Abstract

The sizeable percentage of adults who use smokeless tobacco (ST) represents an important public health target since the majority of ST users have a strong desire to quit, but many lack resources. We tested the impact of an interactive, tailored Web-based intervention (Enhanced Condition) versus a more linear, text-based website (Basic Condition) in a randomized trial with 2523 adult ST users. As is common in Internet-based research, there was considerable attrition: follow-up rates at 3 months, 6 months, and for both 3 and 6 months were 48%, 45% and 34%, respectively. Results using repeated point prevalence of all tobacco use at 3 and 6 months showed that participants in the Enhanced Condition quit at significantly higher rates than those in the Basic Condition. Using a Complete Case analysis, abstinence was 40.6% in the Enhanced Condition vs. 21.2% in the Basic Condition (p< .001). Using intent-to-treat analysis, quit rates were 12.6% vs. 7.9%, respectively (p< .001). Similar results were obtained for only ST use. Unobtrusive measures of program exposure indicated that program use was significantly related to outcome as well as to attrition. We conclude that a tailored, interactive Web-assisted cessation program can be an efficacious method for assisting adult ST users to quit.

Abstract

BACKGROUND:

Web-based behavioral intervention research is rapidly growing.

PURPOSE:

We review methodological issues shared across Web-based intervention research to help inform future research in this area.

METHODS:

We examine measures and their interpretation using exemplar studies and our research.

RESULTS:

We report on research designs used to evaluate Web-based interventions and recommend newer, blended designs. We review and critique methodological issues associated with recruitment, engagement, and social validity.

CONCLUSIONS:

We suggest that there is value to viewing this burgeoning realm of research from the broader context of behavior change research. We conclude that many studies use blended research designs, that innovative mantling designs such as the Multiphase Optimization Strategy and Sequential Multiple Assignment Randomized Trial methods hold considerable promise and should be used more widely, and that Web-based controls should be used instead of usual care or no-treatment controls in public health research. We recommend topics for future research that address participant recruitment, engagement, and social validity.

Abstract

An estimated 22% of Americans currently use smokeless tobacco (ST). Most live in small towns and rural areas that offer few ST cessation resources. Approximately 94 million Americans use the Internet for health-related information, and on-line access is growing among lower-income and less-educated groups. As part of a randomized clinical trial to assess the reach and effectiveness of Web-based programs for delivering an ST cessation intervention, the authors developed and evaluated several methods for overcoming the recruitment challenges associated with Web-based research. This report describes and evaluates these methods. Participants were recruited through: (a) Thematic promotional "releases" to print and broadcast media, (b) Google ads, (c) placement of a link on other Web sites, (d) limited purchase of paid advertising, (e) direct mailings to ST users, and (f) targeted mailings to health care and tobacco control professionals. Combined recruitment activities resulted in more than 23,500 hits on our recruitment website from distinct IP addresses over 15 months, which yielded 2,523 eligible ST users who completed the registration process and enrolled in the study. Self-reports revealed that at least 1,276 (50.6%) of these participants were recruited via mailings, 874 (34.6%) from Google ads or via search engines or links on another Web site, and 373 (14.8%) from all other methods combined. The use of thematic mailings is novel in research settings. Recruitment of study participants went quickly and smoothly. Google ads and mailings to media outlets were the methods that recruited the highest number of participants.

Abstract

BACKGROUND:

Published research on the use of Web-based behavior change programs is growing rapidly. One of the observations characterized as problematic in these studies is that participants often make relatively few website visits and spend only a brief time accessing the program. Properly structured websites permit the unobtrusive measurement of the ways in which participants access (are exposed to) program content. Research on participant exposure to Web-based programs is not merely of interest to technologists, but represents an important opportunity to better understand the broader theme of program engagement and to guide the development of more effective interventions.

OBJECTIVES:

The current paper seeks to provide working definitions and describe initial patterns of various measures of participant exposure to ChewFree.com, a large randomized controlled trial of a Web-based program for smokeless tobacco cessation.

METHODS:

We examined measures of participant exposure to either an Enhanced condition Web-based program (interactive, tailored, and rich-media program) or a Basic condition control website (static, text-based material). Specific measures focused on email prompting, participant visits (number, duration, and pattern of use over time), and Web page viewing (number of views, types of pages viewed, and Web forum postings).

RESULTS:

Participants in the ChewFree.com Enhanced condition made more visits and spent more time accessing their assigned website than did participants assigned to the Basic condition website. In addition, exposure data demonstrated that Basic condition users thoroughly accessed program content, indicating that the condition provided a meaningful, face-valid control to the Enhanced condition.

CONCLUSIONS:

We recommend that researchers conducting evaluations of Web-based interventions consider the collection and analysis of exposure measures in the broader context of program engagement in order to assess whether participants obtain sufficient exposure to relevant program content.

Abstract

AIM:

To examine self-efficacy and program exposure as possible mediators observed treatment effects for a web-based tobacco cessation intervention.

DESIGN:

The ChewFree trial used a two-arm design to compare tobacco abstinence at both the 3- and 6-month follow-up for participants randomized to either an enhanced intervention condition or a basic information-only control condition.

SETTING:

Internet in US and Canada.

PARTICIPANTS:

Our secondary analyses focused upon 402 participants who visited the web-based program at least once, whose baseline self-efficacy rating showed room for improvement, who reported that they were still using tobacco at the 6-week assessment, and for whom both 3- and 6-month follow-up data were available.

INTERVENTION:

An enhanced web-based behavioral smokeless tobacco cessation intervention delivered program content using text, interactive activities, testimonial videos and an ask-an-expert forum and a peer forum. The basic control condition delivered tobacco cessation content using static text only.

MEASUREMENTS:

Change in self-efficacy and program exposure from baseline to 6 weeks were tested as simple and multiple mediators on the effect of treatment condition on point-prevalence tobacco abstinence measured at 3- and 6-month follow-up.

FINDINGS:

While both participant self-efficacy and program exposure satisfied the requirements for simple mediation, only self-efficacy emerged as a mediator when we used the more robust test of multiple mediation.

CONCLUSIONS:

Results confirm the importance of self-efficacy change as a probable underlying mechanism in a successful web-based behavioral intervention. While program exposure was found to be a simple mediator of tobacco abstinence, it failed to emerge as a mediator when tested with self-efficacy change in a multiple mediator test suggesting that self-efficacy and program exposure share a complex, possibly reciprocal relationship with the tobacco abstinence outcome. Our results underscore the utility of searching for mediators in research on web-based interventions.

Abstract

AIM:

To examine various methods to impute missing binary outcome from a web-based tobacco cessation intervention.

DESIGN:

The ChewFree randomized controlled trial used a two-arm design to compare tobacco abstinence at both the 3- and 6-month follow-up for participants randomized to either an enhanced web-based intervention condition or a basic information-only control condition.

SETTING:

Internet in the United States and Canada.

PARTICIPANTS:

Secondary analyses focused upon 2523 participants in the ChewFree trial.

MEASUREMENTS:

Point-prevalence tobacco abstinence measured at 3- and 6-month follow-up.

FINDINGS:

The results of this study confirmed the findings for the original ChewFree trial and highlighted the use of different missing-data approaches to achieve intent-to-treat analyses when confronted with substantial attrition. The use of different imputation methods yielded results that differed in both the size of the estimated treatment effect and the standard errors.

CONCLUSIONS:

The choice of imputation model used to analyze missing binary outcome data can affect substantially the size and statistical significance of the treatment effect. Without additional information about the missing cases, they can overestimate the effect of treatment. Multiple imputation methods are recommended, especially those that permit a sensitivity analysis of their impact.