Testing a School-Based E-cigarette, Tobacco, and Betel (Areca) Nut Use Prevention Curriculum for Guam Youths
Condition: Tobacco Smoking; Vaping; Tobacco Chewing
Study type: Interventional

Summary: 
      The people of the U.S. Affiliated Pacific Islands (USAPI) face higher cancer incidence,
      especially lung/bronchia and head-and-neck cancer, and poorer cancer outcomes, compared with
      the U.S. nationally. This may partly be driven by the high rates of cigarette smoking and
      betel (areca) nut use in the USAPI. Previous data suggest that that adolescents on Guam, as
      young as middle school students report markedly higher e-cigarette and tobacco product use
      prevalence in the USAPI compared with the USAPI nationally. Guam youths are also at risk for
      the use of betel nuts. Yet, currently there are no tobacco product/areca nut use prevention
      programs that have been developed for and tested specifically USAPI adolescents. The proposed
      study will develop a school-based substance use prevention curriculum for e-cigarette,
      tobacco product, and areca nut use prevention among Guam youths. The curriculum will use
      lessons incorporating innovative videos and culturally grounded activities.

      The study's specific aims are:

        1. To develop a school-based curriculum for e-cigarette, tobacco product (i.e., cigarette,
           smokeless tobacco), and betel nut use prevention among middle school students in Guam.

        2. Test the efficacy of the school-based curriculum in a randomized controlled trial.
    

Detailed description: 
      BACKGROUND AND SIGNIFICANCE

      The study focuses on e-cigarette, tobacco and areca nut prevention among adolescents in Guam.
      By developing and testing a school-based e-cigarette, tobacco and areca nut prevention
      program, the project will target psychosocial, lifestyle, and environmental/physical factors
      contributing to cancer disparities in the US Affiliated Pacific Islands (USAPI). Thus far,
      nationally, there has been limited effort in terms of developing a theoretical framework that
      would attempt to explain tobacco and areca nut use etiology among USAPI youth. Previous
      research indicates that social and environmental influences play key roles in shaping tobacco
      and areca nut use among USAPI youths. In addition, skills needed to resist social influence
      appear to be protective against tobacco and areca nut use. Particularly, past research has
      found peer influence and environmental risk factors such as parental permissiveness, ease of
      access to tobacco/areca nut at home and school and through adults and friends, to be strongly
      associated with current tobacco/areca nut use. On the other hand, competence in navigating
      through social situations conducive to tobacco/areca nut use and refusal self-efficacy (i.e.,
      confidence in being able to say "no" at the face of peer pressure) have been found to be
      strongly associated with lower likelihood of current tobacco/areca nut use.

      The curriculum to be developed and tested will focus on informing adolescents on the risks of
      tobacco product/areca nut use as well as training adolescents on social influence resistance
      skills in a culturally appropriate way, using innovative use of video vignettes. The
      intervention will seek to influence behavior (i.e., prevention and reduction of tobacco
      product/areca nut use) by countering the cognitive predispositions to tobacco product/areca
      nut use (e.g., by increasing risk perceptions, reducing positive expectancies) and by
      providing youths with skills to resist specific social influence to use tobacco
      products/areca nut on specific occasions.

      RESEARCH DESIGN

      This is an experimental study. Of the eight public middle schools in Guam, four schools will
      be randomly assigned to the "Treatment" and four to the "Control" condition. Students in the
      Treatment schools will receive the classroom-based curriculum whereas students in the Control
      schools will receive the standard health education curriculum (treatment-as-usual).
      Participants will be assessed at pre-test, immediate post-test, and six months after the
      post-test. Note that the decision to provide an intervention, albeit weaker, to the control
      group was guided by the ethics of good community practice. In preliminary discussions with
      schools, principals unanimously expected an intervention.

      Participants

      Participants will be 600 Guam middle school students. Based on a pilot study, the mean age of
      the participants is likely to be 12.7 years (SD = .89); 49% of the participants are likely to
      be girls; and 47% of the participants are likely to be Chamorus, 27% other Pacific Islanders,
      and 25% non-Pacific Islanders (i.e., Filipinos, Chinese, Japanese, white, and others).
      Treatment and Control conditions will represent roughly equal proportion of participants.

      Recruitment

      All eight public middle schools will be involved in the study. The Guam Department of
      Education (GDOE) has been very supportive of this study. At each school, seven classes will
      be randomly selected to participate in the study.

      Intervention delivery

      The classroom curriculum will begin in the Treatment schools within two weeks of the
      pre-test. The social media campaign will begin in all schools around the same time. Below we
      provide details on the delivery of each intervention component.

      Classroom-based curriculum: Curriculum implementation. The curriculum will be delivered by
      teachers of the Treatment schools who normally teach physical health education classes. The
      curriculum will be implemented once a week for 45-60 minutes over a 10-week academic quarter
      in a required physical/health education course. All sessions of the curriculum will follow
      the same basic format of Ho'ouna Pono. Each lesson will be aligned with the Guam Content and
      Performance Standards for Health (6-8 grade) and/or the National Common Core Standards in
      public education. The teachers will be trained to implement the curriculum through a hybrid
      (i.e., in-person and virtual), credit-granting course sanctioned through the GDOE.

      Data collection

      Data will be collected at three timepoints from students in both Treatment and Control
      conditions: pre-test (baseline), immediate post-test (i.e., approximately a week after the
      last classroom-based curriculum session is delivered), and six months after the post-test.
      Data will be collected using self-report questionnaires, although self-report of cigarette
      use and areca nut use will also be validated using biochemical verification methods in random
      subsample of participants. At each timepoint the same questionnaire will be administered
      across Treatment and Control groups. The self-report questionnaire will include the following
      assessment measures.

      Measures

      Demographic measures. Age, gender, socio-economic status, and ethnicity will be assessed.
      Socio-economic status (SES) is measured based on participants' report on their parents' level
      of education. However, past research shows that a good proportion of adolescents do not know
      about parental education level. Hence, a measure of household crowdedness (i.e., the number
      of usual residents in a household divided by the number of rooms in the house) will also be
      included to assess SES. Ethnicity will be assessed with a single item previously used by us
      in Guam. A measure of acculturation will also be included.

      Intrapersonal/Dispositional variables. These will include self-control, assessed in terms of
      behavioral and emotional self-control; sensation seeking; social competence in resisting
      social influence; general self-efficacy; refusal self-efficacy; and self-esteem. The items
      specific to substance use will be adapted for cigarette smoking, e-cigarette use, chewing
      tobacco use, and areca nut use.

      Social/Interpersonal variables. These will include family and friend areca nut/tobacco
      product use, perceived norms, and social normative beliefs. Perceived norms and social
      normative beliefs will be adapted for cigarette smoking, e-cigarette use, chewing tobacco
      use, and areca nut use.

      Cultural/Environmental variables. These will include availability of areca nut/tobacco at
      home and school, parental permissiveness, knowledge about areca nut/tobacco products, areca
      nut/tobacco product use expectancies, and areca nut/tobacco product use harm/risk
      perceptions.

      Exposure to content relevant to tobacco products and areca nut on social media. Exposure will
      be assessed using 12 items previously validated by us for tobacco products and areca nut. The
      items assess exposure to user-generated content, traditional marketing, and prevention
      messages.

      Areca nut and tobacco product use susceptibility. Areca nut use and tobacco product use
      susceptibility will be separately assessed for cigarette smoking, e-cigarette use, chewing
      tobacco use, and areca nut use with a measure of adolescent substance use intentions (13),
      adapted for each substance.

      Areca nut and tobacco product use. The study will assess areca nut only use, combined areca
      nut and tobacco use, cigarette smoking, e-cigarette use, and chewing tobacco use separately.
      For each of these substance use outcomes, the study will assess lifetime (ever) use (e.g.,
      "Have you ever used a areca nut in your lifetime?") and past-30-day use (e.g., "In the past
      30 days, on how many days did you use areca nut?). Self-report measures of adolescent
      substance use have been extensively studied for their validity, by using multiple methods,
      and they have consistently been found to be valid.

      Data Analysis

      Data analysis will be performed with the help of the PIPCHE Biostatistics Core. The primary
      goal of the analysis is to examine the efficacy of this group randomized trial (16) for
      substance use prevention among middle schoolers. Aim 1 will compare the change in tobacco and
      areca nut beliefs, attitudes, initiation and use over time between the two randomization
      conditions, accounting for the clustering of classes within schools and the randomization
      unit of schools. In particular, the following mixed regression will be performed: where Z is
      a vector of covariates for each student at each time point, T is time, G is randomization
      group, TxG is the interaction of time and group, and η is a random effect for clustering of
      classes within schools and δ is a random effect for repeated measures within student. The
      link function ƒ is linear for continuous outcomes, such as a belief score, and logistic for
      dichotomous outcomes, such as initiation; outcomes will be transformed as needed to meet
      model assumptions. Potential covariates would include age, sex of student, grade, ethnicity,
      parent's education level, sensation seeking and teacher sex. Time T will be parameterized as
      indicator variables for baseline, post-intervention, and six month follow-up, or as
      continuous months if warranted by a monotonic change over time. The intervention effect will
      be assessed by the F-test in linear models and chi-square test in logistic models for the βTG
      parameter, with the degrees of freedom adjusted to account for the eight randomization units.
      Covariate-adjusted means and 95% confidence intervals will be estimated from the models for
      each level of randomization group and time point. The SAS procedure GLIMMIX will be used to
      fit these mixed models, which can accommodate data from students with missing data at some
      time points and allow for the results to be more generalizable to the student population.
      However, the study will assess the effect of missing data by comparing characteristics of
      students with complete and incomplete data and will perform multiple imputation if needed. As
      exploratory analyses, the study will test for differential intervention effects in subgroups,
      such as defined by student ethnicity, by adding interaction terms between subgroup and
      treatment/time variables and assessing the significance of the three way interaction. The
      study will also explore the effect of dose of the intervention, by studying change in
      outcomes by number of session attended among students in the intervention schools, and the
      effect of fidelity assessments of the intervention per classroom.

      Statistical Power

      The sample size of eight schools, with four randomized to each condition, each with seven
      classes of 20 students, is sufficient to ensure adequate statistical power to detect
      meaningful differences between intervention arms in all outcomes. For Aim 1, the effect size,
      Cohen's d was calculated based on a z-test comparing means and a chi-square test comparing
      proportions, with n=8 schools, with four schools per randomization condition, each with 20
      students. The variance of the differences was adjusted for the Design Effect of the present
      study, accounting for the clustering in a group-randomized trial (GRT) by adjusting the test
      degrees of freedom to the number of communities. The intraclass correlation coefficient (ICC)
      of outcomes within schools and within class in schools was set to 0.01-0.02, based on past
      school-based studies, for an overall ICC varying between 0.02 to 0.04. The study assumed a
      critical level α of 0.05 (two-sided) or 0.005 (Bonferroni-corrected for 10 tests), a power of
      80%, and up to a 20% attrition in sample size at post-intervention. The effect size for a
      test of means is medium at 0.29-0.38 for α=0.05 and at 0.37-0.50 for α=0.005. The following
      differences between conditions in changes in proportions will be detectable with α=0.05: 0%
      versus 4.0% and 3% versus 10.5%; and with α=0.005: 0% versus 6.5% and 3% versus 15.5%.
    

Intervention name(s): School-based curriculum
Intervention type(s): Behavioral
Intervention description(s): Participants will be randomized, at the school level, to receive either the e-cigarette/tobacco/areca nut use prevention curriculum or the standard of care (i.e., control). The curriculum will be implemented using 5 intensive in-class lessons over the span of 6 weeks. All sessions of the curriculum follow the same basic format: a) an introduction and/or review of the past lesson, b) a cultural wall activity, c) a video, d) 1-2 interactive activities, and e) a wrap-up activity. Lessons are designed such as to help improve knowledge about drugs and correct cognitive misperceptions and to train on skills to resist normative social influence. Participants will complete identical survey questionnaires for assessments at 3 time-points: pretest (baseline, before implementing the intervention), immediate posttest (following the end of the intervention), and six-month follow-up. The surveys will be administered in the classroom, during regular school hours.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: tobacco; e-cigarette; Areca nut; Prevention; Adolescents