Degree Name

Doctor of Philosophy (Clinical Psychology)


School of Psychology


Background: The risk and burden of diabetes is greatest among vulnerable populations such as people living with mental health and substance use disorders. However, there is a paucity of research examining Type 2 diabetes (T2D) risk in this population. There is a wealth of research in health risk communication which suggest the effectiveness of message framing and tailored risk feedback; however, little is known about their potential utility when used concurrently for T2D prevention in people with substance use problems.

Methods: Study 1 was a systematic review, comprised of 5 empirical studies, that examined health risk communication in people who experience substance use problems. Study 2 was an online randomised controlled trial which evaluated the effects of message framing and tailored risk feedback on T2D risk perception and behavioural intentions, and if these effects were varied by level of alcohol consumption. Three hundred and forty-seven online participants were stratified by levels of alcohol consumption and subsequently randomised to receive T2D information, risk estimates, and lifestyle recommendations that were subjected to 4 different message framing and tailoring manipulations. Study 3 involved conducting a secondary data analysis, using both archival data from cross-sectional study and data from Study 4, to examine the risk and rates of T2D among people with alcohol and/or other drug (AOD) problems. A 2x2 ANCOVA, with gender and age as covariates, was used to assess if there was a significant interaction effect between alcohol consumption and mental health disorder (MHD) on T2D risk. Study 4 assessed the effectiveness of an online T2D risk communication intervention (T2D-RC) in a sample of 459 participants with AOD problems. Participants were randomized to either the intervention or a control (COVID-19 health message) group. The T2D-RC was developed based on findings from Study 1 and 2 and it incorporated the Australian Type 2 Diabetes Risk Assessment Tool (AUSDRISK). Measures of T2D risk perception and behavioural intentions for physical activity and diet were assessed pre- and post-intervention for both Study 2 and 4.

Results: Study 1 found that message framing, specifically gain-framed messages, had a positive impact on smoking cessation. However, the limited number of studies included were characterised by heterogeneous methods and measures. Study 2 did not find any significant differences in T2D risk perceptions or behavioural intentions by study arm. However, T2D risk perception scores and accuracies, and behavioural intentions significantly increased post-intervention across all conditions. In Study 3, the secondary data analysis of pooled participants with AOD problems indicated not only a high proportion of participants diagnosed with diabetes, but also an increased risk of T2D amongst the remaining participants despite their average age being lower than the typical age of T2D onset. After accounting for gender and age, there was no significant interaction effect but there were significant main effects of alcohol consumption and MHD on T2D risk. In Study 4, participants who received the T2D-RC reported a significantly greater increase in T2D risk perception. Additionally, there was a significantly larger proportion of participants who improved their T2D risk perception accuracy compared to the control group.

Conclusion: This thesis highlights that people with AOD problems are an increased risk of developing T2D and that these individuals tend to not have an accurate perception of their risk. Health risk communication may be a viable intervention that can have positive implications on risk perception and behavioural intentions. Future research would benefit from a mixed methods approach and a greater focus on the subtle effects of message framing.

FoR codes (2008)

170106 Health, Clinical and Counselling Psychology



Unless otherwise indicated, the views expressed in this thesis are those of the author and do not necessarily represent the views of the University of Wollongong.