A comparison of subjective and objective measures of physical activity and fitness in identifying associations with cardiometabolic risk factors

Purpose
To compare the ability of alternative measures of physical activity and fitness to quantify associations with health outcomes.

Methods
Associations between a range of subjective and objective physical activity and fitness measures and cardiometabolic risk factors were examined using data from 1,631 Australians aged 26–36 years. Anthropometry, fitness, blood pressure, and fasting blood glucose, insulin, and lipids were measured at study clinics. Participants completed the International Physical Activity Questionnaire (IPAQ) and 7-day pedometer diaries; they also reported sedentary behavior (sitting, television viewing).

Results
In men and women, associations were strongest for fitness, with those in the highest (vs. lowest) fitness quarter having a 75% to 80% lower prevalence of two or more primary risk factors (waist circumference, high-density lipoprotein cholesterol, and insulin resistance). In men, a 60% to 70% reduced prevalence of two or more risk factors was observed across extreme quarters of IPAQ leisure, IPAQ vigorous, sitting duration, and pedometer measures. Similar reductions in prevalence were observed only across extreme quarters of pedometer activity and television viewing in women.

Conclusions
Associations between alternative measures and cardiometabolic risk were relatively independent, suggesting that a range of physical activity and fitness measures may be needed to most accurately quantify associations between physical activity and health.

Dancing beyond exercise : young people's experiences in dance classes

Dance classes in urban settings may have a role in health-promotion programmes seeking to increase physical activity amongst young people. However, little is so far known about the motivations, experiences or health outcomes of those participating in dance classes. This qualitative study of young people attending recreational dance classes addressed motivations, the nature of the class experience, and implications for health and well-being. Data show that young dance participants' experiences of 'the physical' are embedded in social, community/cultural or other values, and involve respect for older teachers and physical knowledge/expertise gained over the long term. Encouragement of dance-class participation may offer an important strategy for health promotion as long as the physical activity value of dance classes is not promoted in narrow, bio-mechanical terms.

Nutrition therapy in the prevention and treatment of pressure ulcers

Pressure ulcers are serious problems within hospital and aged care settings and are associated with adverse health outcomes and high treatment costs. Because of a high incidence of pressure ulcers in the health system, attention is now being directed to not just preventing, but also more effectively treating them. Nutrition plays a fundamental part in wound healing, with malnutrition, dehydration and recent weight loss identified as independent risk factors for the development of pressure ulcers. While the optimal nutrient intake to promote wound healing is unknown, increased needs for energy, protein, zinc and vitamins A, C and E have been documented. There is reasonable evidence to show that nutritional support, mostly by high-protein oral nutritional supplements, is effective in significantly reducing the incidence of pressure ulcers in at-risk patients by 25%. Intervention studies using high-protein or specialised disease-specific nutritional supplements support a trend to increased healing of established pressure ulcers. Such specialised supplements are typically based on defined amounts of arginine, vitamin C and zinc. Mechanisms by which nutritional support can aid in pressure ulcer prevention and healing are likely related to addressing macro- and/or micro-nutrient deficiencies arising from either poor oral intake or increased nutrient requirements related to the wound healing process. With much more research still to be done in this area, nutrition support appears an efficacious and costeffective adjunct to current medical and nursing approaches in the prevention and treatment of pressure ulcers.

Guideline for the non-surgical management of hip and knee osteoarthritis

Introduction: Chronic disease is a major public health burden on Australian society. An increasing proportion of the population has risk factors for, or at least one, chronic disease, leading to increasing public health costs. Health service policy and delivery must not only address acute conditions, it must also effectively respond to the wide range of health and public service requirements of people with chronic illness.^1,2 Strong primary health care policy is an important foundation for a successful national health delivery system and long term management of public health, and is linked to practical outcomes including lower mortality, decreased hospitalisation and improved health outcomes.¹ National strategic health policy has recently given increased recognition to the importance of chronic disease management, with the Australian Federal Government endorsement of a number of initiatives for the prevention (or delay in onset), early detection and evidence based management of chronic disease, including osteoarthritis.^1,3
Chronic musculoskeletal conditions, including arthritis, account for over 4% of the national disease burden in terms of disability adjusted life years. Over 6 million Australians (almost one-third of the population) are estimated to have a chronic musculoskeletal disease; chronic musculoskeletal disease represents the main cause of long term pain and physical disability. In Australia, osteoarthritis is self reported by more than 1.4 million people (7.3% of the population4) and is the tenth most commonly managed problem in general practice.5 This number is set to rise as the elderly population grows. Osteoarthritis exerts a significant burden on the individual and the community through reduction in quality of life, diminished employment capacity and an increase in health care costs. For further details, refer to the Evidence to support the National Action Plan for Osteoarthritis, Rheumatoid Arthritis and Osteoporosis: Opportunities to improve health-related quality of life and reduce the burden of disease and disability (2004).⁶
As such, federal government health policy has identified arthritis as a National Health Priority Area and adopted a number of initiatives aimed at decreasing the burden of chronic disease and disability; raising awareness of preventive disease factors; providing access to evidence based knowledge; and improving the overall management of arthritis within the community.4 In 2002, all Australian health ministers designated arthritis and musculoskeletal conditions as Australia’s seventh National Health Priority Area. In response, a National Action Plan was developed in 2004 by the National Arthritis and Musculoskeletal Conditions Advisory Group (NAMSCAG).6 The aim of this document was to provide a blueprint for national initiatives to improve the health related quality of life of people living with osteoarthritis, rheumatoid arthritis and osteoporosis; reduce the cost and prevalence of these conditions; and reduce the impact on individuals, their carers and their communities within Australia. The National Action Plan was developed to complement both the National Chronic Disease Strategy – which is broader – and the National Service Improvement Framework for Osteoarthritis, Rheumatoid Arthritis and Osteoporosis, in addition to other national and state/ territory structures.

Community engagement and working with government

Community engagement in health care can occur from policy to local community levels. It is consistent with democracy. A systems perspective can see consumers engaged to legitimise government agendas. Often community participation is via consultation instead of partnership or delegation. A community development approach to engagement can empower communities to take responsibility for their own health care. Understanding rural place facilitates alignment between health programs and community, assists incorporate community resources into health care and provides information about health needs. Rural communities, health services and other community organisations need skills in working together to develop effective partnerships that transfer some power from health systems. Rural engagement with national/state agendas is a challenge. Community engagement takes time and resources, but can be expected to lead to better health outcomes for rural residents.

Detection and treatment of hypertension in rural Australia

Background: The inequity of cardiac health outcomes between metropolitan and rural areas is well documented. As hypertension is a major cardiovascular risk factor, we need to have a better understanding of how well it is detected and managed rural areas. This study reports on the prevalence, detection and treatment of hypertension in rural Australia.

Method: Three population stratified surveys were undertaken in the Greater Green Triangle. Three thousand three hundred and twenty adults aged 25–74 years were randomly selected, stratified by gender and 10-year age groups. Anthropometric, clinical and self-administered questionnaire data relating to chronic disease risk were collected in accordance with the WHO MONICA protocol. Blood pressure (BP) was measured by trained nurses and the questionnaire collected information on the history of hypertension and medications used for treatment.

Results: Information on BP measurement, medication and awareness was available on 1506 (45%) participants. Study found that one-third of participants had hypertension. Only 54% (95% CI 47–60) of male and 71% (65–77) of female participants with hypertension were aware of their condition. While only half of the participants with hypertension were treated, only half of these treated participants had their hypertension under control. Treatment and control of hypertension was more common in women (60%, 54–67 and 55%, 47–64) compared with men (42%, 36–49 and 35%, 26–44).

Conclusion: Results of our study suggest that detection and treatment of hypertension in rural is suboptimal, particularly in men. If cardiovascular outcomes are to improve in rural Australia, people need to be encouraged to have their blood pressure measured regularly and better systems for the management of hypertension in primary care are needed.

Integration and coordination of care

The health care systems in Australia are under pressure from workforce shortages, increasing costs and an ageing population with a high prevalence of chronic disease. There is a well-established description of inequity in health outcomes among rural and remote populations. Most of the inequity appears to be due to poorer access to services than higher levels of health risk factors, such as cholesterol, blood pressure or obesity. Over the last 15 years, the science of improvement has led to quality improvement techniques, such as collaboratives, managed clinical networks and collaborative care, all of which have been tried successfully in Australia. Each of these offers ways to reduce the inequity in health outcomes attributed to rurality or remoteness.

Assessing the strain experienced by managers and professional Australian footballers using an augmented job strain model

Generic models of job stress, such as the Job Strain Model (JSM), have recently been criticised for focusing on a small number of general work characteristics while ignoring those that are occupation-specific (Sparks & Cooper, 1999). However this criticism is based on limited research that has not examined the relative influence of all three dimensions of the JSM - job demand, job control and social support - and job-specific stressors. The JSM is the most commonly used model underpinning large-scale occupational stress research (Fox, Dwyer, & Ganster, 1993) and is regarded as the most influential model in the research on the psycho-social work environment, stress and disease in recent times (Kristensen, 1995). This thesis addresses the lack of information on the relative influence of the JSM and job-specific stressors by assessing the capacity of an augmented JSM to predict the strain experienced by managers and professional Australian footballers. The augmented JSM consisted of job-specific stressors in addition to the generic components of the model. Managers and professional Australian footballers represent two very different occupational groups. While the day-today roles of a manager include planning, organising, monitoring and controlling (Carroll & Gillen, 1987), the working life of a professional Australian footballer revolves around preparing for and playing football (Shanahan, 1998). It was expected that the large differences in the work undertaken by managers and professional Australian footballers would maximise the opportunities for identifying job-specific stressors and measuring the extent that these vary from one group to the next. The large disparity between managers and professional footballers was also used to assess the cross-occupational versatility of the JSM when it had been augmented by job-specific stressors. This thesis consisted of three major studies. Study One involved a survey of Australian managers, while studies Two and Three focused on professional Australian footballers. The latter group was under-represented in the literature, and as a result of the lack of information on the stressors commonly experienced by this group, an in-depth qualitative study was undertaken in Study Two. The results from Study Two then informed the survey of professional footballers that was conducted in Study Three. Contrary to previous research examining the relative influence of generic and job-specific stressors, the results only provided moderate support for augmenting the JSM with job-specific stressors. Instead of supporting the versatility of the augmented JSM, the overall findings reinforced the broad relevance of the original JSM. Of the four health outcomes measured in Studies One and Three, there was only one - the psychological health of professional Australian footballers - where the proportion of total variance explained by job-specific stressors exceeded 13%. Despite the generally strong performance of the JSM across the two occupational groups, the importance of demand, control and support diminished when examining the less conventional occupation of professional football. The generic model was too narrow to capture the highly specific work characteristics that are important for this occupational group and, as a result, the job-specific stressors explained significantly more of the strain over and above that already provided by the generic model. These findings indicate that when investigating the stressors experienced by conventional occupational groups such as managers, the large amount resources required to identify job-specific stressors are unlikely to be cost-effective. In contrast, the influence of the more situation specific stressors is significantly greater in unconventional occupations and thus the benefits of identifying these non-generic stressors are more likely to outweigh the costs. Studies One and Three identified strong connections between job-specific stressors and important characteristics of the occupation being studied. These connections were consistent with previous research and suggest that before attempting to identify job-specific stressors, researchers need to first become familiar with the nature and context of the occupation. The final issue addressed in this thesis was the role of work and non-work support. The findings indicate that the support provided by supervisors and colleagues was a significant predictor of wellbeing for both managers and professional footballers. In contrast, the level of explained strain accounted for by non-work support was not significant. These results indicate that when developing strategies to protect and enhance employee well-being, particular attention should be given to monitoring and, where necessary, boosting the effectiveness of work-based support. The findings from this thesis have been fed back to the management and sporting communities via conference presentations and peer-reviewed journals (refer pp 220-221). All three studies have been presented at national and international conferences and, overall, were well received by participants. Similarly, the methods, results and major findings arising from Studies One and Two have been critiqued by anonymous reviewers from two international journals. These papers have been accepted for publication in 2001 and 2002 and feedback from the reviewers indicates that the findings represent a significant and unique contribution to the literature. The results of Study Three are currently under review by a sports psychology journal.

Economic evaluation of skin cancer prevention in Australia

Objectives
Australia has the highest incidence of skin cancer in the world, despite prevention campaigns being implemented since the early 1980s. This study assesses the cost-effectiveness of a skin cancer prevention program (named SunSmart) since it was introduced, together with its potential cost-effectiveness as an upgraded and ongoing national program.

Methods
The reduction in melanoma incidence attributable to SunSmart was modelled as the primary end-point. Historical expenditures on SunSmart were obtained from representative Australian states in three latitude zones. Melanoma incidence rates from these states were used to model key health outcomes. Non-melanoma skin cancer was modelled separately based on national survey results.

Results
We estimate that SunSmart has averted 28,000 disability-adjusted life-years (DALYs), equivalent to 22,000 life-years saved, in the state of Victoria since its introduction in 1988, as well as saving money from cost offset in skin cancer management (dominant). An upgraded national program for the next 20 years is estimated to avert 120,000 DALYs, with associated reductions in the use of health care resources. It remains a dominant intervention in which every dollar invested in SunSmart will return an estimated AU$2.30.

Conclusions
This study demonstrates that a sustained modest investment in skin cancer control is likely to be an excellent value for money.

Baseline comorbidities in a population-bases cohort of rheumatoid arthritis patients receiving biological therapy: data from the Australian Rheumatology Association database

Aims: To describe the baseline characteristics of an Australian population-based cohort of rheumatoid arthritis (RA) patients commencing biological therapy.

Methods: Descriptive analysis from the Australian Rheumatology Association Database (ARAD).

Results: Up to October 2006, there were 681 RA patients taking biologics enrolled in ARAD. Baseline data were available for 624 (72% female, mean (SD) age 57.0 (12.5) years). Of these, 59.5% reported at least one comorbid condition, most commonly hypertension (35.7%) and osteoporosis (30.4%); 61 (9.8%) had a history of malignancy (35 nonmelanoma skin, 5 breast, 4 bowel, 5 cervix, 3 melanoma, 3 prostate and 1 each of lip, lung, myeloma, testis, uterus, vagina). Self-reported infections within the previous 6 months were common (71.5%).

Conclusions: History of comorbidities, including recent infections, is common among Australian RA patients commencing biologics, and 10% have a history of malignancy. This may impact future evaluations of health outcomes among this population, including attribution of adverse events of biologic therapy.

Economic evaluation of a skin cancer prevention program in Australia : past achievements and future prospects

Objectives
Australia has the highest incidence of skin cancer in the world. Skin cancer prevention campaigns have been implemented in Australia for over two decades. The most notable is under the brand name, SunSmart. The aim of the current study is to assess the cost-effectiveness of SunSmart in the past and the potential cost-effectiveness of an ongoing national SunSmart program with optimal investment in the future.

Methods
An economic evaluation from a health sector perspective was conducted using the reduction in skin cancer incidence attributable to the SunSmart program modelled as the primary end-point. Historical SunSmart program expenditures were obtained from three representative states in three latitude zones, covering different levels of UVR exposure. Melanoma incidence rates from the three representative state cancer registers were used to model the health outcomes. Program effectiveness was assessed by the comparison between the well-resourced SunSmart state (Victoria) and the under-invested states (New South Wales and Queensland). Non-Melanoma Skin Cancer (NMSC) was modelled based on national survey results. 2003 was chosen as the reference year and future costs/outcomes over a 20 year time horizon were discounted at 3%.
The future level of investment in a national SunSmart was chosen to strengthen current practice by increasing current investment to a realistic and achievable level. This conservative increase in investment (expressed as ‘$ per capita’) reflected the investment level that has been achieved in Victoria over sustained periods. To model the potential cost-effectiveness of an upgraded national SunSmart program, a conservative approach was taken, whereby the same magnitude of effectiveness from 1988 to 2003 was applied to future skin cancer incidence.

Results
SunSmart in Victoria has saved 22,300 life-years, averted 27,900 disability-adjusted life-years(DALYs)(discounted) since its introduction in 1988 and achieved an incremental cost-effectiveness ratio (ICER) of $AUD 680 per life-year saved (LYS) and $AUD 540 per DALY averted. When the cost-offset from the estimated reduction in skin cancer treatment costs were taken into account, SunSmart achieved ‘dominance’. The net cost of SunSmart in the past was an estimated saving of $AUD 93 million. An upgraded national SunSmart for the next 20 years would save 91,000 life-years and avert 122,000 DALYs (discounted), involving an increased investment level from the current $AUD 0.07 per capita to the historical average of $AUD 0.28 per capita. The ICER for the upgraded SunSmart program was estimated at $AUD 940 per LYS and $AUD 700 per DALY averted. When the cost-offset is included, the program achieves dominance with a cost saving of $AUD 115 million – an estimated $AUD 2.32 return for every dollar invested between 2003 and 2022.

Conclusions
This study demonstrates that a sustained modest investment in skin cancer control is likely to be excellent value-for-money. While the available data base is certainly not prefect, key parameters would have to change dramatically for this conclusion to be challenged.

Options for change in the Australian cervical cancer screening program in context of HPV detection and vaccination

Introduction:
Cervical cancer screening has been implemented for over a decade in Australia and has significantly reduced the mortality and morbidity of the disease. The emergence of new technologies for cervical cancer, such as the Human Papillomavirus (HPV) vaccine and DNA testing has encouraged debate regarding the effective use of resources in cervical cancer prevention. The present study evaluates the cost-effectiveness, from a health sector perspective, of various screening strategies in the era of these new technologies.

Methods:
A stochastic epidemiological model using a discrete event and continuous algorithm was developed to describe the natural history of cervical cancer. By allowing one member of the cohort into the model at a time, this micro-simulation model encompasses the characteristics of heterogeneity and can track individual life histories. To evaluate the cost-effectiveness of the HPV vaccine a Markov model was built to simulate the effect on the incidence of HPV and subsequent cervical cancer. A number of proposed screening strategies were evaluated with the stochastic model for the application of HPV DNA testing, with changes in the screening interval and target population. Health outcomes were measured by Disability-Adjusted Life-Years (DALYs), adjusted for application within an evaluation setting (i.e. the mortality component of the DALY was adjusted by a disability weight when early mortality due to cervical cancer is avoided). Costs in complying with the Australian updated guidelines were assessed by pathway analysis to estimate the resources associated with cervical cancer and its pre-cancerous lesion treatment. Sensitivity analyses were performed to investigate the key parameters that influenced the cost-effectiveness results.

Results:
Current practice has already brought huge health gain by preventing more than 4,000 deaths and saving more than 86,000 life-years in a cohort of a million women. Any of the alternative screening strategies alter the total amount of health gain by a small margin compared to current practice. The results of incremental analyses of the alternative screening strategies compared to current practice suggest the adoption of the HPV DNA test as a primary screening tool every 3 years commencing at age 18, or the combined pap smear/HPV test every 3 years commencing at age 25, are more costly than current practice but with reasonable ICERs (AUD$1,810 per DALY and AUD$18,600 per DALY respectively). Delaying commencement of Pap test screening to age 25 is less costly than current practice, but involves considerable health loss. The sensitivity analysis shows, however, that the screening test accuracy has a significant impact on these conclusions. Threshold analysis indicates that a sensitivity ranging from 0.80 to 0.86 for the combined test in women younger than 30 is required to produce an acceptable incremental cost-effectiveness ratio.

Conclusions:
The adoption of HPV and combined test with an extended screening interval is more costly but affordable, resulting in reasonable ICERs. They appear good value for money for the Australian health care system, but need more information on test accuracy to make an informed decision. Potential screening policy change under current Australian HPV Vaccination Program is current work in progress. A Markov model is built to simulate the effect on the incidence of HPV and subsequent cervical cancer. Adoption of HPV DNA test as a primary screening tool in the context of HPV vaccination is under evaluation.