Smoking tobacco is one of the most preventable causes of illness and premature death in the world [1
]. The development of effective smoking cessation programs is essential to prevent illnesses [2
One effective strategy for health promotion that has been developed during the last decades concerns computer-tailored interventions [3
]. CT has developed since the 1990s as a new technique for health promotion, as it provides the individual with personalized information and feedback on health behaviour. Tailored health messages are based on knowledge of a person generated from his or her answers to a questionnaire on issues related to health behaviour (in the case of smoking, for example, the perceived advantages of smoking and perceived support to quit smoking). Research has demonstrated that tailored communication attracts and keeps the individual's attention [5
]. Tailored information has furthermore been shown to be more likely to be read, remembered and considered personally relevant [6
]. CT programs can be either print delivered (delivered by post) or web-based. One advantage of web-based CT is that the user can follow the program in privacy at any preferred time [7
]. Furthermore, multimedia components can be incorporated and it has the potential to reach large audiences. CT is therefore increasingly offered by the web.
In the Netherlands, a range of empirical studies has demonstrated the efficacy of web-based computer-tailored programs compared with non-tailored programs for several lifestyle behaviours [6
] including smoking cessation [8
]. The effectiveness of computer-tailored technology to smoking cessation has been reviewed and tested in various studies [12
Smoking prevalence in Dutch people with a low socio-economic status (LSES) is higher than in people with a high socio-economic status (HSES) [14
]. People with a low SES also begin to smoke at an earlier age [15
] and have more difficulties in quitting [16
]. Several studies suggest that health communication probably needs to be different for LSES populations and suggest an approach with less cognitive effort [17
] that focuses more on visual than on text information [20
Consequently, the potential problem with CT smoking cessation programs is that they rely heavily on text-based messages and might therefore be less attractive to LSES smokers. Cognitive psychologists emphasize learning from more than one modality source, since humans actively process information with separate systems for visual and verbal representations [21
]. Several studies suggest that videos may be more effective in attracting attention and stimulating comprehension, especially in LSES smokers and smokers unmotivated to change [22
]. Video messages have been shown to require less mental effort and less translation of abstract concepts to create images [23
]. Findings using the Elaboration Likelihood Model suggest that LSES groups often do not process information deeply [20
]. Furthermore, research has identified that video presentation activates both visual and verbal channels, which together may lead to better learning outcomes [21
]. Whereas text messages require translation of abstract ideas to concrete situations, video messages may help to focus the recipient more on the basic message and help their understanding of the core message and reasons for engaging in the desired behaviour. Lower educated and motivated groups may thus profit in various ways from the utilization of videos and illustrations in smoking cessation programs.
To test the effectiveness of video-based messages it is important to use an experimental design in which the information provided by the videos is comparable to the text messages and a control condition. The video information should therefore use the same basic messages as the text version [24
]. Yet as far as we know no studies have been executed which test whether the use of video-based messages alone (without any other animation effects, like cartoons, hyperlinks, etc.) has an added effect on smoking cessation especially when targeting less literate groups. Also little attention has been given yet to the possible efficacy of video-based computer-tailored smoking cessation interventions targeting LSES smokers.
Besides method strategy it is also important to consider the dosage of CT. Research has demonstrated that multiple smoking cessation CT results in greater cessation effects than single tailored feedback letters [9
]. Similar effects have also been found for other behaviours than smoking, e.g. physical activity and dietary behaviour [7
]. Multiple tailoring feedback moments are therefore considered to be a useful strategy to implement for web-based computer-tailored smoking cessation programs as well.
The study whose protocol is described here aims to include these different elements by developing and testing two new e-health programs, incorporating multiple computer-tailored feedback moments. The two e-health programs differed only in the mode of delivery that was used (video- versus text-based messages).
The main aim of this paper is to describe the development of the two computer-tailored smoking cessation programs, their components and the design of the efficacy study.