Abstract
Importance e-Cigarettes are the most commonly used tobacco product among young adults (YAs). Despite the harms of nicotine exposure among YAs, there are few, if any, empirically tested vaping cessation interventions available.
Objective To determine the effectiveness of a text message program for vaping cessation among YAs vs assessment-only control.
Design, Setting, and Participants A parallel, 2-group, double-blind, individually randomized clinical trial was conducted from December 2019 to November 2020 among YA e-cigarette users. Eligible individuals were US residents aged 18 to 24 years who owned a mobile phone with an active text message plan, reported past 30-day e-cigarette use, and were interested in quitting in the next 30 days. Participants were recruited via social media ads, the intervention was delivered via text message, and assessments were completed via website or mobile phone. Follow-up was conducted at 1 and 7 months postrandomization; follow-up data collection began January 2020 and ended in November 2020. The study was prespecified in the trial protocol.
Interventions All participants received monthly assessments via text message about e-cigarette use. The assessment-only control arm (n = 1284) received no additional intervention. The active intervention arm (n = 1304) also received a fully automated text message program for vaping cessation that delivers social support and cognitive and behavioral coping skills training.
Main Outcomes and Measures The primary outcome was self-reported 30-day point prevalence abstinence (ppa) at 7 months analyzed under intention-to-treat analysis, which counted nonresponders as vaping. Secondary outcomes were 7-day ppa under intention-to-treat analysis and retention weighted complete case analysis of 30-day and 7-day ppa.
Results Of the 2588 YA e-cigarette users included in the trial, the mean (SD) age was 20.4 (1.7) years, 1253 (48.4%) were male, 2159 (83.4%) were White, 275 (10.6%) were Hispanic, and 493 (19.0%) were a sexual minority. Most participants (n = 2129; 82.3%) vaped within 30 minutes of waking. The 7-month follow-up rate was 76.0% (n = 1967), with no differential attrition. Abstinence rates were 24.1% (95% CI, 21.8%-26.5%) among intervention participants and 18.6% (95% CI, 16.7%-20.8%) among control participants (odds ratio, 1.39; 95% CI, 1.15-1.68; P < .001). No baseline variables moderated the treatment-outcome relationship, including nicotine dependence.
Conclusions and Relevance Results of this randomized clinical trial demonstrated that a tailored and interactive text message intervention was effective in promoting vaping cessation among YAs. These results establish a benchmark of intervention effectiveness.
Introduction
Electronic cigarettes (e-cigarettes) are the most commonly used tobacco product among US young adults (YAs) aged 18 to 24 years.1 Data from the US Centers for Disease Control and Prevention show that e-cigarette use (every day or some days) among YAs increased from 5.2% in 2014 to 9.3% in 2019,1,2 with more than half (56%) of YA e-cigarette users reporting that they have never smoked cigarettes. The majority of e-cigarettes contain nicotine, and concentrations available in popular products have increased over the past decade.3 Indeed, nicotine consumption and exposure can be extremely high among YA e-cigarette users.4–6 Nicotine has negative health effects on brain development occurring into the mid-20s,7 including nicotine addiction, mood disorders, permanent lowering of impulse control, and deficits in attention and learning.8 Additionally, the aerosol produced by e-cigarettes contains known carcinogens and tiny particles that reach deep into the lungs.9 The effects of long-term exposure to these chemicals remain unknown. e-Cigarette use among young adults has been associated with future initiation of combustible tobacco use10 and with increased odds of alcohol and marijuana use.11
Responding to calls for research on e-cigarette cessation interventions,12,13 this study examined the effectiveness of a text message program for vaping cessation in a randomized clinical trial among YAs. Mobile phone ownership is ubiquitous among YAs,14 and text messaging is easy to use, discreet, anonymous, and a preferred communication modality in this age group.15 Text messaging has also been shown to be an effective intervention strategy for smoking cessation.16–18 The primary hypothesis was that participants in the active intervention arm would be more likely to be abstinent at the 7-month post-randomization primary end point than participants in an assessment-only control arm. We also examined whether any demographic, psychosocial, or substance use characteristics moderated the effectiveness of the intervention, with a particular focus on nicotine dependence as an a priori construct of interest given its well-established association with lower odds of tobacco cessation.19
Results
Between December 29, 2019, and March 18, 2020, 11 080 individuals were screened for eligibility and 2588 participants were randomized (1284 to the control arm and 1304 to program). At 1 month, the response rate was 79.5% (n = 2057 of 2588), with slightly higher retention rates in the control arm vs the program (81.4% [n = 1045 of 1284] vs 77.6% [n = 1012 of 1304], respectively; P = .02; SMD = 0.09). At 7 months, the response rate was 76.0% (n = 1967 of 2588), with no difference between the control and program arms (77.4% [n = 994 of 1284] vs 74.6% [n = 973 of 1304], respectively; P = .11; SMD = 0.06; Figure).
The mean (SD) age of the 2588 participants was 20.4 (1.7) years (Table 1). Of the total sample, 1253 (48.4%) were male, 2159 (83.4%) were White, 275 (10.6%) were Hispanic, and 493 (19.0%) were a sexual minority. Roughly one-third (n = 915 [35.4%]) reported barely or not meeting basic expenses. Three-quarters of the sample (n = 1932 [74.7%]) were current students. The majority of participants (n = 2410 [93.1%]) vaped nicotine daily, and 2129 (82.3%) reported vaping within 30 minutes of waking. Participants reported a strong desire to quit vaping (mean [SD], 4.54 [0.70]) but were less confident about their ability to quit (mean [SD], 3.47 [1.15]). Most (n = 2366 [91.4%]) had tried to quit in the past year, and 1692 (65.4%) had made 3 or more quit attempts. Past 30-day use of other substances was as follows: cigarettes, 32.5% (n = 841); marijuana/cannabis, 59.3% (n = 1534); and binge drinking, 74.5% (n = 1929). More than one-third (n = 910 [35.2%]) had a positive screen for depression on the PHQ-2, and 1134 (43.8%) had a positive screen for anxiety on the Generalized Anxiety Disorder-2; 1317 (50.9%) had a positive screen on either measure. No between-arm differences exceeded an SMD of 0.2, indicating a balanced sample with no clinically meaningful differences between arms.
Vaping Cessation
As shown in Table 2, 30-day ppa rates at 7 months under ITT were 24.1% (n = 314 of 1304) among TIQ participants and 18.6% (n = 239 of 1284) among controls. A comparison of baseline characteristics between 7-month responders and nonresponders showed that race (SMD = 0.25) and student status (SMD = 0.26) exceeded the threshold for a small effect (eTable 1 in Supplement 2). A multivariate logistic regression model with 7-month response status as the outcome identified Hispanic ethnicity, sexual minority status, current student status, and PHQ-2 score as predictors of study retention, with current student status and PHQ-2 score resulting in nondifferential attrition by study arm. The IPRW analyses of 7-month outcomes showed that the treatment benefit owing to TIQ in the odds ratio (OR) scale was broadly similar under ITT (OR, 1.39; 95% CI, 1.15-1.68; P < .001) and IPRW (OR, 1.51; 95% CI, 1.24-1.85; P < .001) analyses. Table 2 also shows 7-day ppa under IPRW and ITT analyses; program yielded higher quit rates than control under both analytic approaches, though effect sizes were smaller than those for 30-day ppa. Sensitivity analyses based on multiple imputation modeling confirmed the robustness of ITT estimates (eAppendix 2 and eTable 2 in Supplement 2).
Moderator Results
Analyses of all variables in Table 1 as potential moderators of treatment effects on 30-day ppa rates under both ITT and IPRW analysis yielded no statistically significant findings (eTable 3 in Supplement 2). In stratified analyses focused on time to first vape, ITT abstinence rates among those who reported vaping within 30 minutes of waking were slightly lower in both study arms but still favored program over control (22.6% vs 16.4%; P < .001). Among those who reported vaping 30 minutes after waking, ITT abstinence rates were higher in both study arms with no difference between program and control (31.4% vs 28.6%; P = .51).
Intervention Satisfaction
As shown in Table 3, program participants reported higher levels of intervention satisfaction compared with control participants across all items. The largest effect size (SMD = 0.668) was observed for the item “They suggested quitting strategies that were new to me.” Three items were of small-moderate magnitude: (1) “They made me feel that I knew the right steps to take to quit” (SMD = 0.347), (2) “They made me feel less alone in quitting” (SMD = 0.344), and (3) “They helped me feel more confident about quitting” (SMD = 0.224).
