Melbourne School of Psychological Sciences - Research Publications

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    Health warnings promote healthier dietary decision making: Effects of positive versus negative message framing and graphic versus text-based warnings
    Rosenblatt, DH ; Bode, S ; Dixon, H ; Murawski, C ; Summerell, P ; Ng, A ; Wakefield, M (Elsevier, 2018-08-01)
    Food product health warnings have been proposed as a potential obesity prevention strategy. This study examined the effects of text-only and text-and-graphic, negatively and positively framed health warnings on dietary choice behavior. In a 2 × 5 mixed experimental design, 96 participants completed a dietary self-control task. After providing health and taste ratings of snack foods, participants completed a baseline measure of dietary self-control, operationalized as participants' frequency of choosing healthy but not tasty items and rejecting unhealthy yet tasty items to consume at the end of the experiment. Participants were then randomly assigned to one of five health warning groups and presented with 10 health warnings of a given form: text-based, negative framing; graphic, negative framing; text, positive framing; graphic, positive framing; or a no warning control. Participants then completed a second dietary decision making session to determine whether health warnings influenced dietary self-control. Linear mixed effects modeling revealed a significant interaction between health warning group and decision stage (pre- and post-health warning presentation) on dietary self-control. Negatively framed graphic health warnings promoted greater dietary self-control than other health warnings. Negatively framed text health warnings and positively framed graphic health warnings promoted greater dietary self-control than positively framed text health warnings and control images, which did not increase dietary self-control. Overall, HWs primed healthier dietary decision making behavior, with negatively framed graphic HWs being most effective. Health warnings have potential to become an important element of obesity prevention.
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    Evaluating the influence of message framing and graphic imagery on perceptions of food product health warnings
    Rosenblatt, DH ; Dixon, H ; Wakefield, M ; Bode, S (ELSEVIER SCI LTD, 2019-10)
    Food product health warnings may be a valuable intervention strategy for helping reduce obesity rates and the negative health outcomes associated with consuming an unhealthy diet. Research into the efficacy of food product health warnings has shown promising effects on consumers’ beliefs and behaviour, but existing research has typically featured a single or limited number of simple, text-only warnings. Two studies are presented that tested the influence of text-only and text-and-graphic, positively and negatively framed health warnings on perceived efficacy, negative affect and motivation to change behaviour. Using a between-subjects design, Study 1 found that negatively framed health warnings and text-and-graphic health warnings produced more negative emotional responses than positively framed and text-only health warnings. Study 2 then featured the highest rated message topics from Study 1. Using a within-subjects design, Study 2 found that participants rated text-and-graphic health warnings as more effective than text-only warnings, and negatively framed warnings as more effective than positively framed warnings, though all warning groups scored above the scale mid-point on perceived efficacy. Negatively framed warnings produced stronger negative emotional responses, while positively framed warnings produced stronger feelings of motivation to change behaviour. Results indicate that food product health warnings were perceived as capable of effectively promoting behavioural change. While negatively framed warnings were seen as most effective, positively framed warnings may also be effective, possibly through a different persuasive pathway.
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    Adolescents' exposure to paid alcohol advertising on television and their alcohol use: exploring associations during a 13-year period
    White, V ; Azar, D ; Faulkner, A ; Coomber, K ; Durkin, S ; Livingston, M ; Chikritzhs, T ; Room, R ; Wakefield, M (WILEY, 2017-10)
    AIMS: To determine (i) whether Australian adolescents' exposure to television alcohol advertisements changed between 1999 and 2011 and (ii) examine the association between television alcohol advertising and adolescent drinking behaviours. DESIGN: Cross-sectional surveys conducted every 3 years between 1999 and 2011. Analyses examined associations between advertising exposures and reported drinking. SETTING: Five Australian major cities. PARTICIPANTS: Students aged 12-17 years participating in a triennial nationally representative school-based survey residing in the television advertising markets associated with the major cities (sample size range per survey: 12 644-16 004). MEASUREMENTS: Outcome measures were: drinking in the past month, past week and past-week risky drinking (5+ drinks on a day). The key predictor variable was past-month adolescent-directed alcohol advertising Targeted Rating Points (TRPs, a measure of television advertising exposure). Control measures included student-level characteristics, government alcohol-control advertising TRPs, road safety (drink-driving) TRPs and time of survey. FINDINGS: Average monthly adolescent alcohol TRPs increased between 1999 (mean = 2371) to 2005 (mean = 2679) (P < 0.01) then decreased between 2005 and 2011: (mean = 880) (P < 0.01). Multi-level logistic regression analyses that adjusted for survey timing, student level factors and alcohol-control advertising variables showed a significant association between past-month alcohol TRPs and past-month drinking [odds ratio (OR) = 1.11, 95% confidence interval (CI) = 1.07-1.15), past-week drinking (OR = 1.10, 95% CI = 1.06-1.14) and past-week risky drinking (OR = 1.15, 95% CI = 1.09-1.22). Past-week risky drinking was associated inversely with road safety TRPs (OR = 0.69, 95% CI = 0.49-0.98). CONCLUSIONS: While Australian adolescents' exposure to alcohol advertising on television reduced between 1999 and 2011, higher levels of past-month television alcohol advertising were associated with an increased likelihood of adolescents' drinking. The reduction in television alcohol advertising in Australia in the late 2000s may have played a part in reducing adolescents' drinking prevalence.
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    Smoking prevalence following tobacco tax increases in Australia between 2001 and 2017: an interrupted time-series analysis
    Wilkinson, AL ; Scollo, MM ; Wakefield, MA ; Spittal, MJ ; Chaloupka, FJ ; Durkin, SJ (ELSEVIER SCI LTD, 2019-12)
    BACKGROUND: Building on substantial tobacco control action over the previous decade, Australia increased the taxes on tobacco by 25% without forewarning on April 30, 2010. Australia then became one of a few countries to pre-announce a series of increases in tobacco taxes, with annual 12·5% increases starting from December, 2013. We aimed to examine the effects of both tax increases on smoking prevalence. METHODS: By use of survey data from Australians aged 14 years and older in five capital cities, we did an interrupted time-series analysis to model the monthly prevalence of smoking (overall, of factory-made cigarettes [FMC], and of roll-your-own tobacco [RYO]), in the total sample and stratified by socioeconomic status subgroups. We measured outcomes in May, 2001-April, 2010; May, 2010-November, 2013; and December, 2013-April, 2017. FINDINGS: The 25% tax increase was associated with immediate (-0·745 percentage points; 95% CI -1·378 to -0·112) and sustained reductions in prevalence (monthly trend -0·023 percentage points; -0·044 to -0·003), which were driven by reductions in the prevalence of smoking of FMC. The prevalence of smoking of RYO increased between May, 2010, and November, 2013, after the 25% tax increase. At the start of the pre-announced annual 12·5% increases, we observed an immediate reduction in smoking (-0·997 percentage points; -1·632 to -0·362), followed by decreasing overall prevalence (monthly trend -0·044 percentage points; -0·063 to -0·026) due to ongoing decreases in the prevalence of FMC smoking and a cessation of increases in the prevalence of smoking of RYO. Immediate decreases in smoking and changing trends in the prevalence of smoking of RYO were most evident among groups with a lower socioeconomic status. INTERPRETATION: Large tax increases are effective in reducing smoking prevalence, both as a single increase without forewarning and as a pre-announced series of increases. However, taxes on tobacco are best structured to apply equally to FMC and RYO products. Tobacco control policies should prohibit price marketing that otherwise erodes the full impact of such tax increases. FUNDING: Cancer Council Victoria.
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    Immediate effects on adult drinkers of exposure to alcohol harm reduction advertisements with and without drinking guideline messages: experimental study
    Wakefield, MA ; Brennan, E ; Dunstone, K ; Durkin, SJ ; Dixon, HG ; Pettigrew, S ; Slater, MD (WILEY, 2018-06)
    AIMS: To compare the immediate effects on drinkers of television advertisements focusing upon short- versus long-term harms with and without low-risk drinking guidelines. DESIGN: Between-participants on-line experiment, with random assignment to view: (a) alcohol product advertisements (ALC control); (b) advertisements unrelated to alcohol (NON-ALC control); (c) advertisements featuring short-term harms (STH) of alcohol; (d) advertisements featuring STH plus a STH guideline (STH+G); (e) advertisements featuring long-term harms (LTH); or (f) advertisements featuring LTH plus a LTH guideline (LTH+G). SETTING: Australia, 2016. PARTICIPANTS: A total of 3718 drinkers aged 18-64 years (48.5% male). MEASUREMENTS: Post-exposure likelihood that participants provided a correct estimate of drinking levels associated with short- and long-term harms; post-exposure intentions to avoid alcohol or reduce consumption. FINDINGS: After exposure to STH+G or LTH+G advertisements, participants were more likely to estimate correctly rather than overestimate drinking levels associated with harm, compared with those exposed to STH (P < 0.001) and LTH advertisements without guidelines, respectively (P = 0.019) and ALC control (STH+G, P < 0.001; LTH+G, P < 0.001) and NON-ALC control conditions (STH+G, P < 0.001; LTH+G, P = 0.011). Drinkers exposed to STH conditions were more likely to intend to reduce next-week alcohol consumption than those exposed to ALC control (both P < 0.001) and NON-ALC control conditions (STH, P = 0.001; STH+G, P < 0.001); a similar pattern was observed for intentions to avoid alcohol. Drinkers exposed to LTH conditions were also more likely than drinkers exposed to ALC or NON-ALC controls to intend to avoid and reduce alcohol in the next week. Additionally, drinkers exposed to LTH+G were more likely to intend to reduce drinking than those exposed to LTH advertisements without guidelines (P = 0.022). Response patterns for low- and high-risk drinkers by condition were similar. CONCLUSIONS: Alcohol harm television advertisements increase intentions to reduce alcohol consumption among both low- and high-risk drinkers. The addition of low-risk drinking guidelines can enhance these effects for advertisements featuring long-term harms and improve estimates of both short- and long-term harmful drinking levels.
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    Adolescents' alcohol use and strength of policy relating to youth access, trading hours and driving under the influence: findings from Australia
    White, V ; Azar, D ; Faulkner, A ; Coomber, K ; Durkin, S ; Livingston, M ; Chikritzhs, T ; Room, R ; Wakefield, M (WILEY, 2018-06)
    AIMS: To determine (i) whether the strength of Australian alcohol control policy in three domains (youth access, trading hours and drink driving) changed during the 2000s; and (ii) estimate associations between these policies and adolescent drinking after adjusting for television alcohol advertising exposures, alcohol outlet density, alcohol price changes, exposure to negative articles about alcohol in daily newspapers and adult drinking prevalence. DESIGN: Repeated cross-sectional surveys conducted triennially from 2002 to 2011. Multi-level modelling examined the association between alcohol control policies and drinking prevalence after adjusting for covariates. SETTING: Four Australian capital cities between 2002 and 2011. PARTICIPANTS: Students aged 12-17 years participating in a triennial national representative school-based survey (sample size range/survey: 9805-13 119). MEASUREMENTS: Outcome measures were: past month drinking and risky drinking (5+ drinks on a day) in the past 7 days. Policy strength in each of three domains (youth access, trading hours, drink-driving) were the key predictor variables. Covariates included: past 3-month television alcohol and alcohol-control advertising, alcohol outlet density, alcohol price change, negatively framed newspaper alcohol articles, adult drinking prevalence and student demographic characteristics. FINDINGS: During the study period, the strength of youth access policies increased by 10%, trading hours policies by 14% and drink-driving policies by 58%. Past-month and risky drinking prevalence decreased (e.g. past-month: 2002: 47.4% to 2011: 26.3%). Multivariable analyses that included all policy variables and adjusted for year, student and other covariates showed past-month drinking to be associated inversely with stronger trading hours policies [odds ratio (OR) = 0.80, 95% confidence interval (CI) = 0.69, 0.94], but not youth access (OR = 0.92 95% CI = 0.81, 1.04) or drink-driving (OR = 1.00, 95% CI = 0.93, 1.09). Risky drinking was associated inversely with stronger youth access policies (OR = 0.82, 95% CI = 0.69, 0.98), but not trading hours (OR = 0.85, 95% CI = 0.66, 1.09) or drink-driving (OR = 1.02, 95% CI = 0.90, 1.14) policies. CONCLUSIONS: Population-directed policies designed to reduce alcohol availability and promotion may reduce adolescents' alcohol use.
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    Who drinks sugar sweetened beverages and juice? An Australian population study of behaviour, awareness and attitudes.
    Miller, C ; Wakefield, M ; Braunack-Mayer, A ; Roder, D ; O'Dea, K ; Ettridge, K ; Dono, J (Springer Science and Business Media LLC, 2019)
    BACKGROUND: The rate of overweight and obesity in Australia is among the highest in the world. Yet Australia lags other countries in developing comprehensive educative or regulatory responses to address sugary drink consumption, a key modifiable risk factor that contributes substantial excess sugar to the diet. Measurement of sugary drink consumption is typically sporadic and nutrition focussed and there is limited knowledge of community perceptions and awareness of the health risks associated with excess sugary drink consumption. The aim of this study was to assess the demographic characteristics, behavioural risk factors and attitudes and knowledge associated with sugar-sweetened beverage (SSB) and 100% fruit juice consumption. METHODS: A face-to-face household survey was conducted in 2014 using a stratified random sampling strategy to represent the South Australian population aged 15 years and over. The survey contained questions on sugary drinks, with past week SSB consumption and 100% fruit juice consumption used as outcome variables. Associations were examined with demographic characteristics, behavioural risk factors, and sugary drink attitudes and knowledge. RESULTS: Of the 2732 respondents, 35% had consumed SSBs 1-6 times (moderate consumers) and 16% had consumed SSBs 7 or more times (frequent consumers) in the past week. Furthermore, 35% had consumed 100% fruit juice in the past week, with 10% consuming every day. Rates of SSB consumption were consistently higher among males, younger age groups, and groups with lower education attainment, as well as smokers and frequent consumers of fast food. Awareness of health risks and sugar content of SSBs was low, especially among frequent SSB consumers. Fruit juice consumption was higher among males, younger age groups, the physically active and among those believing that 100% fruit juice did not contain more sugar than SSBs. CONCLUSIONS: Consumption of SSBs and 100% fruit juice is common but awareness of health risks and sugar content of these drinks is low. There is a need for greater consumer understanding which could be achieved through educative approaches such as public education campaigns, on-package warning labels and improved nutrition information panels.
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    Competing with big business: a randomised experiment testing the effects of messages to promote alcohol and sugary drink control policy
    Scully, M ; Brennan, E ; Durkin, S ; Dixon, H ; Wakefield, M ; Barry, CL ; Niederdeppe, J (BMC, 2017-12-28)
    BACKGROUND: Evidence-based policies encouraging healthy behaviours are often strongly opposed by well-funded industry groups. As public support is crucial for policy change, public health advocates need to be equipped with strategies to offset the impact of anti-policy messages. In this study, we aimed to investigate the effectiveness of theory-based public health advocacy messages in generating public support for sugary drink/alcohol policies (increased taxes; sport sponsorship bans) and improving resistance to subsequent anti-policy messages typical of the sugary drink/alcohol industry. METHODS: We conducted a two-wave randomised online experiment assigning Australian adults to one of four health policies (sugary drink tax; sugary drink industry sports sponsorship ban; alcohol tax; alcohol industry sports sponsorship ban). Within each health policy, we randomised participants to one of five message conditions: (i) non-advocacy based message about the size and seriousness of the relevant health issue (control); (ii) standard pro-policy arguments alone; (iii) standard pro-policy arguments combined with an inoculation message (forewarning and directly refuting anti-policy arguments from the opposition); (iv) standard pro-policy arguments combined with a narrative message (a short, personal story about an individual's experience of the health issue); or (v) standard pro-policy arguments combined with a composite inoculation and narrative message. At time 1, we exposed participants (n = 6000) to their randomly assigned message. Around two weeks later, we re-contacted participants (n = 3285) and exposed them to an anti-policy message described as being from a representative of the sugary drink/alcohol industry. Generalised linear models tested for differences between conditions in policy support and anti-industry beliefs at both time points. RESULTS: Only the standard argument plus narrative message increased policy support relative to control at time 1. The standard argument plus narrative and standard argument plus inoculation messages were effective at increasing resistance to the persuasive impact of anti-policy messages relative to control at time 2. CONCLUSIONS: Dissemination of advocacy messages using inoculation or narrative components can help strengthen public resistance to subsequent anti-policy messages from industry groups.
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    Large-scale unassisted smoking cessation over 50 years: lessons from history for endgame planning in tobacco control
    Chapman, S ; Wakefield, MA (BMJ PUBLISHING GROUP, 2013-05)
    In the 50 years since the twentieth century's smoking epidemic began to decline from the beginning of the 1960s, hundreds of millions of smokers around the world have stopped smoking permanently. Overwhelmingly, most stopped without any formal assistance in the form of medication or professional assistance, including many millions of former heavy smokers. Nascent discussion about national and global tobacco endgame scenarios is dominated by an assumption that transitioning from cigarettes to alternative forms of potent, consumer-acceptable forms of nicotine will be essential to the success of endgames. This appears to uncritically assume (1) the hardening hypothesis: that as smoking prevalence moves toward and below 10%, the remaining smokers will be mostly deeply addicted, and will be largely unable to stop smoking unless they are able to move to other forms of 'clean' nicotine addiction such as e-cigarettes and more potent forms of nicotine replacement; and (2) an overly medicalised view of smoking cessation that sees unassisted cessation as both inefficient and inhumane. In this paper, we question these assumptions. We also note that some vanguard nations which continue to experience declining smoking prevalence have long banned smokeless tobacco and non-therapeutic forms of nicotine delivery. We argue that there are potentially risky consequences of unravelling such bans when history suggests that large-scale cessation is demonstrably possible.
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    What price quitting? The price of cigarettes at which smokers say they would seriously consider trying to quit
    Scollo, M ; Hayes, L ; Wakefield, M (BMC, 2013-07-13)
    BACKGROUND: Deciding on an appropriate level for taxes on tobacco products is a critical issue in tobacco control. The aim of the present study was to describe the critical price points for packs for smokers of each pack size, to calculate what this would equate to in terms of price per stick, and to ascertain whether price points varied by age, socio-economic status and heaviness of smoking. METHODS: In November 2011, 586 Victorian smokers of factory-made cigarettes were asked during a telephone survey about their usual brand, including the size and cost of their usual pack. They were also asked about use of illicit tobacco. Smokers estimated what price their preferred pack would need to reach before they would seriously consider quitting. RESULTS: Three-quarters of regular smokers of manufactured cigarettes could envisage their usual brand reaching a price at which they would seriously consider quitting. Analyses revealed that answers clustered around whole numbers, (AUD$15, $20, $25 and $30), with a median nominated price point of AUD$20 per pack. The median price point at which regular smokers would consider quitting was calculated to be 80 cents per stick, compared to the current median reported stick price of 60 cents.Of the smokers who nominated a price point, 60.1% indicated they would seriously consider quitting if the cost of their usual brand equated to 80 cents per stick or less; 87.5% would seriously consider quitting if sticks reached one dollar each. CONCLUSIONS: These results do suggest a potentially useful approach to setting taxes in Australia. If taxes can be set high enough to ensure that the cost of the smokers' preferred packs exceeds critical price points, then it seems likely that more people would seriously attempt to quit than if the price increased to a level even slightly below the price points. Our study suggests that a tax increase large enough to ensure that a typical pack of 25 cigarettes in Australia cost at least AUD$20 would prompt more than 60% of smokers able to nominate a price point to seriously think about quitting, with particularly strong effects among low-SES smokers.