Using a LOng peripheral intraVEnous catheter with retractable guidewire to optimize first-insertion success for patients with Difficult IntraVenous Access in the emergency department (LOVE-DIVA): a study protocol for a randomized controlled trial.

INTRODUCTION: First-insertion success rates for peripheral vascular access devices (PVADs) in patients with difficult venous access (DIVA) are low, which negatively affects staff workload, patient experience, and organizational cost. There is mixed evidence regarding the impact of a peripheral vascular access device with retractable coiled tip guidewire (GW; AccuCath™, BD) on the first-insertion success rate. The aim of this study is to investigate whether the use of long GW-PVADs, compared with standard PVADs, reduces the risk of first-time insertion failure, in patients admitted to emergency departments (EDs). METHODS AND ANALYSIS: A parallel-group, two-arm, randomized controlled trial will be carried out in two Australian EDs to compare long GW-PVADs (5.8 cm length) against standard care PVADs (short or long). Patients ≥18 years of age meeting DIVA criteria will be eligible for the trial. The sample size is 203 participants for each arm. Web-based central randomization will be used to ensure allocation concealment. Neither clinicians nor patients can be blinded to treatment allocation. Primary outcome is the first-insertion success rate. Secondary outcomes include the number of insertion attempts, time to insert PVAD, all-cause failure, dwell-time, patient-reported pain, serious adverse events, complications, subsequent vascular access devices required, patient satisfaction, staff satisfaction, and healthcare costs. Differences between the two groups will be analyzed using Cox proportional hazards regression. Cost-effectiveness analysis will also be conducted. Intention-to-treat analysis will be used. ETHICS AND DISSEMINATION: The study is approved by Metro South Ethics Committee (HREC/2022/QMS/82264) and Griffith University (2022/077). The findings will be published in a peer-reviewed journal. TRIAL REGISTRATION: ACTRN12622000299707.

Testing for selection bias and moral hazard in private health insurance: Evidence from a mixed public-private health system.

Separating selection bias from moral hazard in private health insurance (PHI) markets has been a challenging task. We estimate selection bias and moral hazard in Australia's mixed public-private health system, where PHI premiums are community-rated rather than risk-rated. Using longitudinal cohort data, with fine-grained measures for medical services predominantly funded by PHI providers, we find consistent and robust estimates of advantageous selection among hospitalized cardiovascular disease (CVD) patients. Specifically, we show that in addition to their risk-averse attributes, CVD patients who purchase PHI use fewer services that are not covered by PHI providers (e.g., general practitioners and emergency departments) and have fewer comorbidities. Finally, unlike previous studies, we show that ex-post moral hazard exists in the use of specific "in-hospital" medical services such as specialist and physician services, miscellaneous diagnostic procedures, and therapeutic treatments. From the perspective of PHI providers, the annual cost of moral hazard translates to a lower bound estimate of $707 per patient, equivalent to a 3.03% reduction in their annual profits.

Does affirmative action reduce disparities in healthcare use by Indigenous peoples? Evidence from Australia's Indigenous Practice Incentives Program.

Globally, Indigenous populations experience poorer health but use less primary healthcare than their non-Indigenous counterparts. In 2010, the Australian government introduced a targeted reform aimed at reducing these disparities. The reform reduced, or abolished prescription medicine co-payments and provided financial incentives for GPs to better manage chronic disease care for Indigenous peoples. Exploiting the framework of a natural experiment, we investigate how the reform affected these health disparities in primary and specialist healthcare utilization using longitudinal administrative data from 75,826 Australians, including 1896 Indigenous peoples, with cardiovascular disease. The differences-in-differences estimates indicate that the reform increased primary healthcare use among Indigenous peoples, including 12.9% more prescription medicines, 6.6% more GP services, and 34.0% more chronic disease services, but also reduced specialist attendances by 11.8%. Increases in primary care were larger for those who received the largest co-payment relief and lived in metropolitan regions, whereas the reduction in specialist attendances was concentrated among lower income Indigenous patients. Affirmative action can reduce inequalities in Indigenous use of primary healthcare, albeit careful design is required to ensure that benefits are equitable and do not lead to substitution away from valuable, or necessary, care.

A global perspective on the governance-health nexus.

BACKGROUND: This study raises two key arguments: First, government health expenditure (GHE) and per capita out-of-pocket expenditures on healthcare (OPEH) are sensitive to contemporary good governance practices, giving policy importance to the exogeneity of healthcare determinants, i.e., governance for health rather than health governance. Second, it is the income level of countries that reflects the volatility of the governance spillovers on the subject. METHODS: The present study constructs a composite governance index (CGI) and employs a set of panel data for 144 countries over the period from 2002 to 2020. To allow comparability and extract specific policy implications, the countries are classified as full, high-, middle-, and low-income panels. Meanwhile to delve into the short- and long-run effects of CGI on GHE and OPEH, the study employs the cross-sectionally augmented autoregressive distributed lags (CS-ARDL) model. Further, to establish a causal link between the variables, it uses the Dumitrescu-Hurlin panel causality technique. RESULTS: The results indicate that CGI is significantly cointegrated with GHE and OPEH in all recipient panels. It indicates that while CGI has significantly positive impacts on GHE and OPEH, its effects vary according to the income level of the underlying economies. The findings support the idea of governance for health and show that CGI drives the stabilization and enhancement of GHE and OPEH in the long run. Furthermore, the findings reveal that economic growth, the age dependency ratio, and tax revenue have positive effects, while the crude death rate and the child mortality rate exert negative impacts on the subject. Finally, the results highlight a unidirectional causality running from CGI to GHE and OPEH, while no feedback response is evident. CONCLUSIONS: Although an increase in GHE and OPEH is associated with the improvement of the population's healthcare, the results suggest the recognition of the importance and institutionalization of good governance to streamline this improvement through effective channelization, outreach, and social environment development for extensive health inclusion.

Is 2-Stage Septic Revision Worth the Money? A Cost-Utility Analysis of a 1-Stage Versus 2-Stage Septic Revision of Total Knee Arthroplasty.

BACKGROUND: Two-stage exchange arthroplasty remains the gold standard for the management of prosthetic joint infection (PJI) of the knee, but several studies have demonstrated that 1-stage exchange is as effective as 2-stage exchange. This study aimed to support decision-making via an economic evaluation of 1-stage compared to 2-stage exchange for total knee arthroplasty septic revision in patients who did not have compelling indication PJI (ie, Methicillin-resistant Staphylococcus aureus, multiorganism, systemic sepsis, comorbidities, culture negative, resistant organism, and immunocompromised) to undergo a 2-stage exchange. METHODS: A cost-utility analysis was performed using a Markov cohort model from the health care provider perspective using Australia data. One-stage septic knee revisions were compared with 2-stage exchange procedures for chronic PJI using a patient-lifetime horizon. Health outcomes were expressed as quality-adjusted life-years (QALY), whereas costs were presented in 2020 Australian dollars. Sensitivity analyses, population expected values of perfect information, and the perfect information for parameters (EVPPI) were assessed to estimate the opportunity costs surrounding the decision made at a willingness-to-pay threshold of $50,000 per QALY. RESULTS: The incremental cost-effectiveness ratio of 2-stage exchange compared with 1-stage exchange was $231,000 per QALY, with 98.5% of the probabilistic sensitivity simulations above the willingness-to-pay threshold. The population expected value of perfect information was $882,000, whereas the expected value of perfect information for parameters for the "cost parameters" was $207,000. CONCLUSION: The adoption of 1-stage septic knee revision is the optimal choice for patients who have a PJI and who do not have a compelling need for a 2-stage exchange arthroplasty. One-stage exchange for PJI should be advocated in patients who meet the eligibility criteria.

One-stage revision versus debridement, antibiotics, and implant retention (DAIR) for acute prosthetic knee infection: an exploratory cohort study.

INTRODUCTION: Studies have shown that debridement, antibiotics, and implant retention (DAIR) is an effective procedure for acute infection of total knee arthroplasty (TKA). This study aimed to explore DAIR and one-stage revision for homogenous cohorts with acute postoperative and acute hematogenous infection of TKA, without compelling indications to perform a staged revision. MATERIALS AND METHODS: This study was an exploratory analysis that used retrospective data from Queensland Health, Australia, for DAIR and one-stage revision of TKA between June 2010 and May 2017 (3-year average follow-up). The re-revision burden, mortality rate, and the cost of the interventions were explored. Costs were expressed in 2020 Australian dollars. RESULTS: There were 15 (DAIR) and 142 (one-stage) patients with homogenous characteristics in the sample. The re-revision burden for DAIR was 20%, while for one-stage revision it was 12.68%. Two deaths were associated with a one-stage revision and no death was associated with DAIR. The total cost since the index revision of DAIR, $162,939, was higher than for one-stage revision $130,924 (p value = 0.501), due to higher re-revision burden. CONCLUSIONS: This study would suggest the use of one-stage revision over DAIR for acute postoperative and acute hematogenous infection of TKA. It suggests that there could be other potential criteria which have not been ascertained that need to be considered for optimal DAIR selection. The study indicates the need for more research and, of note, high-quality randomized controlled trials to provide a well-defined treatment protocol with high level of evidence to guide patient selection for DAIR.

A baseline profile of the Queensland Cardiac Record Linkage Cohort (QCard) study.

BACKGROUND: Cardiovascular disease (CVD) is one of the leading causes of death in Australia. Longitudinal record linkage studies have the potency to influence clinical decision making to improve cardiac health. This paper describes the baseline characteristics of the Queensland Cardiac Record Linkage Cohort study (QCard). METHODS: International Classification of Disease, 10th Revision Australian Modification (ICD-10-AM) diagnosis codes were used to identify CVD and comorbidities. Cost and adverse health outcomes (e.g., comorbidities, hospital-acquired complications) were compared between first-time and recurrent admissions. Descriptive statistics and standard tests were used to analyse the baseline data. RESULTS: There were 132,343 patients with hospitalisations in 2010, of which 47% were recurrent admissions, and 53% were males. There were systematic differences between characteristics of recurrent and first-time hospitalisations. Patients with recurrent episodes were nine years older (70 vs. 61; p < 0.001) and experienced a twice higher risk of multiple comorbidities (3.17 vs. 1.59; p < 0.001). CVD index hospitalisations were concentrated in large metropolitan hospitals. CONCLUSIONS: Our study demonstrates that linked administrative health data provide an effective tool to investigate factors determining the progress of heart disease. Our main finding suggests that recurrent admissions were associated with higher hospital costs and a higher risk of having adverse outcomes.

Hospital frailty risk score and adverse health outcomes: evidence from longitudinal record linkage cardiac data.

BACKGROUND: Despite recent evidence on the effect of frailty on health outcomes among those with heart failure, there is a dearth of knowledge on measuring frailty using administrative health data on a wide range of cardiovascular diseases (CVD). METHODS: We conducted a retrospective record-linkage cohort study of patients with diverse CVD in Queensland, Australia. We investigated the relationship between the risk of frailty, defined using the hospital frailty risk score (HFRS), and 30-day mortality, 30-day unplanned readmission, non-home discharge, length of hospital stay (LOS) at an emergency department and inpatient units and costs of hospitalisation. Descriptive analysis, bivariate logistic regression and generalised linear models were used to estimate the association between HFRS and CVD outcomes. Smear adjustment was applied to hospital costs and the LOS for each frailty risk groups. RESULTS: The proportion of low, medium and high risk of frailty was 24.6%, 34.5% and 40.9%, respectively. The odds of frail patients dying or being readmitted within 30 days of discharge was 1.73 and 1.18, respectively. Frail patients also faced higher odds of LOS, and non-home discharge at 3.1 and 2.25, respectively. Frail patients incurred higher hospital costs (by 42.7-55.3%) and stayed in the hospital longer (by 49%). CONCLUSION: Using the HFRS on a large CVD cohort, this study confirms that frailty was associated with worse health outcomes and higher healthcare costs. Administrative data should be more accessible to research such that the HFRS can be applied to healthcare planning and patient care.

Cost of septic and aseptic revision total knee arthroplasty: a systematic review.

BACKGROUND: The increasing incidence of primary total knee arthroplasty (TKA) has led to an increase in both the incidence and the cost burden of revision TKA procedures. This study aimed to review the literature on the cost of revision TKA for septic and aseptic causes and to identify the major cost components contributing to the cost burden. METHODS: We searched MEDLINE (OvidSp), Embase, Web of Science, Cochrane Library, EconLit, and Google Scholar to identify relevant studies. Selection, data extraction and assessment of the risk of bias and cost transparency within the studies were conducted by two independent reviewers, after which the cost data were analysed narratively for 1- or 2-stage septic revision without re-revision; 2-stage septic revision with re-revision; and aseptic revision with and without re-revision, respectively. The major cost components identified in the respective studies were also reported. RESULTS: The direct medical cost from the healthcare provider perspective for high-income countries for 2-stage septic revision with re-revision ranged from US$66,629 to US$81,938, which can be about 2.5 times the cost of 1- or 2-stage septic revision without re-revision, (range: US$24,027 - US$38,109), which can be about double the cost of aseptic revision without re-revision (range: US$13,910 - US$29,213). The major cost components were the perioperative cost (33%), prosthesis cost (28%), and hospital ward stay cost (22%). CONCLUSIONS: Septic TKA revision with re-revision for periprosthetic joint infection (PJI) increases the cost burden of revision TKA by 4 times when compared to aseptic single-stage revision and by 2.5 times when compared to septic TKA revision that does not undergo re-revision. Cost reductions can be achieved by reducing the number of primary TKA that develop PJI, avoidance of re-revisions for PJI, and reduction in the length of stay after revision. TRIAL REGISTRATION: PROSPERO; CRD42020171988 .

Lifetime Costs of Hospitalised Cardiovascular Disease in Australia: An Incidence-Based Estimate.

OBJECTIVES: To estimate the incidence-based, lifetime costs of health care and productivity losses associated with cardiovascular disease (CVD) using hospital admission data from Queensland, Australia. METHODS: Retrospective analysis of data on CVD health care use sourced from Queensland Hospital Admitted Patient Data Collection (QHAPDC), Emergency Department Data Collection (EDDC), Medicare Benefits Schedule (MBS) and the Pharmaceutical Benefits Scheme (PBS). Costs were estimated from the societal perspective. Study participants included patients who were first admitted to any Queensland hospital in 2010 for a CVD-related treatment. Subsequent admissions of these patients were followed until December 2015. The present value of incidence-based lifetime costs per patient were used to estimate the total costs for Australia. All costs were presented in Australian dollars at 2019 prices. RESULTS: The estimated lifetime health care cost of CVD was AUD$65,700 per person. Productivity loss cost was higher at AUD$75,200 per person, and total indirect lifetime costs were $140,900 per person. Scaling these costs up for the Australian population, the estimated incidence-based lifetime CVD costs for Australia were $60.5 billion ($28.2 billion in direct costs and $32.3 billion in indirect costs). CONCLUSIONS: Incidence-based lifetime indirect costs of CVD were higher than the direct costs. The life-time cost structure suggests that economic benefits of health care interventions for cardiovascular diseases from a societal perspective should be at least twice as large than that from a health service perspective.

Global mapping of interventions to improve the quality of life of patients with cardiovascular diseases during 1990-2018.

BACKGROUND: Cardiovascular diseases (CVDs) have been the global health problems that cause a substantial burden for the patients and the society. Assessing the Quality of Life (QOL) of CVD patients is critical in the effectiveness evaluation of CVD treatments as well as in determining potential areas for enhancing health outcomes. Through the adoption of a combination of bibliometric approach and content analysis, publications trend and the common topics regarding interventions to improve QOL of CVD patients were searched and characterized to inform priority setting and policy development. METHODS: Bibliographic data of publications published from 1990 to 2018 on interventions to improve QOL of CVD patients were retrieved from Web of Science. Network graphs illustrating the terms co-occurrence clusters were created by VOSviewer software. Latent Dirichlet Allocation approach was adopted to classify papers into major research topics. RESULTS: A total of 6457 papers was analyzed. We found a substantial increase in the number of publications, citations, and the number of download times of papers in the last 5 years. There has been a rise in the number of papers related to intervention to increase quality of life among patients with CVD during 1990-2018. Conventional therapies (surgery and medication), and psychological, behavioral interventions were common research topics. Meanwhile, the number of papers evaluating economic effectiveness has not been as high as that of other topics. CONCLUSIONS: The research areas among the scientific studies emphasized the importance of interdisciplinary and inter-sectoral approaches in both evaluation and intervention. Future research should be a focus on economic evaluation of intervention as well as interventions to reduce mental issues among people with CVD.

Convective forcing of mercury and ozone in the Arctic boundary layer induced by leads in sea ice.

The ongoing regime shift of Arctic sea ice from perennial to seasonal ice is associated with more dynamic patterns of opening and closing sea-ice leads (large transient channels of open water in the ice), which may affect atmospheric and biogeochemical cycles in the Arctic. Mercury and ozone are rapidly removed from the atmospheric boundary layer during depletion events in the Arctic, caused by destruction of ozone along with oxidation of gaseous elemental mercury (Hg(0)) to oxidized mercury (Hg(II)) in the atmosphere and its subsequent deposition to snow and ice. Ozone depletion events can change the oxidative capacity of the air by affecting atmospheric hydroxyl radical chemistry, whereas atmospheric mercury depletion events can increase the deposition of mercury to the Arctic, some of which can enter ecosystems during snowmelt. Here we present near-surface measurements of atmospheric mercury and ozone from two Arctic field campaigns near Barrow, Alaska. We find that coastal depletion events are directly linked to sea-ice dynamics. A consolidated ice cover facilitates the depletion of Hg(0) and ozone, but these immediately recover to near-background concentrations in the upwind presence of open sea-ice leads. We attribute the rapid recoveries of Hg(0) and ozone to lead-initiated shallow convection in the stable Arctic boundary layer, which mixes Hg(0) and ozone from undepleted air masses aloft. This convective forcing provides additional Hg(0) to the surface layer at a time of active depletion chemistry, where it is subject to renewed oxidation. Future work will need to establish the degree to which large-scale changes in sea-ice dynamics across the Arctic alter ozone chemistry and mercury deposition in fragile Arctic ecosystems.

Cost-utility analysis comparing hospital-based intravenous immunoglobulin with home-based subcutaneous immunoglobulin in patients with secondary immunodeficiency.

BACKGROUND AND OBJECTIVE: Immunoglobulin replacement therapy (IRT) is often used to support patients with primary immunodeficiency disease (PID) and secondary immunodeficiency disease (SID). Home-based subcutaneous immunoglobulin (SCIg) is reported to be a cheaper and more efficient option compared to hospital-based intravenous immunoglobulin (IVIg) for PID. In contrast, there is little information on the cost-effectiveness of IRT in SID. However, patients who develop hypogammaglobulinaemia secondary to other conditions (SID) have different clinical aetiology compared to PID. This study assesses whether SCIg provides a good value-for-money treatment option in patients with secondary immunodeficiency disease (SID). METHODS: A Markov cohort simulation model with six health states was used to compare cost-effectiveness of IVIg with SCIg from a healthcare system perspective. The costs of treatment, infection and quality-adjusted life years (QALYs) for IVIg and SCIg treatment options were modelled with a time horizon of 10 years and weekly cycles. Deterministic and probabilistic sensitivity analyses were performed around key parameters. RESULTS: The cumulative cost for IVIg was A$151 511 and for SCIg A$144 296. The QALYs with IVIg were 3·07 and with SCIg 3·51. Based on the means, SCIg is the dominant strategy with better outcomes and at lower cost. The probabilistic sensitivity analysis shows that 88·3% of the 50 000 iterations fall below the nominated willingness to pay threshold of A$50 000 per QALY. Therefore, SCIg is a cost-effective treatment option. CONCLUSION: For SID patients in Queensland (Australia), the home-based SCIg treatment option provides better health outcomes and cost savings.

Economic evaluation studies in the field of HIV/AIDS: bibliometric analysis on research development and scopes (GAPRESEARCH).

BACKGROUND: The rapid decrease in international funding for HIV/AIDS has been challenging for many nations to effectively mobilize and allocate their limited resources for HIV/AIDS programs. Economic evaluations can help inform decisions and strategic planning. This study aims to examine the trends and patterns in economic evaluation studies in the field of HIV/AIDS and determine their research landscapes. METHODS: Using the Web of Science databases, we synthesized the number of papers and citations on HIV/AIDS and economic evaluation from 1990 to 2017. Collaborations between authors and countries, networks of keywords and research topics were visualized using frequency of co-occurrence and Jaccards' similarity index. A Latent Dirichlet Allocation (LDA) analysis to categorize papers into different topics/themes. RESULTS: A total of 372 economic evaluation papers were selected, including 351 cost-effectiveness analyses (CEA), 11 cost-utility analyses (CUA), 12 cost-benefit analyses (CBA). The growth of publications, their citations and usages have increased remarkably over the years. Major research topics in economic evaluation studies consisted of antiretroviral therapy (ART) initiation and treatment; drug use prevention interventions and prevention of mother-to-child transmission interventions. Moreover, lack of contextualized evidence was found in specific settings with high burden HIV epidemics, as well as emerging most-at-risk populations such as trans-genders or migrants. CONCLUSION: This study highlights the knowledge and geographical discrepancies in HIV/AIDS economic evaluation literature. Future research directions are also informed for advancing economic evaluation in HIV/AIDS research.

Modeling Research Topics for Artificial Intelligence Applications in Medicine: Latent Dirichlet Allocation Application Study.

BACKGROUND: Artificial intelligence (AI)-based technologies develop rapidly and have myriad applications in medicine and health care. However, there is a lack of comprehensive reporting on the productivity, workflow, topics, and research landscape of AI in this field. OBJECTIVE: This study aimed to evaluate the global development of scientific publications and constructed interdisciplinary research topics on the theory and practice of AI in medicine from 1977 to 2018. METHODS: We obtained bibliographic data and abstract contents of publications published between 1977 and 2018 from the Web of Science database. A total of 27,451 eligible articles were analyzed. Research topics were classified by latent Dirichlet allocation, and principal component analysis was used to identify the construct of the research landscape. RESULTS: The applications of AI have mainly impacted clinical settings (enhanced prognosis and diagnosis, robot-assisted surgery, and rehabilitation), data science and precision medicine (collecting individual data for precision medicine), and policy making (raising ethical and legal issues, especially regarding privacy and confidentiality of data). However, AI applications have not been commonly used in resource-poor settings due to the limit in infrastructure and human resources. CONCLUSIONS: The application of AI in medicine has grown rapidly and focuses on three leading platforms: clinical practices, clinical material, and policies. AI might be one of the methods to narrow down the inequality in health care and medicine between developing and developed countries. Technology transfer and support from developed countries are essential measures for the advancement of AI application in health care in developing countries.

THE DYNAMIC INTER-RELATIONSHIP BETWEEN OBESITY AND SCHOOL PERFORMANCE: NEW EMPIRICAL EVIDENCE FROM AUSTRALIA.

This paper proposes a new empirical model for examining the relationship between obesity and school performance using the simultaneous equation modelling approach. The lagged effects of both learning and health outcomes were included to capture both the dynamic and inter-relational aspects of the relationship between obesity and school performance. The empirical application of this study used comprehensive data from the first five waves of the Longitudinal Study of Australian Children (LSAC), which commenced in 2004 (wave 1) and was repeated every two years until 2018. The study sample included 10,000 children, equally divided between two cohorts (infants and children) across Australia. The empirical results show that past learning and obesity status are strongly associated with most indicators of school outcomes, including reading, writing, spelling, grammar and numeracy national tests, and scores from the internationally standardized Peabody Picture Vocabulary Test and the Matrix Reasoning Test. The main findings of this study are robust due to the choice of obesity indicator and estimation methods.

Behavioural and Emotional Problems in Children and Educational Outcomes: A Dynamic Panel Data Analysis.

This study investigates the effects of behavioural and emotional problems in children on their educational outcomes using data from the Longitudinal Survey of Australian Children (LSAC). We contribute to the extant literature using a dynamic specification to test the hypothesis of knowledge accumulation. Further, we apply the system generalised method of moments (GMM) estimator to minimise biases due to unobserved factors. We find that mental disorders in children has a negative effect on the National Assessment Program-Literacy and Numeracy (NAPLAN) test scores. Among all mental disorders, having emotional problems is found to be the most influential with one standard deviation (SD) increase in emotional problems being associated with 0.05 SD reduction in NAPLAN reading, writing and spelling; 0.04 SD reduction in matrix reasoning and grammar; and 0.03 SD reduction in NAPLAN numeracy.

Seasonal temperature is associated with Parkinson's disease prescriptions: an ecological study.

The aim of this study is to test what effect the weather may have on medications prescribed to treat Parkinson's disease. Twenty-three years of monthly time, series data was sourced from the Pharmaceutical Benefits Scheme (PBS) and the Bureau of Meteorology (BOM). Data were available for eight states and territories and their corresponding capital cities. The dependent variable was the aggregate levodopa equivalent dose (LED) for 51 Parkinson's medications identified on the PBS. Two explanatory variables of interest, temperature and solar exposure, were identified in the BOM data set. Linear and cosinor models were estimated with fixed and random effects, respectively. The prescribed LED was 4.2% greater in January and 4.5% lower in July. Statistical analysis showed that temperature was associated with the prescription of Parkinson medications. Our results suggest seasonality exists in Parkinson's disease symptoms and this may be related to temperature. Further work is needed to confirm these findings and understand the underlying mechanisms as a better understanding of the causes of any seasonal variation in Parkinson's disease may help clinicians and patients manage the disease more effectively.

A versatile method for groundwater vulnerability projections in future scenarios.

Water scarcity and associated risks are serious societal problems. A major challenge for the future will be to ensure the short-term and long-term provision of accessible and safe freshwater to meet the needs of the rapidly growing human population and changes in land cover and land use, where conservation and protection play a key role. Through a Bayesian spatial statistical method, a time-dependent approach for groundwater vulnerability assessment is developed to account for both the recent status of groundwater contamination and its evolution, as required by the European Union (Groundwater Directive, 2006/118/EC). This approach combines natural and anthropogenic factors to identify areas with a critical combination of high levels and increasing trends of nitrate concentrations, together with a quantitative evaluation of how different future scenarios would impact the quality of groundwater resources in a given area. In particular, the proposed approach can determine potential impacts on groundwater resources if policies are maintained at the status quo or if new measures are implemented for safeguarding groundwater quality, as natural factors are changing under climatic or anthropogenic stresses.

The determinants of Chinese visitors to Australia: A dynamic demand analysis.

Although China has progressively become an important inbound tourism market for Australia, its demand elasticities have been little studied to date. This study examines the determinants of Chinese visitors to Australia using a dynamic time-series estimator. Interesting findings include a high income elasticity as a source of the continuous doubledigit growth rates in Chinese arrivals that Australia has experienced over the past two decades, together with relatively high total trip price elasticities for both short run and long run. A trend of Chinese outbound to Australia is also identified. From a policy perspective, the results confirm that keeping a low cost of visiting Australia, both ground and travel costs, is a good strategy to secure greater numbers of Chinese tourists.