Cost-Benefit Model System of Chronic Diseases in Australia to Assess and Rank Prevention and Treatment Options

Chronic diseases - eg heart disease, cancer, diabetes, mental disorders - affect around 80% of older Australians, are the main causes of disability and premature death, and account for 70% of total health expenditures. Because lifestyle patterns are major risk factors, chronic disease prevention and treatment are not only of medical concern, but also of considerable social, family-level and personal interest. While this makes microsimulation approaches particularly suitable for assessing intervention costs and benefits, such approaches will need to be combined with disease-progression models if health status and treatment choices are also to be simulated. AIMS: Describe methodological and technical proposals for the development of a cost-benefit model-system. METHODS: Several chronic disease progression models are to be linked to an ‘Umbrella’ microsimulation model representing the Australian population. To project 20 years ahead, use of reweighting techniques are proposed for population projections, disease-specific predictions and for health-related projections. The model-system is to account simultaneously for Australians’ demographic, socioeconomic and health-risk-factor characteristics; progression of their health status; the number of chronic diseases (comorbidities) they accumulate over time; health-related expenditures; and changes in quality of life. Standard methods are proposed to estimate costs versus benefits of simulated policy interventions and related quality of life improvements. KEY OUTCOME: Proposal of novel methods for modelling comorbidities - a task rarely attempted, although quality of life is known to decline and health expenditures to increase well above what a linear addition of the effects of individual chronic diseases would predict.Chronic Disease, Comorbidities, Cost-Benefit Model, Australia

Prospective epidemiological study of injuries in the Australian National Soccer Competition

Sporting participation has numerous benefits to the individual and the community. Sports injury is an unfortunate consequence of participation and can have a negative physical, psychosocial and financial impact. Prevention of sporting injury can reduce the barriers to sporting participation. Injury prevention methodology considers injury surveillance to be one of the initial steps in the process of planning, developing and assessing the effectiveness of any prevention strategy implemented. Injury surveillance relies on a clear and unambiguous definition of injury and a reliable method of data collection to provide an accurate profile of injuries. Globally, there is published injury surveillance data available for professional soccer competitions in most regions of the world, with the notable exception of the Australian competition. Within Australia, injury surveillance results have been published for Rugby League, Rugby Union and Australian Rules Football. Our injury surveillance of the Australian professional soccer competition allows comparison to global injury data on soccer injuries and to other football codes within Australia. It also quantifies the significant risk of subsequent injury after an initial hip/groin injury and the player salary cost of injury in the Hyundai A-League. This new data advances the knowledge base of the sporting injury profile of professional soccer and informs the next stage of injury prevention program development

Expectancies in Double-Blind Randomised Placebo-Controlled Trials and Placebo-Induced Side Effects

The majority of research on the placebo effect has focused on beneficial effects in patients or participants told to expect an active treatment, but who are actually given a placebo. Two important and relatively understudied aspects of the placebo effect are the extent to which expectancies influence outcomes in double-blind randomised placebo-controlled trials (RCTs) and whether the placebo effect contributes to treatment side effects. The current project investigated these two issues in both clinical and experimental settings. The first study involved reanalysing a double-blind RCT of naltrexone and acamprosate for alcohol dependence based on whether participants believed they had been allocated to receive active treatment or placebo (perceived treatment). The second study extended on this by developing an experimental model for these effects using dummy (placebo only) double-blind RCTs for cognitive performance. This allowed for the manipulation of observable changes in the form of false feedback. The third study investigated whether warning participants about side effects increases their occurrence, frequency, and/or severity in three dummy trials for sleep difficulty in healthy volunteers. The final study complemented this by examining whether first time chemotherapy patients’ expectancies for nausea were associated with their post-chemotherapy nausea. The studies on perceived treatment in double-blind RCTs indicated that participants’ beliefs about their treatment allocation can influence their actual treatment outcomes via the placebo effect and that these beliefs are affected by the feedback they receive about their performance. The studies on placebo-induced side effects indicated that the placebo effect may contribute to treatment side effects but that this effect is generally likely to be small. These findings confirm that the placebo effect can influence treatment outcomes and emphasise the importance of considering patient expectancies when delivering medical treatment. They also highlight some general limitations associated with research on the placebo effect, which include, whether conveying uncertainty undermines the placebo effect and whether measuring or manipulating expectancies is the best way to evaluate the placebo effect

A Systematic Review of the Effect of Expectancy on Treatment Responses to Acupuncture

Randomised controlled trials (RCTs) of acupuncture often find equivalent responses to real and placebo acupuncture despite both appearing superior to no treatment. This raises questions regarding the mechanisms of acupuncture, especially the contribution of patient expectancies. We systematically reviewed previous research assessing the relationship between expectancy and treatment responses following acupuncture, whether real or placebo. To be included, studies needed to assess and/or manipulate expectancies about acupuncture and relate these to at least one health-relevant outcome. Nine such independent studies were identified through systematic searches of Medline, PsycInfo, PubMed, and Cochrane Clinical Trials Register. The methodology and reporting of these studies were quite heterogeneous, meaning that meta-analysis was not possible. A descriptive review revealed that five studies found statistically significant effects of expectancy on a least one outcome, with three also finding evidence suggestive of an interaction between expectancy and type of acupuncture (real or placebo). While there were some trends in significant effects in terms of study characteristics, their generality is limited by the heterogeneity of study designs. The differences in design across studies highlight some important methodological considerations for future research in this area, particularly regarding whether to assess or manipulate expectancies and how best to assess expectancies

The effect of threat on cognitive biases and pain outcomes: an eye-tracking study

Background: Theoretical accounts of attentional and interpretation biases in pain suggest that these biases are interrelated and are both influenced by perceived threat. A laboratory-based study was conducted to test whether these biases are influenced by threat, their interrelationship, and whether attention or interpretation biases predict pain outcomes. Methods: Healthy participants (n=87) received either threatening or reassuring pain information, and then completed questionnaires, interpretation and attentional bias tasks (with eye-tracking), and a pain task (the cold pressor). Results: There was an interaction effect for threat group and stimuli type on mean dwell time for face stimuli, such that there was an attentional bias towards happy faces in the low but not high threat group. Further, high threat was also associated with shorter pain tolerance, increased pain, and distress. In correlational analyses, avoidance of affective pain words was associated with increased pain. However, no relationship was found between attention and interpretation biases, and interpretation biases were not influenced by threat or associated with pain. Conclusions: These findings provide partial support for the threat interpretation model and the importance of threat and affective pain biases, yet no relationship between cognitive processing biases was found, which may only occur in clinical pain samples

The healthiness of food and beverage advertising on Sydney train stations: regulation and policy implications

The results of this study highlight the inadequacy of Australia’s voluntary self-regulatory system in protecting train commuters from exposure to unhealthy food and beverage advertising. Regulatory action by state government, such as placing a cap on the number of discretionary food advertisements per station, is required to address this issue

Attentional bias modification and pain: The role of sensory and affective stimuli

There is growing evidence to support attentional bias modification (ABM) techniques such as the modified dot-probe task within the pain literature. Such techniques can help to inform theoretical models of pain by identifying the causal role of attentional bias constructs. The aim of this research was to explore the effects of dot-probe ABM that trains individuals towards (+) or away from (-) sensory (S) and affective (A) pain words, on attentional biases, interpretation biases, and pain outcomes. Healthy undergraduate students (N= 106) completed questionnaires, an attentional bias dot-probe task, and an interpretation bias task before and after ABM, one of four ABM versions that differed in training direction (S+A+, S-A+, S+A-, S-A-), and pain outcomes using the cold pressor task. Those trained towards affective pain words were found to have a greater pain threshold but also greater distress at tolerance. However, mechanisms of change could not be established, as ABM did not affect attentional or interpretation bias, even though changes in attentional bias were associated with pain outcomes. These findings provide partial support for the threat interpretation model and highlight the utility of affective pain ABM, although further investigation of causal mechanisms is warranted

Triple therapy combinations for the treatment of type 2 diabetes - A network meta-analysis

Aim: To estimate and compare the results from all randomised trials of triple combinations of anti-diabetes therapies that reported the reduction of glycated haemoglobin (HbA1c) and associated effects on body weight and hypoglycaemia. Methods: PubMed and the Cochrane Library were searched for trials with at least one study arm on triple therapy and which reported the differences in mean change in HbA1c between two study arms. These were included in a network meta-analysis. Results: Altogether, 15,182 participants from 40 trials with treatment duration of 6-12 months were included. Compared with none/placebo added to dual therapy, the addition of a drug therapy from six of eight drug classes to existing dual therapy resulted in significant additional mean reductions in HbA1c from -0.56% (-6.2 mmol/mol; dipeptidyl peptidase 4 inhibitors) to -0.94% (-10.3 mmol/mol; thiazolidinediones). Of the six drug classes, three were associated with less favourable weight change and two were associated with more favourable weight change when compared with none/placebo added to dual therapy. Furthermore, five drug classes were associated with greater odds of hypoglycaemia. Similar results were observed in analyses of studies with a 6 month treatment duration and after excluding study arms that contained insulin. Conclusions: Overall triple therapy combinations were similar in improving diabetes control although there were some differences in adverse effects. By balancing the risks and benefits of each therapy, the estimates of pairwise comparisons of triple therapies for HbA1c, body weight and hypoglycaemia provided in this study may further inform evidence based practice

Placebo caffeine reduces withdrawal in abstinent coffee drinkers

Background: Expectancies have been shown to play a role in the withdrawal syndrome of many drugs of addiction. However no studies have examined the effects of expectancies across a broad range of caffeine withdrawal symptoms, including craving. Aims: The purpose of the current study was to use caffeine as a model to test the effect of expectancy on withdrawal symptoms, specifically whether the belief that one has ingested caffeine is sufficient to reduce caffeine withdrawal symptoms and cravings in abstinent caffeine drinkers. Methods 24-h abstinent regular coffee drinkers completed the Caffeine Withdrawal Symptom Questionnaire (CWSQ) before and after receiving decaffeinated coffee. Half the participants were led to believe the coffee was regular caffeinated coffee (Told group) and half were told that it was decaffeinated (Low Expectancy group). Results: Participants in the High Expectancy group reported a significantly greater reduction in craving, fatigue, lack of alertness and flu-like feelings factors of the CWSQ than those in the Low Expectancy. Conclusions: These results indicate that the belief that one has consumed caffeine can affect caffeine withdrawal symptoms, especially craving, even when no caffeine has been consumed

Nocebo Hyperalgesia, Partial Reinforcement, and Extinction

Many studies have found evidence of conditioning-induced nocebo hyperalgesia. However, these studies have exclusively involved continuous reinforcement schedules. Thus, it is currently unknown whether nocebo hyperalgesia can result following partial reinforcement. We tested this using electrodermal pain stimulation in healthy volunteers. Undergraduates (n=135) received nocebo treatment under the guise of a hyperalgesic. Participants were randomly allocated to continuous reinforcement (CRF), partial reinforcement (PRF), or control (no conditioning). Conditioning involved surreptitiously increasing pain stimulation on nocebo trials relative to control trials. During training, the CRF group always had the nocebo paired with the surreptitious pain increase, whereas the PRF group only experienced the increase on 62.5% of nocebo trials. In the test phase, pain stimulation was equivalent across nocebo and control trials. Partial reinforcement was sufficient to induce nocebo hyperalgesia, however, this was weaker than continuous reinforcement. Interestingly, nocebo hyperalgesia failed to extinguish irrespective of the training schedule. Additional assessment of expectancies indicated strong concordance between these and nocebo hyperalgesia. Overall, these findings suggest that once established, nocebo hyperalgesia may be difficult to disrupt. As such, partial reinforcement may be one method of reducing the intensity of nocebo hyperalgesia in the clinic, which may be particularly important given its persistence. Perspectives: This study provides novel evidence that partial reinforcement results in weaker nocebo hyperalgesia than continuous reinforcement and that nocebo hyperalgesia fails to extinguish, irrespective of the training schedule. As a result, partial reinforcement may serve as a method for reducing the intensity of nocebo hyperalgesia in the clinic