A Mobile-phone Based Intervention to Support Smoking Cessation Among Chilean Women
Condition: Smoking Cessation
Study type: Interventional

Summary: 
      The purpose of this study is to determine whether a mobile-phone based intervention is
      effective in supporting smoking cessation among Chilean women
    

Detailed description: 
      This protocol corresponds to a single-blind, two-arm, randomized clinical trial of a smoking
      cessation intervention based on a mobile-phone app. Eligible participants are Chilean women
      from the Metropolitan Region, who smoke daily (at least one cigarette per day) or weekly (at
      least 7 cigarettes per week), and who are willing to make a quit attempt within one month of
      enrollment. Study will be advertised on the local radio, primary care centers, smoking
      cessation services and through social media campaigns. Study information will be available
      online. Potential participants will be asked to register their interest by sending an email
      to the study. Research assistants then will contact respondents by phone in order to complete
      a baseline questionnaire about sociodemographic variables, characteristics of tobacco
      consumption, and to assess eligibility for the study. Eligible participants will be then
      randomized to the intervention group or control group using a computerized and automated
      process, in blocks of 6. A minimization algorithm balancing for Fagerstrom score for nicotine
      addiction (≤5, >5) will be used. Researchers who will gather data and those who will measure
      carbon monoxide in exhaled air will be masked to treatment allocation.

      Each participant will be emailed the link with either the intervention or the control version
      of the mobile-phone app. Once participants download the app, they will be asked to provide
      informed consent by clicking the "accept" or "reject" button in the app.

      Participants randomized to the intervention app will be sent motivational and preparatory
      content for the first two weeks, and they will be asked to set a quit date within 4 weeks
      from enrollment. The mobile app will send an average of 4 messages per day during the first
      month after quit date, followed by three messages per week up to the end of the study at
      month 6.

      The intervention program was designed based on current best evidence on strategies to support
      smoking cessation, and included work of Chilean experts in smoking cessation. The design of
      the intervention app also included the opinion and preferences of potential participants who
      participated in focus groups during intervention design. The intervention app includes
      motivational messages, tips on stress management, on how to ask support from friends and
      family, how to use distraction techniques and how to deal with cravings, lapses and early
      relapse.

      The intervention app also includes a "help button" which provides extra messages in case of
      cravings and a "lapse/relapse button", which provides advice about what to do if the
      participant returned to smoke. The control group will receive a control app which will send 1
      message every two weeks thanking participants for taking part in the study, and encouraging
      them to stay in the study for the 6 month follow-up period. After completing the 6-month
      follow-up evaluation, the control group will be offered access to the intervention app.

      Women will not receive financial compensation for their participation in the study. In order
      to increase retention, participants in both arms will be told that they would be entered into
      a lottery for different prizes after answering the 6-month follow-up questionnaire.

      For the 4-week, 3-month and 6-month follow-up, a link to an electronic follow-up
      questionnaire will be emailed to all participants. Reminders will be sent to non responders
      and if they still do not respond, additional email reminders will be sent. If participants
      still do not respond, research assistants will call them by phone in order to capture the
      primary outcome of the study. At 6-month follow-up, participants who reported having quit
      smoking will be asked to attend to the local primary care center in order to measure carbon
      monoxide in exhaled air. All measurements will be performed by research assistants who are
      masked to treatment allocation.

      Sample size was calculated based on previous studies. Twenty-eight percent quitting in the
      intervention group and 13% in the control group was expected. To achieve 90% power with a
      significance level of P ≤ .05 (2-sided), and including a 20% attrition for the 6 month
      follow-up evaluation, a sample size of 400 was estimated. In order to take into account that
      the size effect associated to the intervention could be lesser in Chile than the reported for
      other countries, investigators defined a 90% power for the sample size calculation.

      Investigators plan to conduct analyses for the whole sample and also for subgroups of age
      (<35 years, ≥35 years), nicotine addiction (Fagerstrom score ≤5, >5), educational level (<8
      years, 8-12 years, ≥12 years), and use of other smoking cessation treatments or services
      during the trial (yes, no).

      All statistical analyses for clinical effectiveness will be undertaken on an
      intention-to-treat basis. For missing observations in the primary outcome, two methods will
      be used: last value carried forward method and multiple imputation method, as attempts to
      correct for potential bias caused by missing data.

      Analyses for adverse effects outcomes will be performed on a per-protocol basis.
    

Intervention name(s): Mobile-phone app for smoking cessation
Intervention type(s): Behavioral
Intervention description(s): Android App for smoking cessation
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Two-arm, randomized clinical trial of a smoking cessation intervention based on a mobile-phone app. Participants will be randomly assigned to the intervention group or control group, in parallel for the duration of the study (6 months follow-up).
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Cell phones; Women