The global increase in the prevalence of chronic illness and the recognition that potentially modifiable health risk behaviours significantly contribute to this problem has resulted in a shift in the focus of health promotion interventions. A trend towards more wide-reaching public health interventions has become evident and the importance of behavioural science theories has been acknowledged. At the core of public health promotion emphasising change in health risk behaviours are community-based interventions. A substantial proportion of the burden of disease in Australia is accounted for by only a small number of health risk behaviours. In particular, cigarette smoking is responsible for the greatest burden of disease and is closely associated with alcohol use, physical inactivity and an unhealthy diet.
Investigation of the constructs which are important in the maintenance of smoking behaviour is necessary in order to develop an effective smoking cessation intervention. Social Cognitive Theory (SCT) offers a promising framework for smoking intervention. The related constructs of self-efficacy and outcome expectancy are fundamental to this model and have been associated with smoking initiation, maintenance, cessation and relapse. A comprehensive review of smoking intervention programs revealed that current interventions could more consistently account for these psychological factors. Additionally, though self-help materials were used extensively in the studies reviewed, research has implicated tailored self-help approaches as more effective. Only a small number of the studies reviewed used tailored materials. It was concluded that a successful smoking intervention would benefit from taking into account recent advances in psychological research and including constructs which are known to be influential for smoking cessation. Furthermore, with most smokers reporting a preference for minimal assistance and self-help materials predominating, the development of such materials needs to be sensitive to the psychological determinants which govern individual behaviour.
A comprehensive understanding of smoking behaviour is fundamental to the development of tailored smoking intervention. The constructs of self-efficacy and outcome expectancy have been thoroughly researched in the field of substance abuse and many scales to assess these constructs have been developed. A review of current scales measuring constructs related to SCT found that though current scales are generally methodologically sound, none measure self-efficacy and outcome expectancy simultaneously. It was concluded that there remains a need for a multidimensional assessment tool that measures both self-efficacy and outcome expectancy within the one questionnaire.
The Nicotine Expectancy Profile (NEP), comprising a nicotine expectancy and a selfefficacy scale, was developed using sound methodological principles and empirical techniques for item development. Using exploratory factor analysis and confirmatory structural equation modelling, seven nicotine expectancy and two self-efficacy factors were identified in total. The scale shows good concurrent validity, with a good fit for confirmatory factor analysis, acceptable internal consistency and test-retest reliability and good discriminant validity. The NEP is a novel assessment tool which adds variance to the prediction of important constructs related to smoking behaviour. Factors of both scales showed predictive relationships with regards to dependence and smoking behaviour as well as consistent content with published scales. Moderate relationships between the scales further strengthen the applicability of including both self-efficacy and nicotine expectancy within the one scale. Potential applications of the NEP are extensive and include improving the efficacy of brief motivational advice in primary care as well as improving formal cessation programs. Most importantly though, the NEP shows promise for the development of tailored self-help materials for smoking cessation.
Tailored self-help materials are more effective than standard materials and targeting individuals via personally relevant information about their particular beliefs offers a sound approach to improving intervention efficacy. A primary consideration in developing and applying a tailored intervention is the application of an individual assessment in order to establish the characteristics unique to each individual. Key items of the NEP were utilised to effectively match materials, as well as inform the development of tailored materials in the current study. These key items were selected using an empirically based method to ensure maximum sensitivity, reliability and predictive validity relative to the complete NEP. Furthermore, participatory research where the opinions and expertise of the consumer are sought to guide the development of an intervention is gaining attention in health research. Therefore, the feedback of smokers was sought via a series of focus groups to ensure that the tailored materials were both applicable and well-received. This process revealed that smokers have a strong desire to feel engaged with smoking cessation information and particularly with self-help materials. Suggestions from focus groups were incorporated in the development of a series of tailored self-help materials.
A cost effective and widely accessible method of providing smoking cessation services, particularly self-help materials, is through reactive telephone quit lines where smokers call for quit assistance. A review of recent interventions embedded within quit lines revealed substantial shortcomings in their methodology and theoretical bases. To address these deficiencies, a randomised controlled trial within the Quitline® in Queensland was conducted. Tailored materials based in SCT were trialled against the standard materials currently in use. Materials were matched to individuals using the key items identified during the process of materials development. Important constructs such as previous quit attempts and variance in selfefficacy and nicotine expectancies were expected to have an impact on smoking outcomes. Tailored materials were expected to perform better than standard materials with regards to quitting outcome and materials use.
Key outcomes of this trial included a strong positive association of materials use with quitting outcome and self-efficacy. Furthermore, significant differences in selfefficacy and nicotine expectancies were apparent across quitting outcome (quit, not quit or relapsed) and these differences have important implications for future relapse prevention and further refinement of smoking cessation intervention. Finally, previous quit attempts were found to have a significant impact on the effectiveness of self-help materials. Specifically, smokers with little quitting experience appear to benefit more from tailored information than standard information with regards to self-efficacy. Smokers with extensive quitting experience appear to benefit equally from both tailored and standard materials in increasing their self-efficacy. Future smoking interventions could be improved through more judicious distribution of tailored materials, which could not only potentially improve outcomes for less experienced quitters, but also the cost-effectiveness of applying a tailored intervention on a community-wide basis. Encouraging smokers to seek quit assistance earlier may further improve the impact of tailored self-help materials.
To conclude the current body of work, the contributions of the thesis and SCT to the understanding of smoking behaviour are discussed. In particular, the unique nature of smoking as an addiction in comparison to other drugs of abuse, the role of SCT in informing health-behaviour interventions and advances for the public research agenda with regards to the importance of addressing sub-groups of smokers are addressed. A template for future research is proposed.