This evaluation of the fully automated internet based smoking cessation intervention described herein has yielded promising results. The fully randomised control design lends confidence to the finding that the website intervention actually helped people stop smoking. The intent‐to‐treat analysis may have been excessively conservative as it is questionable to assume that all missing subjects are, in fact, smokers; however, even this conservative analysis showed significant intervention effects.
It is important to note several limitations to this study. First, all data are from self reports, and smoking status was not physiologically confirmed. Second, the attrition rate was quite high. Third, two findings are puzzling and inconsistent with other smoking cessation studies. In this study neither self efficacy nor number of cigarettes smoked per day was predictive of outcome. Despite repeated analyses using different approaches to data reduction and analysis, our data do not show an association between cessation outcome and measures of self efficacy or amount smoked per day. Fourth, longer follow up periods are needed to determine the long term impact of programmes such as this.
What this paper adds
Although numerous articles have been written about the promise of the internet for health education and behaviour change, most discuss only the potentials of the internet; relatively few have reported data from actual interventions and fewer have used fully controlled designs. The internet, which reaches a large and rapidly increasing number of people, has great potential as a means of providing behaviour change interventions to many people at low incremental cost. Thus, there is a need for studies that evaluate the actual impact of web based interventions.
The results from this randomised control trial of an entirely automated smoking cessation intervention, delivered via the internet, suggest that this type of intervention, with no direct personal contact of any kind, can be efficacious in helping people change their behaviour. Using a randomised control design, this study found more smokers were able to quit smoking when they used the website. Therefore, this study provides additional evidence that internet interventions can have a positive impact on health behaviours.
Because the attrition rate did not differ significantly across treatment and control groups, and the intent‐to‐treat analysis still showed significant effects, there is reason to have some confidence about these findings. However, improved retention rates would lend greater confidence in the generalisability of the findings. Interestingly, very high attrition rates have been found in other web based smoking cessation programme evaluations23
(R Munoz, personal communication, email 2 November 2002). The reasons for these high attrition rates could be related to: (1) the innate anonymity of internet contact, where users may feel no personal connection to intervention staff, thus perhaps lowering the motivation to quit; and (2) users' access to the internet or email addresses may change. Clearly, this is an area of importance for future studies.
One last concern is that although the treatment condition had significantly higher abstinence rates, both treatment and control condition quit rates were lower than might be expected in a group that is mostly in the contemplation or preparation stages of change.24
It is not clear why these rates are low. Perhaps people are more willing to declare themselves ready to quit in the next 30 days when they are in a completely anonymous situation and endorsing that position to a computer, not a person. Perhaps the emphasis on planning to quit (given concerns about the number of participants who would continue to return for assistance) rather than relapse prevention was misplaced. Further studies are needed to clarify the reasons for these findings if replicated.
Although there are limitations, the internet remains an attractive intervention tool because the incremental cost per user is negligible and the potential cost effectiveness is great. When viewed from the RE‐AIM perspective (Reach, Efficacy, Adoption, Implementation fidelity, and Maintenance) as described by Glasgow et al
this intervention may yield significant public health effects. The reach (that is, to anyone with a personal computer and a connection to the internet) is very large. The efficacy is reasonable for a single session, relatively “light touch” intervention, and is something that probably can be improved significantly. The adoptability is high as anyone (that is, worksites) with a website can include a link to the intervention site, and individual users can directly access the intervention via a computer with an internet connection. Perfect implementation fidelity is provided by the website itself. And lastly, maintenance costs are minimal for a programme such as this, once it has been developed. Thus, the overall potential public health value (R × E × A × I × M) is large. However, it must be noted that there often is a very large gap between potential reach and actual reach. The cost to achieve a given reach (and the time required to do so) may well be the impediment in implementing cost effective, efficacious internet interventions. In this study, despite recruitment at very large worksites, the number of enrolees per worksite was low and recruitment was slow, as has been observed in similar studies by others (R Munoz, personal communication, email 2 November 2002). How this affects the representativeness of the sample, and its generalisability, is unclear. Enrolment rates and retention are critical issues that must be addressed in future internet intervention studies.
In sum, the use of a completely automated intervention delivered via the internet resulted in elevated abstinence from cigarettes. This stands in contrast to other self administered interventions, such as self help manuals, which have minimal effectiveness when used alone.26,27
Although there are other strategies that might be employed for increasing the quit rates, such as using an online support group with a real moderator, this study indicates that it is possible to provide effective support with an automated system.