforcements contingent on tobacco abstinence (contingency management [CM]), and weekly in-person cognitive behavioral therapy, to adolescent smokers. Daily adolescent smokers (N = 15; 12 completed study procedures, 3 dropped out) were recruited to participate in a four-week study. During the first two weeks, daily text messages sent at random times prompted participants to transmit a video of themselves providing a carbon monoxide (CO) sample. During the last two weeks, text messages sent on three randomly chosen days each week prompted participants to transmit a video of themselves providing a saliva sample. Negative samples (CO ≤ 8 ppm; cotinine ≤ 100 ng/ml) were reinforced with monetary incentives. Feasibility was assessed using the number of on-time, valid videos, and acceptability was determined using participant perceptions of the intervention. Seven-day point-prevalence (PP) abstinence (self-reported abstinence, cotinine <100 ng/ml) was assessed at end-of-treatment (EOT) and at a one-month follow-up. The study findings indicate that remote delivery of CM using mobile phones was feasible (85.8% of the CO videos and 67% of the saliva cotinine videos were on-time) and acceptable (positive perceptions of the CM procedures). Seven-day PP was 60% at EOT and 46.7% at the follow-up. Although larger randomized controlled trials are needed to evaluate efficacy, this pilot study suggests that the use of mobile phones to deliver CM for smoking cessation among adolescent smokers was acceptable and feasible.

Keywords: adolescents, smoking cessation, contingency management, intervention, mobile phone, text messaging, mobile health

Despite the decline in youth smoking in the recent decades; 9.3% of high school students still report smoking cigarettes (Singh, Arrazola, & Corey, 2016). More effective tobacco cessation programs are needed as current strategies are not especially effective for adolescent smokers (Backinger & Leischow, 2001; Grimshaw, Stanton, & Lancaster, 2006; Sussman, 2002; Sussman & Sun, 2009; Sussman, Sun, & Dent, 2006; Wiehe, Garrison, Christakis, Ebel, & Rivara, 2005).

Contingency management (CM) interventions that provide reinforcers based on biochemically confirmed abstinence have been effective in reducing tobacco use (Cavallo et al., 2007; Dallery et al., 2013; Krishnan-Sarin et al., 2013; Krishnan-Sarin et al., 2006). Despite the efficacy of CM, its dissemination is hindered by the high response effort to obtain frequent, sustained biochemical measures of smoking status (Dallery & Raiff, 2011). Most CM procedures provide reinforcement after confirming that breath carbon monoxide (CO) is below a cut point (typically 4–8 ppm) at least twice per day (e.g., Krishnan-Sarin et al., 2006; Tevyaw et al., 2009). These intensive CM procedures are more difficult to conduct with adolescents whose smoking behaviors are constrained due to being in school (Mermelstein et al., 2002). For instance, if an adolescent had last smoked in the morning before school, the CO breath test administered after school may not detect CO because of its short half-life (4–6 hours); therefore, compromising the validity of the intervention.

Some of these concerns can be addressed by delivering CM using the Internet (Dallery & Glenn, 2005; Dallery, Glenn, & Raiff, 2007). This method requires the participants to upload a video of themselves providing CO samples using a web camera to the study website. A randomized control trial (RCT) of this intervention with adult smokers showed that the Internet-based CM group (N = 39) achieved higher abstinence rates (CO ≤ 4 ppm) than the non-contingent group (N = 38; 66.7% vs. 25%) (Dallery, Raiff, & Grabinski, 2013). The feasibility of this treatment was also assessed among rural adults (Stoops et al., 2009) and adolescents (Reynolds, Dallery, Shroff, Patak, & Leraas, 2008). A single-case study with four adolescent smokers found that adolescents provided 97.2% of the CO samples and achieved prolonged abstinence (Reynolds et al., 2008). This collective evidence indicates that CO can be obtained and used to verify smoking abstinence remotely using the Internet with adolescents.

The delivery of CM for smoking cessation can be further improved by using mobile phone technology. Mobile phones are widely accessible, cost-effective, and used by individuals of all socioeconomic backgrounds and ages (Smith, 2011). In 2015, 75% of adolescents reported accessing the Internet using their mobile phones (Lenhart, 2015).

Mobile phones have been used to deliver CM interventions for smoking cessation in adults. Specifically, Hertzberg and colleagues (2013) delivered CM for smoking cessation using mobile phones with 22 adult smokers with posttraumatic stress disorder (PTSD). Compliance was 92%, and abstinence determined by a CO of ≤ 8 in the mobile phone CM group was 85%, relative to 45% in the control group. However, whether mobile phones can be used to deliver CM for smoking cessation among adolescents has not yet been examined.

We conducted an open-label pilot study to examine the feasibility, acceptability, and the initial efficacy of CM of tobacco abstinence delivered via mobile phones for four weeks to adolescent smokers. We used video recording and text messaging features on mobile phones to verify abstinence remotely. Participants also received weekly in-person cognitive behavioral therapy (CBT). During the first two weeks of the intervention, we verified abstinence remotely via daily CO levels, and then in the last two weeks, we verified abstinence remotely via saliva cotinine thrice per week. We used saliva cotinine during the last two weeks because of evidence suggesting that it could be used to reinforce smoking cessation (e.g., Gayman, Anderson, & Pietras, 2017), and that CO measurements are more sensitive to detecting abstinence during the initial quit days and cotinine levels are appropriate once abstinence is achieved (Schepis et al., 2008).

Methods

Participants

Adolescent daily smokers in New Haven County, Connecticut (N = 15; 60% girls, 60% White, 20% Hispanic, 13.3% Black, 6.7% mixed race, 16.47 years old [SD = 1.19]) participated in the study between February 2015 and July 2016. Recruitment occurred at high schools and interested participants were provided with brochures containing treatment information for their parents. Prior to starting treatment, parental permission and assent from adolescents <18 years old and consent from adolescents 18 years old were obtained.

See Figure 1 for reasons for exclusion and the flow of participants from initial contact to one-month follow up appointment. Eligibility criteria were: 1) ages 13–18, 2) daily smokers willing to participate in a four-week long smoking cessation program, 3) not meeting the DSM-IV criteria for substance dependence and any other major psychological disorders, and 4) ownership of a mobile phone with video recording capability and a data and a text messaging plan. All study procedures were approved by the Yale School of Medicine Human Investigation Committee and the participating schools.

Figure 1. Reasons for exclusion and flow of participants from initial contact to follow up.

Figure 1

Open in a new tab

*One participant who dropped out during treatment completed the follow up assessment.

Procedure

The CBT procedure

Participants received manualized weekly, in-person CBT for smoking cessation (See Cavallo et al., 2007; Krishnan-Sarin et al., 2006, 2013 for detailed information on the CBT). In brief, participants received a “Preparation to Quit” session five days prior to the quit day. This session was used to provide support for quitting and set up a quit plan. A “Pre-quit” session conducted one day prior to the quit day reviewed the quit plan. This was followed by four weekly CBT sessions that taught various smoking cessation skills (e.g., relapse prevention, coping with cravings, tobacco refusal skills).

The CM procedure

Contingent monetary reinforcement for abstinence was provided remotely via mobile phones based on CO levels (≤ 8 ppm on the Micro Direct Smoke Check CO Monitor, Med-Electronics, Beltsville, MD) daily during the first two weeks. Semi-quantitative saliva cotinine levels ≤ 2 (≤ 100 ng/ml; NicAlert saliva screen, ACCUTEST® Jant Pharmacal Corporation, Enrico, CA) determined abstinence remotely thrice per week in the last two weeks. These CO and cotinine values were used to determine smoking abstinence among adolescents previously (e.g., Krishnan-Sarin et al., 2006).

At the “Pre-quit” CBT session, participants were provided with a CO monitor and instructions on providing a CO sample. All CO monitors had Bluetooth trackers to locate the them if they were misplaced.

A valid CO video had to show 1) the CO monitor being reset, 2) the participant exhaling into the CO monitor, and 3) the final reading of the CO level on the monitor. Daily prompts started four days prior to the quit day to ensure that participants understood the CM procedures; during this period, participants were reinforced for providing on-time, valid recordings, but the payments were not contingent on abstinence. Reinforcement was contingent on abstinence starting from the quit day.

For the final two weeks, text prompts were sent thrice per week at random days/times to provide the saliva cotinine samples remotely. Participants were provided with instructions on providing the saliva sample. A valid saliva video had to show the participant 1) opening the saliva strip, 2) writing the date on the back of the strip, 3) providing saliva in the saliva funnel, and 4) squeezing drops of saliva onto the strip. The participants also had to transmit a picture of the saliva strip showing the results to the study phone before the end of the day. There were no time restrictions on the submission of the saliva cotinine video because of its long half-life. Adolescents had to submit the used saliva screens at their weekly in-person CBT appointments.

All text message prompts to provide a biochemical sample were sent at random times within a pre-set time period during the school days (3PM–8PM) and weekends/holidays (10AM–8PM). Adolescents were not prompted while they were at school or at work. To ensure that participants were providing real-time videos when prompted, daily code words that they had to say at the beginning of the video recording were sent in their text message prompts. If the video was not received within a specified time, a reminder text message with encouragement and possible compensations for the video submission was sent. See Supplemental Material for the preset list of text message prompts and responses. Participants redeemed earned monetary amount for cash at the weekly CBT appointments.

A progressively increasing schedule of reinforcement with a reset contingency was used (i.e., $2 for the first negative test day followed by a $0.50 increment for each consecutive negative test, with a reset to $1 for a positive test). Participants could also earn $1 for each on-time, valid breath CO and $3 for each on-time, valid saliva cotinine, regardless of their CO/saliva level (The payments for saliva videos were greater than CO videos so that the total weekly payments for video submission were comparable.), and a $10 bonus each week if all submitted videos for that week were on-time and valid. Participants were allowed two late/missed biochemical samples without the negative consequences (Reynolds et al., 2008). Additionally, participants received $10 for the intake and $10 for the one-month follow up. The maximum amount that could be earned was $256. Participants earned an average of $130.07 (SD = $54.56).

Measures

Baseline measures

We assessed age, sex, race/ethnicity, the number of cigarettes smoked per day, and cigarette dependence, measured with the modified Fagerström (Prokhorov, 1996) at the intake appointment.

Feasibility

Feasibility was determined using the number of on-time, valid CO and saliva videos submitted during the four-week intervention.

Acceptability

Perceptions of various components of the treatment were assessed at the EOT, as described below. Also see Table 1 for questions and response options.

Table 1.

Acceptability assessments of the mobile phone CM intervention (N = 12).

Constructs Questions Response options
Very easy/Somewhat easy Neither difficult nor easy Very difficult/Somewhat difficult
Providing CO/saliva samples using the mobile phone How easy or difficult was it to provide the CO video? 83.4% 16.7% 0%
How easy or difficult was it to provide the saliva video? 50% 8.3% 41.6%
Strongly/somewhat agree neutral Strongly disagree/somewhat disagree
Text message content, tone, and frequency The message tone was positive and made me feel supported. 100% 0% 0%
The message tone was annoying. 0% 16.7% 83.3%
The message was too long. 0% 16.7% 83.3%
The number of messages that I received each day was just right. 91.7% 8.3% 0%
Perceptions of the program I would recommend this program to my friend. 91.7% 8.3% 0%
I enjoyed participating in this program 83.4% 8.3% 8.3%
Open in a new tab

Participants rated how easy or difficult it was to provide the CO and the saliva samples remotely. They also answered open-ended questions on the CO and saliva video submission process, “What would make the [CO video/saliva video] recording process easier?”

Participants rated the content, tone (e.g., “annoying,” “positive,” “supportive”), and frequency (e.g., “too long,” “too many”) of the text messages. They also answered open-ended questions assessing components of the program that they liked and disliked.

Abstinence

Seven-day point-prevalence (PP) abstinence, defined as a self-report of abstinence seven days prior to EOT and at one-month follow up (using timeline follow back; (Lewis-Esquerre et al., 2005; Sobell & Sobell, 1992), verified by semi-quantitative saliva cotinine levels ≤ 100 ng/ml (Krishnan-Sarin 2006; 2013). Participants who dropped out of treatment (N = 3) were considered non-abstinent at the EOT. However, we obtained seven-day PP at the follow-up appointment for one of these three participants, but the remaining two participants were considered non-abstinent at the follow-up.

Results

At baseline, participants smoked 6.40 cigarettes per day (SD = 4.24), had baseline saliva cotinine of 2.60 (SD = .91), and had average modified Fagerström scores of 1.83 (SD = 1.08).

Feasibility

Average on-time, valid CO videos were 76.7% during the four practice days, 87.8% during the first week, 83.7% during the second week, and saliva videos were 64.3% during the third week and 69.7% during the fourth week.

Acceptability

The majority reported that providing CO samples using mobile phones was easy but the responses about providing the saliva samples were mixed (Table 1). Open-ended responses confirmed that CO procedures were easy (e.g., “I feel that they are simple and straight forward.” “It was overall pretty easy.”), but some reported difficulties with the saliva cotinine procedures (e.g., “The saliva video recording was overall pretty difficult – having to split on camera and record yourself putting spit on the strip.” “If the part we spit in came out much easier when we squeezed in on the strip.”). The text message tone and frequency/duration of the messages were perceived positively (Table 1).

In general, the program was also rated very positively (e.g., enjoyed being in the program and wanting to recommend the program to a friend; Table 1). The open-ended responses revealed appealing aspects: 1) support received (e.g., “Encourages me every day not to smoke,” “It helped me stay positive and find ways to fight the urge to smoke.”), 2) being on a quit schedule and setting goals (e.g., “Helped me quit on an organized schedule,” “It helped me to set goals for myself and reaching those goals was very inspiring,”), and 3) the monetary reinforcement (e.g., “I got paid”). Some suggested areas for improvement included more inperson support (e.g., It’s not that I didn’t like anything, just wish there were more counseling time.”), more payment (e.g., I didn’t like that I didn’t make as much money as planned,” “nothing, but getting paid less”), and sending videos on time (e.g., “sending the video on time was getting frustrating but it wasn’t a huge issue,” “The 30 minutes video due time.”), and providing saliva samples remotely.

Abstinence

The seven-day EOT PP abstinence was 60% and seven-day follow-up PP was 46.7%. The negative CO samples were submitted 57.2% during the four practice days and 86% during the first two weeks, and the negative saliva samples were submitted 67% during the last two weeks. The number of cigarettes smoked at baseline was not associated with abstinence at EOT (rpb (15) = −.45, p = .091) or at the one-month follow up (rpb (15) = −.35, p = .198).

Discussion

This pilot study examined the use of mobile phones to deliver contingency management (CM) to reinforce tobacco abstinence among adolescent smokers. The results of this study indicate that the use of text messaging and video recording features on mobile phones to deliver CM was acceptable and feasible to adolescent smokers. The quit rate (seven-day end-of-treatment [EOT] point prevalence [PP]) of 60% observed using mobile phone CM was comparable to those observed using in-person CM procedures in our earlier CM trials with adolescent smokers (38–57%; Cavallo et al., 2007; Krishnan-Sarin et al., 2013; Krishnan-Sarin et al., 2006).

The acceptability ratings, which assessed the frequency and the tone of the text messages, the procedures for providing CO/saliva samples via mobile phones, and the overall perceptions about the program, were positive. However, some participants found the procedures for providing saliva samples difficult, as reflected by the lower compliance rates observed with provision of saliva versus CO samples. The decrease in compliance with the saliva submission may be also related to the fact that unlike the immediate reinforcement provided for negative breath CO levels, participants did not receive immediate reinforcement for negative saliva cotinine levels. Immediacy of reinforcement is an important factor in incentive-based interventions (Stitzer & Petry, 2006). Although future studies are needed to improve the use of mobile phones to obtain saliva samples, this pilot study demonstrated the acceptability of the use of mobile phones to deliver CM for smoking cessation to adolescents.

Mobile phones can expand the reach of effective smoking cessation interventions to vulnerable populations, such as youth (Kong, Ells, Camenga, & Krishnan-Sarin, 2014) and could provide a cost-effective method for reinforcing behaviors among adolescents because of the elimination of face-to-face meetings. Mobile phones could also be used to target collection of biochemical samples at times when youth are at risk for smoking, while avoiding interference with school and work.

Despite the strengths of this study, there are also several limitations that need to be considered. While we did not encounter problems with access to cellular service, it is possible that certain disadvantaged communities, especially those in remote locations, could have poor cellular services or not have access to mobile phones. Additionally, while participants in this study were daily smokers, they had low nicotine dependence scores. Future studies should also examine the feasibility of this intervention in heavier smokers. However, since adolescent smoking is the lowest it has been in recent years (Singh et al., 2016), future work should also consider non-daily cigarette smokers. Another limitation is the small sample size of this pilot study. Adequately powered randomized controlled trials (RCTs) are needed to assess the potential use of mobile phones to deliver CM for smoking abstinence to youth.

In conclusion, this open-label pilot study suggests that the use of mobile phones to deliver reinforcement for abstaining from cigarette smoking is a promising way to engage adolescents and promote tobacco abstinence.

Supplementary Material

1

Public Health Statement.

This pilot study suggests that delivering reinforcements contingent on tobacco abstinence remotely using mobile phones to promote smoking cessation among adolescent smokers is feasible and acceptable.

References

  1. Backinger CL, Leischow SJ. Advancing the science of adolescent tobacco use cessation. American Journal of Health Behavior. 2001;25(3):183–190. doi: 10.5993/ajhb.25.3.4. [DOI] [PubMed] [Google Scholar]
  2. Cavallo DA, Cooney JL, Duhig AM, Smith AE, Liss TB, McFetridge AK, Krishnan-Sarin S. Combining cognitive behavioral therapy with contingency management for smoking cessation in adolescent smokers: a preliminary comparison of two different CBT formats. American Journal on Addictions. 2007;16(6):468–474. doi: 10.1080/10550490701641173. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Dallery J, Glenn IM. Effects of an Internet-based voucher reinforcement program for smoking abstinence: A feasibility study. Journal of Applied Behavior Analysis. 2005;38:349–357. doi: 10.1901/jaba.2005.150-04. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Dallery J, Glenn IM, Raiff BR. An Internet-based abstinence reinforcement treatment for cigarette smoking. Drug and Alcohol Dependence. 2007;86:230–238. doi: 10.1016/j.drugalcdep.2006.06.013. http://dx.doi.org/10.1016/j.drugalcdep.2006.06.013. [DOI] [PubMed] [Google Scholar]
  5. Dallery J, Raiff BR. Contingency management in the 21st century: Technological innovations to promote smoking cessatoin. Substance Use & Misuse. 2011;46:10–22. doi: 10.3109/10826084.2011.521067. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Dallery J, Raiff BR, Grabinski MJ. Internet-based contingency management to promote smoking cessation: A randomized controlled study. Journal of Applied Behavior Analysis. 2013;46(4):750–764. doi: 10.1002/jaba.89. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Gayman C, Anderson K, Pietras C. Saliva cotinine as a measure of smoking abstinence in contingency management – A feasibility study. The Psychological Record. 2017;67:261–272. doi: 10.1007/s40732-017-0240-5. [DOI] [Google Scholar]
  8. Grimshaw GM, Stanton A, Lancaster T. Tobacco cessation interventions for young people. Cochrane Database of Systematic Reviews. 2006;4 doi: 10.1002/14651858.CD003289.pub4. [DOI] [PubMed] [Google Scholar]
  9. Hertzberg JS, Carpenter VL, Kirby AC, Calhoun PS, Moore SD, Dennis MF, Beckham JC. Mobile contingency management as an adjunctive smoking cessation treatment for smokers with posttraumatic stress disorder. Nicotine & Research Tobacco. 2013;15:1934–1938. doi: 10.1093/ntr/ntt060. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Kong G, Ells D, Camenga D, Krishnan-Sarin S. Text message interventions for smoking cessation. A narrative review. Addictive Behaviors. 2014;39:907–917. doi: 10.1016/j.addbeh.2013.11.024. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Krishnan-Sarin S, Cavallo DA, Cooney JL, Schepis TS, Kong G, Liss TB, Carroll KM. An exploratory randomized controlled trial of a novel high-school-based smoking cessation intervention for adolescent smokers using abstinence-contingent incentives and cognitive behavioral therapy. Drug and Alcohol Dependence. 2013;132:346–351. doi: 10.1016/j.drugalcdep.2013.03.002. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Krishnan-Sarin S, Duhig AM, McKee SA, McMahon TJ, Liss T, McFetridge A, Cavallo DA. Contingency management for smoking cessation in adolescent smokers. Experimental and Clinical Psychopharmacology. 2006;14(3):306–310. doi: 10.1037/1064-1297.14.3.306. [DOI] [PubMed] [Google Scholar]
  13. Lenhart A. Teens, social media & technology overview 2015. 2015 Retrieved from. [Google Scholar]
  14. Lewis-Esquerre JM, Colby SM, Tevyaw TOL, Eaton CA, Kahler CW, Monti PM. Validation of the timeline follow-back in the assessment of adolescent smoking. Drug and Alcohol Dependence. 2005;79(1):33–43. doi: 10.1016/j.drugalcdep.2004.12.007. https://doi.Org/10.1016/j.drugalcdep.2004.12.007. [DOI] [PubMed] [Google Scholar]
  15. Mermelstein R, Colby SM, Patten C, Prokhorov A, Brown R, Myers M, McDonald P. Methodological issues in measuring treatment outcome in adolescent smoking cessation studies. Nicotine & Tobacco Research. 2002;312:996–1469. doi: 10.1080/1462220021000018470. [DOI] [PubMed] [Google Scholar]
  16. Reynolds B, Dallery J, Shroff P, Patak M, Leraas K. A web-based contingency management program with adolescent smokers. Journal of Applied Behavior Analysis. 2008;41:597–601. doi: 10.1901/jaba.2010.43-487. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Schepis TS, Duhig AM, Liss T, McFetridge A, Wu R, Cavallo DA, Krishnan-Sarin S. Contingency management for smoking cessation: Enhancing feasibility through use of immunoassay test strips measuring cotinine. Nicotine & Tobacco Research. 2008;10:1495–1501. doi: 10.1080/14622200802323209. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Singh T, Arrazola RA, Corey CG. Tobacco use among middle and high school students – United States, 2011–2015. Morbidity and Mortality Weekly Report (MMWR) 2016;65:361–367. doi: 10.15585/mmwr.mm6514a1. http://dx.doi.org/10.15585/mmwr.mm6514a1. [DOI] [PubMed] [Google Scholar]
  19. Smith A. Smartphone adoption and usage. Pew Research. 2011 Retrieved from. [Google Scholar]
  20. Sobell LC, Sobell MB. Timeline follow-back: a technique for assessing self-reported alcohol consumption. In: Litten RZ, Allen JP, editors. Measuring Alcohol Consumption. New York: Humana Publisher; 1992. pp. 41–72. [Google Scholar]
  21. Stitzer M, Petry NM. Contingency management for treatment of substance abuse. Annual Review of Clinical Psychology. 2006;2:411–434. doi: 10.1146/annurev.clinpsy.2.022305.095219. https://doi.org/10.1146/annurev.clinpsy.2.022305.095219. [DOI] [PubMed] [Google Scholar]
  22. Stoops WW, Dallery J, Fields NM, Nuzzo PA, Schoenberg NE, Martin CA, Wong CJ. An Internet-Based Abstinence Reinforcement Smoking Cessation Intervention in Rural Smokers. Drug and Alcohol Dependence. 2009;105(1–2):56–62. doi: 10.1016/j.drugalcdep.2009.06.010. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Sussman S. Effects of sixty six adolescent tobacco use cessation trials and seventeen prospective studies of self-initiated quitting. Tobacco Induced Diseases. 2002;1(1):35–81. doi: 10.1186/1617-9625-1-1-35. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Sussman S, Sun P. Youth tobacco use cessation: 2008 update. Tobacco Induced Diseases. 2009;5(3) doi: 10.1186/1617-9625-5-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Sussman S, Sun P, Dent CW. A meta-analysis of teen cigarette smoking cessation. Health Psychology. 2006;25:549–557. doi: 10.1037/0278-6133.25.5.549. [DOI] [PubMed] [Google Scholar]
  26. Tevyaw TO, Colby SM, Tidey JW, CW K, Rohsenow DJ, Barnett NP, Monti PM. Contingency management and motivational enhancement: A randomized clinical trial for college student smokers. Nicotine & Research Tobacco. 2009;11:739–749. doi: 10.1093/ntr/ntp058. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Wiehe SE, Garrison MM, Christakis DA, Ebel BE, Rivara FP. A systematic review of school-based smoking prevention trials with long-term follow-up. Journal of Adolescent Health. 2005;36:162–169. doi: 10.1016/j.jadohealth.2004.12.003. [DOI] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

1
NIHMS910334-supplement-1.docx (98.7KB, docx)

RESOURCES