Project Overview +

Project Quit is a web-based program to help individuals who are in the "Preparation Stage" (ready to quit smoking within 30 days) to quit smoking. The overall goal of the study is to identify optimal population-based health communications strategies tailored to specific characteristics of the individual. This project will focus on identifying and specifying active psychosocial and communication components or "factors" of smoking cessation interventions.

Aims +

Phase I:

Aim 1. Using a fractional factorial design, screen for the effects of six potentially active psychosocial and communication components of web-based smoking cessation interventions: message content, message framing, exposure schedule, use of testimonials, and message source.

Aim 2. Investigate how psychosocial and communication component effects are moderated by relevant characteristics of the individual (e.g., stage of change; baseline level of motivation and self-efficacy; barriers, need for cognition; health locus of control; and socio-demographics and health status).

Phase II:

Aim 1. In follow-up experiments with a new sample, refine our understanding of how the active psychosocial and communication components identified in Phase I influence the primary outcome variables by manipulating factor levels and factors related to the screened component.

Aim 2. Refine and further explore root causes for promising interactions between psychosocial and communication components, and specific individual characteristics.

Participants +

4,000 smokers in 3 Cancer Research Network HMOs

Intervention +

Phase I: Uses a fractional factorial design to identify the active psychosocial and communication components of web-based smoking cessation interventions: message content, message depth, message framing, exposure schedule, use of testimonials, and message source. It also investigates how psychosocial and communication component effects are moderated by relevant characteristics of the individual (e.g., baseline level of motivation and self-efficacy; barriers, need for cognition; health locus of control; and socio-demographics and health status).

Participants are recruited from Group Health (GH) of Seattle, Washington, HealthPartners (HP) of Minneapolis, Minnesota, and the Henry Ford Health System's Health Alliance Plan (HFHS) of Detroit, Michigan.

Participants are randomized into one of 16 study arms. All participants receive a web-based guide to help them quit smoking, along with a free 10-week supply of nicotine replacement therapy patches. Email messages are sent to participants about various aspects of the program, including patch use and step down process, and the availability of new web guide materials.

Phase II:

In follow-up experiments with a new sample from the same HMOs, Phase II refines our understanding of the active psychosocial and communication components identified in Phase I.

Phase II explores Message Source and the use of Testimonials. Whereas message source and testimonials were only a small part of Phase I, each of the six web components in Phase II contains a testimonial and a manipulated message source. Phase II also varies the characters portrayed in the testimonials. Participants receive testimonials from one of three character types (Caregiver, Rebel, Self-made). Analysis explores relationships between character types, participant characteristics, program satisfaction, and cessation rates.

Findings +

Phase I Findings:

To test the impact of tailoring depth, smokers were assigned to receive between 0 and 3 high-depth tailored cessation intervention components (success stories, outcome expectations, and efficacy expectations). Tailoring depth was significantly related to 6-month smoking cessation using per-protocol analysis, both across the entire range of cumulative high-depth components (OR1.91; CI1.18 3.11) and for each high-depth component added (OR1.24; CI1.06 1.45). Tailoring depth was marginally related (p0.08) to smoking cessation in the complete respondent and ITT analyses. Adjusted 6-month cessation rates among participants receiving all three high-depth tailored components were 38.6% in the per-protocol analysis, 37.9% in the complete respondent analysis, and 27.7% in the ITT analysis.

  • Abstinence was most influenced by high-tailored success stories (testimonials) and high-personalized message source (source letter).
  • Cumulative assignment of the three tailoring depth factors (message source, testimonial, and efficacy) also resulted in increasing rates of six-month cessation, demonstrating an effect of tailoring depth.
  • Greater engagement with a web-based smoking cessation program results in greater subsequent cessation.
  • The depth of tailoring in smoking cessation messages results in greater perceptions of message relevance, which, in turn, results in greater engagement with a web-based smoking cessation program.
  • A significant number of smokers can be recruited through Health Maintenance Organizations (HMOs) for web-based smoking cessation interventions.
  • African Americans with a large number of people supporting their quit efforts were greater than two times more likely to quit than those with few or no supporters, regardless of tailoring intensity.

Phase II Findings:

Re-examining the best of Phase I program materials, Phase II had similar quit rates as the highly tailored Phase I component.

Conclusion +

The study identified relevant components of smoking cessation interventions that should be generalizable to other cessation interventions. The study also demonstrates the importance of higher-depth tailoring in smoking cessation programs. Finally, the fractional factorial design allowed efficient examination of the study aims. The rapidly changing interfaces, software, and capabilities of eHealth are likely to require such dynamic experimental approaches to intervention discovery.