Australian dental policy reform and the use of dental therapists and hygienists

Oral diseases including dental caries and periodontal disease are among the most prevalent and costly diseases in Australia today. Around 5.4% of Australia’s health dollar is spent on dental services totalling around $2.6 billion, 84% of which are delivered through the private sector (AIHW 2001). The other 16% is spent providing public sector services in varied and inadequate ways. While disease rates among school children have declined significantly in the past 20 years the gains made among children are not flowing on to adult dentitions and our aging population will place increasing demands on an inadequate system into the future (AHMAC 2001). Around 50% of adults do not received regular care and this has implications for widening health inequalities as the greatest burden falls on lower income groups (AIHW DSRU 2001). The National Competition Policy agenda has initiated, Australia-wide, reviews of dental legislation applying to delivery of services by dentists, dental specialists, dental therapists and hygienists and dental technicians and prosthetists. The review of the Victorian Dentists Act 1972, was completed first in 1999, followed by the other Australian states with Queensland, the ACT and the Northern Territory still developing legislation. One of the objectives of the new Victorian Act is to ‘…promote access to dental care’. This study has grown out of the need to know more about how dental therapists and hygienists might be utilised to achieve this and the legislative frameworks that could enable such roles. This study used qualitative methods to explore dental health policy making associated with strategies that may increase access to dental care using dental therapists and hygienists. The study used a multiple case study design to critically examine the dental policy development process around the Review of the Dentists Act 1972 in Victoria; to assess legislative and regulatory dental policy reforms in other states in Australia and to conduct a comparative analysis of dental health policy as it relates to dental auxiliary practice internationally. Data collection has involved (I) semi-structured interviews with key participants and stakeholders in the policy development processes in Victoria, interstate and overseas, and (ii) analysis of documentary data sources. The study has taken a grounded theory approach whereby theoretical issues that emerged from the Victorian case study were further developed and challenged in the subsequent interstate and international case studies. A component of this study has required the development of indicators in regulatory models for dental hygienists and therapists that will increase access to dental care for the community. These indicators have been used to analyse regulation reform and the likely impacts in each setting. Despite evidence of need, evidence of the effectiveness and efficiency of dental therapists and hygienists, and the National Competition Policy agenda of increasing efficiency, the legislation reviews have mostly produces only minor changes. Results show that almost all Australian states have regulated dental therapists and hygienists in more prescriptive ways than they do dentists. The study has found that dental policy making is still dominated by the views of private practice dentists under elitist models that largely protect dentist authority, autonomy and sovereignty. The influence of dentist professional dominance has meant that governments have been reluctant to make sweeping changes. The study has demonstrated alternative models of regulation for dental therapists and hygienists, which would allow wider utilisation of their skills, more effective use of public sector funding, increased access to services and a grater focus on preventive care. In the light of theses outcomes, there is a need to continue to advocate for changes that will increase the public health focus of oral health care.

Effect of Phytophthora cinnamomi on the habitat utilization of Antechinus stuartii in a Victorian forest

Phytophthora cinnamomi (Cinnamon fungus) is a pathogenic soil fungus which infects plant communities along the south-eastern coast of Australia, and the south-western corner of Western Australia. The symptoms of this disease include chlorosis, death of branches (ie. ‘dieback’), retarded growth and the eventual death of infected plants. This leads to devastating effects upon plant communities by altering both the structural and floristic characteristics of these communities. Small mammal species are dependent on specific features of their habitat such as vegetation structure and floristics. This thesis investigated alterations to the habitat of the insectivorous marsupial mouse, Antechinus stuartii, due to the presence of P. cinnamomi. The study was undertaken in an area of an open forest in the Brisbane Ranges, Victoria. Significant changes were found in both the floristic composition and structure of the vegetation at study sites infected with P, cinnamomi, compared to uninfected sites. The habitat utilization by A. stuartii of uninfected and infected vegetation was investigated using live trapping and radio-telemetric techniques. Capture rates were higher at sites uninfected by P. cinnamomi, and both male and females selected areas free from infection. Home range areas of males were significantly larger than those of females as assessed by telemetry. Both sexes spent a high proportion of time in areas dominated by Xanthorrhoea australis (Austral grass tree). There were significant relationships between the abundance of A. stuartii and the denseness of vegetation above 1 metre in height, and in particular, the proportion of cover afforded by X. australis. There were no significant differences in the cover of Eucalyptus spp. between uninfected and infected sites, but there were significantly more nest hollows in infected areas. The abundance of invertebrates was examined using pitfall traps. There were no significant differences in the abundance of the larger invertebrate taxa at infected and uninfected sites, but higher abundances of some micro-invertebrate groups in infected areas were recorded. The most likely factors considered to be influential in the habitat selection of A. stuartii were vegetation structure, and the presence of X. australis. To assess whether these factors were important the leaves of X. australis were removed with a brushcutter, to mimic the early effects of infection with P. cinnamomi. Animals did not respond to the alteration of vegetation structure in the short term (3-4 days). Longer-term experiments are required to assess the habitat utilization of A. stuartii at different periods following habitat manipulation. The implications of the presence of P. cinnamomi on the conservation of fauna are discussed. The destructive nature of the pathogen, and the slow rate of recovery from the disease, means that P. cinnamomi can be considered a threatening process to plant communities and the fauna that reside within that habitat. Future management of this disease within natural areas must therefore be cognisant of the potential of P. cinnamomi to significantly affect faunal as well as vegetative communities.

Exposure estimation, uncertainty and variability in occupational hygiene retrospective assessment

This thesis reports on a quantitative exposure assessment and on an analysis of the attributes of the data used in the estimations, in particular distinguishing between its uncertainty and variability. A retrospective assessment of exposure to benzene was carried out for a case control study of leukaemia in the Australian petroleum industry. The study used the mean of personal task-based measurements (Base Estimates) in a deterministic algorithm and applied factors to model back to places, times etc for which no exposure measurements were available. Mean daily exposures were estimated, on an individual subject basis, by summing the task-based exposures. These mean exposures were multiplied by the years spent on each job to provide exposure estimates in ppm-years. These were summed to provide a Cumulative Estimate for each subject. Validation was completed for the model and key inputs. Exposures were low, most jobs were below TWA of 5 ppm benzene. Exposures in terminals were generally higher than at refineries. Cumulative Estimates ranged from 0.005 to 50.9 ppm-years, with 84 percent less than 10 ppm-years. Exposure probability distributions were developed for tanker drivers using Monte Carlo simulation of the exposure estimation algorithm. The outcome was a lognormal distribution of exposure for each driver. These provide the basis for alternative risk assessment metrics e.g. the frequency of short but intense exposures which provided only a minimal contribution to the long-term average exposure but may increase risk of leukaemia. The effect of different inputs to the model were examined and their significance assessed using Monte Carlo simulation. The Base Estimates were the most important determinant of exposure in the model. The sources of variability in the measured data were examined, including the effect of having censored data and the between and within-worker variability. The sources of uncertainty in the exposure estimates were analysed and consequential improvements in exposure assessment identified. Monte Carlo sampling was also used to examine the uncertainties and variability associated with the tanker drivers' exposure assessment, to derive an estimate of the range and to put confidence intervals on the daily mean exposures. The identified uncertainty was less than the variability associated with the estimates. The traditional approach to exposure estimation typically derives only point estimates of mean exposure. The approach developed here allows a range of exposure estimates to be made and provides a more flexible and improved basis for risk assessment.

Elastic behaviour in mechanical draw presses

This thesis explores the elastic behaviour of the mechanical double action press and draw die system commonly used to draw sheet metal components in the automotive industry. High process variability in production and excessive time spent in die try-out are significant problems in automotive stamping. It has previously been suggested that the elastic behaviour of the system may contribute to these problems. However, the mechanical principles that cause the press system to affect the forming process have not been documented in detail. Due to a poor understanding of these problems in industry, the elasticity of the press and tools is currently not considered during the die design. The aim of this work was to explore the physical principles of press system elasticity and determine the extent to which it contributes to problems in try-out and production. On the basis of this analysis methods were developed for controlling or accounting for problems during the design process. The application of frictional restraining force to the edges of the blank during forming depends on the distribution and magnitude of the clamping force between the binders surfaces of the draw die. This is an important control parameter for the deep drawing process. It has been demonstrated in this work that the elasticity of the press and draw die can affect clamping force in two ways. The response of the press system, to the forces produced in the press during forming, causes the magnitude of clamping force to change during the stroke. This was demonstrated using measured data from a production press. A simple linear elastic model of the press system was developed to illustrate a definite link between the measured force variation and the elasticity of the press and tools. The simple model was extended into a finite element model of the complete press system, which was used to control a forming simulation. It was demonstrated that stiffness variation within the system could influence the final strains in a drawn part. At the conclusion of this investigation a method is proposed for assessing the sensitivity of a part to clamping force variation in the press during die design. A means of reducing variation in the press through the addition of a simple linear spring element is also discussed. The second part of the work assessed the influence of tool structure on the distribution of frictional restraining forces to the blank. A forming simulation showed that tool stiffness affects the distribution of clamping pressure between the binders. This was also shown to affect the final strains in a drawn part. However, the most significant influence on restraining force was the tendency of the blank to increase in thickness between the binders during forming. Using a finite element approximation of the try-out process it was shown that the structure of the tool would also contribute to the problems currently experienced in try-out where uneven contact pressure distributions are addressed by manually adjusting the tool surfaces. Finally a generalised approach to designing draw die structures was developed. Simple analysis methods were combined with finite element based topology optimisation techniques to develop a set of basic design guidelines. The aim of the guidelines was to produce a structure with uniform stiffness response to a pressure applied at the binder surface. The work concludes with a recommendation for introducing the methods developed in this thesis into the standard production process.

Physical activity beliefs and behaviours among adults attempting weight control

Objective: To compare the frequency and duration of varying intensities of physical activity performed by adults trying to lose weight, avoid gaining weight and not actively trying to control their weight, and to compare these groups' beliefs about the physical activity they should perform.

Method: Random postal survey of 2500 Victorian adults selected from the Australian electoral roll (response rate=42%).

Measures: One-week physical activity recall (frequency and duration of walking, other moderate activity and vigorous activity), BMI (based on self-reported height and weight) and weight-control behaviour.

Results: At the time of the survey, 27% of respondents were actively trying to avoid gaining weight, 23.9% trying to lose weight and 49.1% undertaking no weight control. Respondents spent a mean time of 4.0 (±7.1) h walking, 5.5 (±7.9) h in moderate activity and 3.1(±5.9) h in vigorous activity during the week prior to the survey. Women trying to lose weight or avoid gaining weight engaged in vigorous activity more often than women not trying to control their weight. After adjusting for age, education and BMI, women trying to avoid gaining weight were 2.4 times more likely, and women trying to lose weight 2.5 times more likely, to have met current physical activity guidelines than women undertaking no weight control. On average, respondents believed they should spend 5.2 (±6.9) h walking, 6.5 (±8.2) h in moderate activity and 4.3 (±6.5) h in vigorous activity each week. Women trying to lose weight felt they should perform vigorous activity more often than other women. Weight-control behaviour was not associated with physical activity beliefs and behaviours of men.

Conclusion: Walking is a common activity among adults attempting weight control. However, many men and women do not fully recognize the value of moderate-intensity physical activity. Future efforts should be directed at promoting the role of moderate-intensity activity in weight control, particularly activity that can be performed outside of planned activity sessions.

Household composition and housing expenditures in rental-occupied and owner-occupied markets

This article examines the relationship between household compositions and housing expenditures in rental-occupied and owner-occupied markets. The author finds that renters allocate their budget proportionately between housing and nonhousing goods for an additional household member, leaving the budget share of housing expenditures unchanged. For homeowners, nevertheless, an extra member implies a reduction in housing expenditures as a share of total budget. Although age and gender compositions turn out to be significant in determining the budget share of housing expenditures for renters, they play no major role for homeowners. And although an increase in the number of working members for renters significantly reduces the share of budget spent on housing, it has no significant impact for their owner counterparts. Moreover, keeping total expenditures constant, the main income source of the head of the household does not make any difference in terms of resource allocation across housing and nonhousing goods for both renters and owners.

Personal acquaintances and salespeople in financial services: Differences between customers and friends

The existence, benefit and management of customer–salesperson relationships in the marketing of financial services are topics of increasing interest. Much of the sales and marketing literature implies that because of time spent together, salespeople and some of their customers develop close relationships that are akin to friendships. Evidence from social psychology confirms that strong relationships are founded in deep knowledge of others gained over long periods after sharing personal information. This paper reports on the results of a study of salespeople's assessments of their personal acquaintance with customers and friends in a financial services setting. The results indicate that salespeople do not classify customers as friends on all the dimensions of personal acquaintance. Furthermore, the nature of personal acquaintance differs between ‘good’ customers (those salespeople enjoy serving), and ‘bad’ (those they do not), with the exception of the personal acquaintance dimensions of interaction frequency and personal disclosure. We discuss the implications for practice and make recommendations for future research.

Patterns of physical activity for adolescent girls in Fiji and Tonga

Behavioural patterns are determined in part by sociocultural factors such as values, expected behaviours and sociopolitical organisation. This paper presents the patterns of physical activity reported by Tongan and Fijian females aged 12-18 years and possible explanations for these patterns. The paper draws on interviews conducted in a wider study of adolescents patterns of eating, physical activity and body size in Tonga, Fiji, New Zealand and Australia. The study examined sociocultural factors that could promote or protect against obesity from the perspective of adolescents in order to develop culturally-appropriate strategies for healthy lifestyles. Twenty four indigenous Fijian and 24 Tongan females aged 12-18 years were interviewed by females who were fluent in participants first languages. Researchers from Australia, Tonga and Fiji analysed the data separately and then together in order to capture cultural nuances and enhance cultural validity. This analysis revealed similarities and differences in both cultural groups. Limitations to physical activity identified by Tongan and Fijian girls included the time spent in household chores and parental restrictions.Fijian girls also identified concern about personal safety as a constraint. These findings are examined in relation to sociocultural factors that appear to limit opportunities for young females to be physically active.

Experimental evidence for the influence of food availability on incubation attendance and hatching asynchrony in the Australian reed warbler Acrocephalus australis

The amount of time a bird allocates to incubation is likely to be limited by energetic constraints. If food is abundant, energetic constraints may be reduced and the time spent incubating (incubation attendance) may increase. Moreover, the onset of incubation in relation to clutch completion may be advanced, resulting in a higher degree of hatching asynchrony. We measured the effect of experimentally increased food availability on incubation attendance and an estimate of hatching asynchrony in the Australian reed warbler Acrocephalus australis. Supplementary food was provided every other day, from a few days before the start of egg laying until just prior to hatching. Incubation attendance was measured with temperature loggers at nests receiving supplementary food and control nests. Hatching asynchrony was inferred from mass and size differences between siblings shortly after hatching. We found that 1) food supplementation resulted in an increase in incubation attendance, when comparing both nests receiving supplementary food to control nests as well as feeding to non-feeding days in nests receiving supplementary food, and 2) food supplementation resulted in a greater hatching asynchrony, without affecting clutch size, average egg volume or the likelihood of eggs hatching. This suggests that food availability acts in a proximate way to modify the extent of incubation attendance and hatching asynchrony. We discuss the adaptive significance of increased incubation attendance and a shift in the degree of hatching asynchrony in relation to food availability.

Passing time in Clifton Court : an ethnographic study of a unit for confused older people

An exploration of how the residents of a 30 bed unit for confused older people spent their time and a description of the impact upon this of any associated factors. The study demonstrates that it is possible for for elders with dementia and mental health problems to enjoy a range of activities, however, these need to be individualised to take into account the skills they have to meet the challenges with which they are presented. The informed contribution from the activities personnel and the support of nurses is vital to ensure a high quality of social interaction. Sound leadership at the clinical level is essential.

Bathymetry and frontal system interactions influence seasonal foraging movements of lactating subantarctic fur seals from Marion Island

Sixteen lactating subantarctic fur seals Arctocephalus tropicalis were satellite-tracked during the winter of 2006 (n = 6), summer of 2006/07 (n = 6) and autumn/winter (n = 4) of 2007, from Marion Island, Southern Ocean. Despite varied individual movement patterns, a favoured foraging area lay to the northeast of the island. In contrast to findings for populations at similar latitudes, seals from Marion Island did not undertake short overnight foraging trips, but trips consistently went beyond 300 km from the island. This aligns with the at-sea duration of lactating seals’ foraging trips from temperate Amsterdam Island, but differs from subantarctic Crozet and Macquarie islands. Time spent at sea, maximum distances travelled and movement variation of tracks from the island varied seasonally. Faecal analysis suggests the diet comprised primarily myctophid fish with limited seasonal variation. Well-defined areas of restricted movement coincided with significant bathymetric features to the west/northwest of the Crozet Plateau, with the Del Caño Rise clearly being important. Positive and negative sea-surface height anomalies (compared to the mean) appeared to be preferred by most seals across seasons. Higher summer sea-surface temperatures correlated with the movements of some seals. Higher chlorophyll a concentrations dictated transit and foraging areas during summer. Bathymetrically influenced oceanographic variables likely explain these preferred long-distance eastward movements. The Îles Crozet and Marion island subantarctic fur seals differ in their foraging ecology despite being neighbours. Conversely, the subantarctic fur seal populations from the distant Amsterdam and Marion islands appear to be similarly influenced by such environmental factors.

Residential density and adolescent overweight in a rapidly urbanising region of mainland China

Objective This study investigated the association of residential density with overweight among adolescents in an urban area of China.

Methods Using multistage proportional sampling methods, a population-based cross-sectional study was conducted in Nanjing between September and November 2004 (n=2375; mean age=13.9+/-1.0 years old; 46.2% boys; survey response rate=89.3%). Body mass index was calculated from self-reported body weight and height. Overweight, the main outcome variable, was defined as a BMI >/=85 percentile value for age- and gender-specific reference data according to the recommendation for Chinese adolescents. The primary explanatory variable was the residential density of the urban districts. Mixed-effects logistic regression models were used for the analysis.

Results Students in the higher and middle tertiles of residential density had a 2.17-fold (95% CI 1.41 to 3.33) and 1.89-fold (95% CI 1.22 to 2.92) higher likelihood of being overweight, respectively, compared with those in the lower tertile. The associations were slightly attenuated but still significant after adjusting for time spent in recreational physical activity and sedentary behaviour (viewing TV and sitting for academic study).

Conclusions Residential density was positively associated with overweight among urban Chinese adolescents. Our findings warrant further research examining attributes of urban environments associated with adolescents' obesity in China and potential mechanisms between them.

Sociodemographic and behavioural correlates of weight status among women with children living in socioeconomically disadvantaged neighbourhoods

Objective: To investigate sociodemographic and behavioural characteristics associated with weight status among women with children living in socioeconomically disadvantaged neighbourhoods.
Methods and procedures: A total of 1680 women aged 18–46 years, living in socioeconomically disadvantaged neighbourhoods with dependent children (aged 0–18 years), provided self-report data on height and weight and a range of sociodemographic and behavioural (for example, dietary intake, physical activity and time spent sitting) characteristics.
Results: Half of the women were classified as having a healthy weight (body mass index=18.5–25). Bivariable ordinal logistic regression analyses indicated that a healthy weight status was associated with a range of sociodemographic and behavioural characteristics. In a multivariable model, a healthy weight status among women was associated with being younger and unmarried, speaking a language other than English at home, having a medium or high level of education, and a partner with a high level of education, having a high household income, spending more time engaged in leisure-time physical activity and less time spent sitting, and having a lower consumption of soft drink.
Discussion: The present findings highlight that a considerable proportion of women with children living in disadvantaged neighbourhoods manage to maintain a healthy weight. Acknowledging the cross-sectional nature of this study, strategies aimed at helping women with children in socioeconomically disadvantaged areas to maintain their weight should focus on increasing physical activity, and reducing sitting time and soft drink consumption.

Depression, nutritional risk and eating behaviour in older caregivers

Objective
This study investigated the relationship between depression, nutritional risk and dietary intake in a population of older caregivers.

Design
Mailed questionnaire with sub group participating in a home-based interview.

Participants and setting
Seventy-six community dwelling caregivers aged 50 y or over from Victoria, Australia.

Measurements
Questionnaires provided information on weight, height, hours of care, depressive symptoms, nutritional risk and appetite. The home-based interview assessed dietary intake and shopping, cooking and meal consumption habits.

Results
The sample had a mean±SD age of 70.3±12.8 y, BMI of 27.2±4.8 kg/m2 and the time spent caring was 101.8±68.1 h/wk. Overall, 32% of caregivers had depressive symptoms, 21% were at risk of malnutrition and 21% reported their appetite was fair/bad/very bad. Caregivers with depressive symptoms (32%) compared to those with no depressive symptoms (53%) had a poorer appetite (p<0.05). Of the 20 caregivers who participated in the home interview, 25% reported they ate their meals alone.

Conclusion
A significant proportion of community dwelling older caregivers had depressive symptoms, were at risk of malnutrition and had poor appetites, although the majority were overweight or obese.

Physical activity levels of Hungarian children during school recess

Objective : The purpose of this study was to examine physical activity levels and patterns of physical activity across daily school recess periods, and the contribution of recess to daily physical activity.

Method : Ninety-eight children (61% boys) from three schools in Hungary had their physical activity quantified using uni-axial accelerometry every 5 s for three consecutive school days (Wednesday to Friday). The proportion of time spent in sedentary, light, moderate-to-vigorous, and vigorous physical activity during 5 daily school recess periods was determined using existing age-appropriate cut-points. The relative contribution of recess to daily moderate-to-vigorous physical activity was also determined. Data were collected between May and October 2008.

Results : Boys engaged in significantly more light (30.6 ± 5.2%; 27.7 ± 5.1%), moderate-to-vigorous (24.9 ± 8.9%; 17.5 ± 5.2%) and vigorous physical activity (7.6 ± 4.7%; 4.3 ± 2.9%) than girls during recess. Girls (54.8 ± 8.1%) engaged in more sedentary activity than boys (44.5 ± 10.2%). Physical activity levels were generally similar across multiple recess periods. Recess contributed more moderate-to-vigorous physical activity towards weekday physical activity for boys (13.1%) than girls (10.8%).

Conclusions : Since sedentary activity accounted for the largest proportion of recess, interventions may be needed across all recess periods to promote physical activity during the school day.