Evaluation of the cost-effectiveness of strategies claiming to reduce the risk of surgical site infections following primary total hip arthroplasty

Background Total hip arthroplasty (THA) is a commonly performed procedure and numbers are increasing with ageing populations. One of the most serious complications in THA are surgical site infections (SSIs), caused by pathogens entering the wound during the procedure. SSIs are associated with a substantial burden for health services, increased mortality and reduced functional outcomes in patients. Numerous approaches to preventing these infections exist but there is no gold standard in practice and the cost-effectiveness of alternate strategies is largely unknown. Objectives The aim of this project was to evaluate the cost-effectiveness of strategies claiming to reduce deep surgical site infections following total hip arthroplasty in Australia. The objectives were: 1. Identification of competing strategies or combinations of strategies that are clinically relevant to the control of SSI related to hip arthroplasty 2. Evidence synthesis and pooling of results to assess the volume and quality of evidence claiming to reduce the risk of SSI following total hip arthroplasty 3. Construction of an economic decision model incorporating cost and health outcomes for each of the identified strategies 4. Quantification of the effect of uncertainty in the model 5. Assessment of the value of perfect information among model parameters to inform future data collection Methods The literature relating to SSI in THA was reviewed, in particular to establish definitions of these concepts, understand mechanisms of aetiology and microbiology, risk factors, diagnosis and consequences as well as to give an overview of existing infection prevention measures. Published economic evaluations on this topic were also reviewed and limitations for Australian decision-makers identified. A Markov state-transition model was developed for the Australian context and subsequently validated by clinicians. The model was designed to capture key events related to deep SSI occurring within the first 12 months following primary THA. Relevant infection prevention measures were selected by reviewing clinical guideline recommendations combined with expert elicitation. Strategies selected for evaluation were the routine use of pre-operative antibiotic prophylaxis (AP) versus no use of antibiotic prophylaxis (No AP) or in combination with antibiotic-impregnated cement (AP & ABC) or laminar air operating rooms (AP & LOR). The best available evidence for clinical effect size and utility parameters was harvested from the medical literature using reproducible methods. Queensland hospital data were extracted to inform patients’ transitions between model health states and related costs captured in assigned treatment codes. Costs related to infection prevention were derived from reliable hospital records and expert opinion. Uncertainty of model input parameters was explored in probabilistic sensitivity analyses and scenario analyses and the value of perfect information was estimated. Results The cost-effectiveness analysis was performed from a health services perspective using a hypothetical cohort of 30,000 THA patients aged 65 years. The baseline rate of deep SSI was 0.96% within one year of a primary THA. The routine use of antibiotic prophylaxis (AP) was highly cost-effective and resulted in cost savings of over $1.6m whilst generating an extra 163 QALYs (without consideration of uncertainty). Deterministic and probabilistic analysis (considering uncertainty) identified antibiotic prophylaxis combined with antibiotic-impregnated cement (AP & ABC) to be the most cost-effective strategy. Using AP & ABC generated the highest net monetary benefit (NMB) and an incremental $3.1m NMB compared to only using antibiotic prophylaxis. There was a very low error probability that this strategy might not have the largest NMB (<5%). Not using antibiotic prophylaxis (No AP) or using both antibiotic prophylaxis combined with laminar air operating rooms (AP & LOR) resulted in worse health outcomes and higher costs. Sensitivity analyses showed that the model was sensitive to the initial cohort starting age and the additional costs of ABC but the best strategy did not change, even for extreme values. The cost-effectiveness improved for a higher proportion of cemented primary THAs and higher baseline rates of deep SSI. The value of perfect information indicated that no additional research is required to support the model conclusions. Conclusions Preventing deep SSI with antibiotic prophylaxis and antibiotic-impregnated cement has shown to improve health outcomes among hospitalised patients, save lives and enhance resource allocation. By implementing a more beneficial infection control strategy, scarce health care resources can be used more efficiently to the benefit of all members of society. The results of this project provide Australian policy makers with key information about how to efficiently manage risks of infection in THA.

An examination of keystroke dynamics for continuous user authentication

Most current computer systems authorise the user at the start of a session and do not detect whether the current user is still the initial authorised user, a substitute user, or an intruder pretending to be a valid user. Therefore, a system that continuously checks the identity of the user throughout the session is necessary without being intrusive to end-user and/or effectively doing this. Such a system is called a continuous authentication system (CAS). Researchers have applied several approaches for CAS and most of these techniques are based on biometrics. These continuous biometric authentication systems (CBAS) are supplied by user traits and characteristics. One of the main types of biometric is keystroke dynamics which has been widely tried and accepted for providing continuous user authentication. Keystroke dynamics is appealing for many reasons. First, it is less obtrusive, since users will be typing on the computer keyboard anyway. Second, it does not require extra hardware. Finally, keystroke dynamics will be available after the authentication step at the start of the computer session. Currently, there is insufficient research in the CBAS with keystroke dynamics field. To date, most of the existing schemes ignore the continuous authentication scenarios which might affect their practicality in different real world applications. Also, the contemporary CBAS with keystroke dynamics approaches use characters sequences as features that are representative of user typing behavior but their selected features criteria do not guarantee features with strong statistical significance which may cause less accurate statistical user-representation. Furthermore, their selected features do not inherently incorporate user typing behavior. Finally, the existing CBAS that are based on keystroke dynamics are typically dependent on pre-defined user-typing models for continuous authentication. This dependency restricts the systems to authenticate only known users whose typing samples are modelled. This research addresses the previous limitations associated with the existing CBAS schemes by developing a generic model to better identify and understand the characteristics and requirements of each type of CBAS and continuous authentication scenario. Also, the research proposes four statistical-based feature selection techniques that have highest statistical significance and encompasses different user typing behaviors which represent user typing patterns effectively. Finally, the research proposes the user-independent threshold approach that is able to authenticate a user accurately without needing any predefined user typing model a-priori. Also, we enhance the technique to detect the impostor or intruder who may take over during the entire computer session.

Evidence for a dual function of EphB4 as tumor promoter and suppressor regulated by the absence or presence of the ephrin-B2 ligand

Overexpression of the receptor tyrosine kinase EphB4 is common in epithelial cancers and linked to tumor progression by promoting angiogenesis, increasing survival and facilitating invasion and migration. However, other studies have reported loss of EphB4 suggesting a tumor suppressor function in some cancers. These opposing roles may be regulated by (i) the presence of the primary ligand ephrin-B2 that regulates pathways involved in tumor suppression or (ii) the absence of ephrin-B2 that allows EphB4 signaling via ligand-independent pathways that contribute to tumor promotion. To explore this theory, EphB4 was overexpressed in the prostate cancer cell line 22Rv1 and the mammary epithelial cell line MCF-10A. Overexpressed EphB4 localized to lipid-rich regions of the plasma membrane and confirmed to be ligand-responsive as demonstrated by increased phosphorylation of ERK1/2 and internalization. EphB4 overexpressing cells demonstrated enhanced anchorage-independent growth, migration and invasion, all characteristics associated with an aggressive phenotype, and therefore supporting the hypothesis that overexpressed EphB4 facilitates tumor promotion. Importantly, these effects were reversed in the presence of ephrin-B2 which led to a reduction in EphB4 protein levels, demonstrating that ligand-dependent signaling is tumor suppressive. Furthermore, extended ligand stimulation caused a significant decrease in proliferation that correlated with a rise in caspase-3/7 and -8 activities. Together, these results demonstrate that overexpression of EphB4 confers a transformed phenotype in the case of MCF-10A cells and an increased metastatic phenotype in the case of 22Rv1 cancer cells and that both phenotypes can be restrained by stimulation with ephrin-B2, in part by reducing EphB4 levels.

Subcarrier pairing and relay assignment with improved user fairness in a multi-user cooperative OFDM system

We consider a joint relay selection and subcarrier allocation problem that minimizes the total system power for a multi-user, multi-relay and single source cooperative OFDM based two hop system. The system is constrained to all users having a specific subcarrier requirement (user fairness). However no specific fairness constraints for relays are considered. To ensure the optimum power allocation, the subcarriers in two hops are paired with each other. We obtain an optimal subcarrier allocation for the single user case using a similar method to what is described in [1] and modify the algorithm for multiuser scenario. Although the optimality is not achieved in multiuser case the probability of all users being served fairly is improved significantly with a relatively low cost trade off.

Identity verification in conveyancing : the failure of current legislative and regulatory measures, and recommendations for change

"Defrauding land titles systems impacts upon us all. Those who deal in land include ordinary citizens, big business, small business, governments, not-for-profit organisation, deceased estates...Fraud here touches almost everybody." the thesis presented in this paper is that the current and disparate steps taken by jurisdictions to alleviate land fraud associated with identity-based crimes are inadequate. The centrepiece of the analysis is the consideration of two scenarios that have recently occurred. One is the typical scenario where a spouse forges the partner's signature to obtain a mortgage from a financial institution. The second is atypical. It involves a sophisticated overseas fraud duping many stakeholders involved in the conveyancing process. After outlining these scenarios, we will examine how identity verification requirements of the United Kingdom, Ontario, the Australian states, and New Zealand would have been applied to these two frauds. Our conclusion is that even though some jurisdictions may have prevented the frauds from occurring, the current requirements are inadequate. We use the lessons learnt to propose what we consider core principles for identity verification in land transactions.

Resilience by design: A participatory approach to designing an interactive digital application for promoting children's resilience

The promotion of resilience (the capacity of an individual or community to bounce back and recover from adversity) has become an important area of public health. In recent years it has expanded into the digital domain, and many online applications have been developed to promote children's resilience. In this study, it is argued that the majority of existing applications are limited because they take a didactic approach, and conceive of interaction as providing navigational choices. Because they simply provide information about resilience or replicate offline, scenario-based strategies, the understanding of resilience they provide is confined to a few, predetermined factors. In this study I propose a new, experiential approach to promoting resilience digitally. I define resilience as an emergent, situated and context-specific phenomenon. Using a Participatory Design model in combination with a salutogenic (strength-based) health methodology, this project has involved approximately 50 children as co-designers and co-researchers over two years. The children have contributed to the design of a new set of interactive resilience tools, which facilitate resilience promotion through dialogic and experiential learning. The major outcomes of this study include a new methodology for developing digital resilience tools, a new set of tools that have been developed and evaluated in collaboration with children and a set of design principles to guide future development. Beyond these initial and tangible outcomes, this study has also established that the benefits of introducing Participatory Design into a health promoting model rests primarily in the change of the role of children from "users" of technology and education to co-designers, where they assume a leadership role in both designing the tools and in directing their resilience learning.

Expression of PTRF in PC3 cells modulates cholesterol dynamics and the actin cytoskeleton impacting secretion pathways

Expression of caveolin-1 is up-regulated in prostate cancer metastasis and is associated with aggressive recurrence of the disease. Intriguingly, caveolin-1 is also secreted from prostate cancer cell lines and has been identified in secreted prostasomes. Caveolin-1 is the major structural component of the plasma membrane invaginations called caveolae. Co-expression of the coat protein Polymerase I and transcript release factor (PTRF) is required for caveolae formation. We recently found that expression of caveolin-1 in the aggressive prostate cancer cell line PC-3 is not accompanied by PTRF, leading to noncaveolar caveolin-1 lipid rafts. Moreover, ectopic expression of PTRF in PC-3 cells sequesters caveolin-1 into caveolae. Here we quantitatively analyzed the effect of PTRF expression on the PC-3 proteome using stable isotope labeling by amino acids in culture and subcellular proteomics. We show that PTRF reduced the secretion of a subset of proteins including secreted proteases, cytokines, and growth regulatory proteins, partly via a reduction in prostasome secretion. To determine the cellular mechanism accounting for the observed reduction in secreted proteins we analyzed total membrane and the detergent-resistant membrane fractions. Our data show that PTRF expression selectively impaired the recruitment of actin cytoskeletal proteins to the detergent-resistant membrane, which correlated with altered cholesterol distribution in PC-3 cells expressing PTRF. Consistent with this, modulating cellular cholesterol altered the actin cytoskeleton and protein secretion in PC-3 cells. Intriguingly, several proteins that function in ER to Golgi trafficking were reduced by PTRF expression. Taken together, these results suggest that the noncaveolar caveolin-1 found in prostate cancer cells generates a lipid raft microenvironment that accentuates secretion pathways, possibly at the step of ER sorting/exit. Importantly, these effects could be modulated by PTRF expression.

Improvising a future in the performing arts : a new strategy to help performance studies students successfully shift between academic culture, professional culture, industry and career?

If there is one thing performance studies graduates should be good at, it is improvising – play and improvisation are central to the contemporary and cultural performance practices we teach and the methods by which we teach them. Objective, offer, acceptance, advancing, reversing, character, status, manipulation, impression management, relationship management – whether we know them from Keith Johnson’s theatre theories or Erving Goffman’s theatre theories, the processes by which we play out a story, scenario or social situation to our own benefit are familiar. We understand that identity, action, interaction and its personal, aesthetic, professional or political outcomes are unpredictable, and that we need to adapt to changeable and uncertain circumstances to achieve our aims. Intriguingly, though, in a Higher Education environment that increasingly emphasises employability, skills in play, improvisation and self-performance are never cited as critical graduate attributes. Is the ability to play, improve and produce spontaneous new self-performances learned in the academy worth articulating into an ability to play, improvise and product spontaneous new self-performances after graduates leave the academy and move into the role of a performing arts professional in industry? A study of the career paths of our performance studies graduates over the past decade suggests that addressing the challenges they face in moving between academic culture, professional culture, industry and career in terms of improvisation and play principles may be very productive. In articles on performing arts careers, graduates are typically advised to find a market for their work, and develop career self-management, management and marketing skills, together with an ability to find, make and maintain relationships and opportunities for themselves. Transitioning to career is cast as a challenging process, requiring these skills, because performing arts careers do not offer the security, status and stability of other careers. Our data confirms this. In our study, though, we found that strategies commonly used to build the resilience, self-reliance and persistence graduates require – talking about portfolio careers, parallel careers, and portable, transferable or translatable skills, for example – can engender panic as easily as they engender confidence. In this paper, I consider what happens when we re-articulate some of the skills scholars and industry stakeholders argue are critical in allowing graduates to shift successfully from academy to industry in terms of skills like improvisation, play and self-performance that are already familiar, meaningful and much-practiced amongst performance studies graduates.

International tax cooperation in the Post-GFC era

Over the last five years we have observed the fallout from the global financial crisis (GFC). International cooperation and jointly adopted policies have dominated many of the solutions to the problems which have arisen. Initially, many nations in response to the GFC, implemented a two pronged short term solution by undertaking fiscal intervention and delivering rescue packages aimed at first, bailing out financial institutions and second, preventing or minimising the impact of a recession. Both programs involved large amounts of domestic spending. It was difficult in early 2007 to foresee the reduction that nations were about the face in domestic revenue collected. Five years on, not only have the first line effects of the GFC reduced the revenue raised by governments around the world, but the consequential costs associated with the rescue packages have also depleted domestic revenue bases. The response by stakeholders has been to attempt to secure domestic revenue bases through fiscally sustainable measures. Domestic sovereignty allows the levying of taxes as a nation chooses. However, rather than raise domestic taxes, revenue may also be increased by stemming the flow of income and capital to low and no-tax jurisdictions. The intervening five-year period since the GFC allows a unique insight into the response by nations and international organisations to tax evasion, tax avoidance and aggressive tax competition through the cross border flows of capital and the resulting affect that the GFC has had on international tax cooperation. By investigating the change in the international tax landscape over the last five years, which reveals the work done by stakeholders in developing fiscally responsible responses to the problems that have arisen, it may be possible to predict the trajectory of the international tax landscape over the next five years.

Working with actors in open disclosure simulations

A key strategy in facilitating learning in Open Disclosure training is the use of hypothetical, interactive scenarios called ‘simulations’. According to Clapper (2010), the ‘advantages of using simulation are numerous and include the ability to help learners make meaning of complex tasks, while also developing critical thinking and cultural skills’. Simulation, in turn, functions largely through improvisation and role-play, in which participants ‘act out’ particular roles and characters according to a given scenario, without recourse to a script. To maximise efficacy in the Open Disclosure training context, role-play requires the specialist skills of professionally trained actors. Core capacities that professional actors bring to the training process include (among others) believability, an observable and teachable skill which underpins the western traditions of actor training; and flexibility, which pertains to the actor’s ability to vary performance strategies according to the changing dynamics of the learning situation. The Patient Safety and Quality Improvement Service of Queensland Health utilises professional actors as a key component of their Open Disclosure Training Program. In engaging actors in this work, it is essential that Facilitators of Open Disclosure training have a solid understanding of the acting process: what acting is; how actors work to a brief; how they improvise; and how they sustainably manage a wide range of emotional states. In the simulation context, the highly skilled actor can optimise learning outcomes by adopting or enacting – in collaboration with the Facilitator - a pedagogical function.

Cross-cultural language learning and web design complexity

Accepting the fact that culture and language are interrelated in second language learning (SLL), the web sites should be designed to integrate with the cultural aspects. Yet many SLL web sites fail to integrate with the cultural aspects and/or focus on language acquisition only. This study identified three issues: (1) anthropologists’ cultural models mostly adopted in cross-cultural web user interface have been superficially used; (2) web designers deal with culture as a fixed one which needs to be modeled into interface design elements, so (3) there is a need for a communication framework between educators and design practitioners, which can be utilized in web design processes. This paper discusses what anthropology can contribute to language learning, mediated through web design processes and suggests a cultural user experience framework for web-based SLL by presenting an exemplary matrix. To evaluate the effectiveness of the framework, the key stakeholders (learners, teachers, and designers) participated in a case scenario-based evaluation. The result shows a high possibility that the framework can enhance the effective communication and collaboration for the cultural integration.

An interactive and adaptive building layer : strategies for allowing people to become advanced building-users

This paper reports outcomes of a pilot study to develop a conceptual framework to allow people to retrofit a building-layer to gain better control of their own built- environments. The study was initiated by the realisation that discussions surrounding the improvement of building performances tend to be about top-down technological solutions rather than to help and encourage bottom-up involvement of building-users. While users are the ultimate beneficiaries and their feedback is always appreciated, their direct involvements in managing buildings would often be regarded as obstruction or distraction. This is largely because casual interventions by uninformed building-users tend to disrupt the system. Some earlier researches showed however that direct and active participation of users could improve the building performance if appropriate training and/or systems were introduced. We also speculate this in long run would also make the built environment more sustainable. With this in mind, we looked for opportunities to retrofit our own office with an interactive layer to study how we could introduce ad-hoc systems for building-users. The aim of this paper is to describe our vision and initial attempts followed by discussion.

Enhancing opportunities to feed forward ; developing problem solving skills using web based scenarios

Universities often struggle to satisfy students’ need for feedback. This is an area where student satisfaction with courses of study can be low. Yet it is clear that one of the properties of good teaching is giving the highest quality feedback on student work. The term ‘feedback’ though is most commonly associated with summative assessment given by a teacher after work is completed. The student can often be a passive participant in the process. This paper looks at the implementation of a web based interactive scenario completed by students prior to summative assessment. It requires students to participate actively to develop and improve their legal problem solving skills. Traditional delivery of legal education focuses on print and an instructor who conveys the meaning of the written word to students. Today, mixed modes of teaching are often preferred and they can provide enhanced opportunities for feeding forward with greater emphasis on what students do. Web based activities allow for flexible delivery; they are accessible off campus, at a time that suits the student and may be completed by students at their own pace. This paper reports on an online interactive activity which provides valuable formative feedback necessary to allow for successful completion of a final problem solving assignment. It focuses on how the online activity feeds forward and contributes to the development of legal problem solving skills. Introduction to Law is a unit designed and introduced for completion by undergraduate students from faculties other than law but is focused most particularly on students enrolled in the Bachelor of Entertainment Industries degree, a joint initiative of the faculties of Creative Industries, Business and Law at the Queensland University of Technology in Australia. The final (and major) assessment for the unit is an assignment requiring students to explain the legal consequences of particular scenarios. A number of cost effective web based interactive scenarios have been developed to support the unit’s classroom activities. The tool commences with instruction on problem solving method. Students then view the stimulus which is a narrative produced in the form of a music video clip. A series of questions are posed which guide students through the process and they can compare their responses with sample answers provided. The activity clarifies the problem solving method and expectations for the summative assessment and allows students to practise the skill. The paper reports on the approach to teaching and learning taken in the unit including the design process and implementation of the activity. It includes an evaluation of the activity with respect to its effectiveness as a tool to feed forward and reflects on the implications for the teaching of law in higher education.

Australia leads with process bus

Powerlink Queensland has undertaken an aggressive program of research, development and implementation of IEC 61850-based system solutions. The intent is to move towards an IEC 61850 process bus using a two-step approach.

Executive function development and stress effects on driving performance : preliminary findings from a young adult sample.

This chapter presents a pilot study examining the interactive contributions of executive function development/impairment and psychosocial stress to young adults’ (17-30 years old) driving behaviour in a simulator city scenario.