Bayesian versus frequentist statistical inference for investi gating a one-off cancer cluster reported to a health department

Background The problem of silent multiple comparisons is one of the most difficult statistical problems faced by scientists. It is a particular problem for investigating a one-off cancer cluster reported to a health department because any one of hundreds, or possibly thousands, of neighbourhoods, schools, or workplaces could have reported a cluster, which could have been for any one of several types of cancer or any one of several time periods. Methods This paper contrasts the frequentist approach with a Bayesian approach for dealing with silent multiple comparisons in the context of a one-off cluster reported to a health department. Two published cluster investigations were re-analysed using the Dunn-Sidak method to adjust frequentist p-values and confidence intervals for silent multiple comparisons. Bayesian methods were based on the Gamma distribution. Results Bayesian analysis with non-informative priors produced results similar to the frequentist analysis, and suggested that both clusters represented a statistical excess. In the frequentist framework, the statistical significance of both clusters was extremely sensitive to the number of silent multiple comparisons, which can only ever be a subjective "guesstimate". The Bayesian approach is also subjective: whether there is an apparent statistical excess depends on the specified prior. Conclusion In cluster investigations, the frequentist approach is just as subjective as the Bayesian approach, but the Bayesian approach is less ambitious in that it treats the analysis as a synthesis of data and personal judgements (possibly poor ones), rather than objective reality. Bayesian analysis is (arguably) a useful tool to support complicated decision-making, because it makes the uncertainty associated with silent multiple comparisons explicit.

Commercialisation of regenerative human tissue : Regulation and reform in Australia and England, Wales and Northern Ireland

The commercialisation of therapeutic products containing regenerative human tissue is regulated by the common law, statute and ethical guidelines in Australia and England, Wales and Northern Ireland. This article examines the regulatory regimes in these jurisdictions and considers whether reform is required to both support scientific research and ensure conformity with modern social views on medical research and the use of human tissue. The authors consider the crucial role of informed consent in striking the balance between the interests of researchers and the interests of the public.

Dancing between diversity and consistency : refining assessment in postgraduate degrees in dance

This publication is the culmination of a 2 year Australian Learning and Teaching Council's Project Priority Programs Research Grant which investigates key issues and challenges in developing flexible guidelines lines for best practice in Australian Doctoral and Masters by Research Examination, encompassing the two modes of investigation, written and multi-modal (practice-led/based) theses, their distinctiveness and their potential interplay. The aims of the project were to address issues of assessment legitimacy raised by the entry of practice-orientated dance studies into Australian higher degrees; examine literal embodiment and presence, as opposed to cultural studies about states of embodiment; foreground the validity of questions around subjectivity and corporeal intelligence/s and the reliability of artistic/aesthetic communications, and finally to celebrate ‘performance mastery’(Melrose 2003) as a rigorous and legitimate mode of higher research. The project began with questions which centred around: the functions of higher degree dance research; concepts of 'master-ness’ and ‘doctorateness’; the kinds of languages, structures and processes which may guide candidates, supervisors, examiners and research personnel; the purpose of evaluation/examination; addressing positive and negative attributes of examination. Finally the study examined ways in which academic/professional, writing/dancing, tradition/creation and diversity/consistency relationships might be fostered to embrace change. Over two years, the authors undertook a qualitative national study encompassing a triangulation of semi-structured face to face interviews and industry forums to gather views from the profession, together with an analysis of existing guidelines, and recent literature in the field. The most significant primary data emerged from 74 qualitative interviews with supervisors, examiners, research deans and administrators, and candidates in dance and more broadly across the creative arts. Qualitative data gathered from the two primary sources, was coded and analysed using the NVivo software program. Further perspectives were drawn from international consultant and dance researcher Susan Melrose, as well as publications in the field, and initial feedback from a draft document circulated at the World Dance Alliance Global Summit in July 2008 in Brisbane. Refinement of data occurred in a continual sifting process until the final publication was produced. This process resulted in a set of guidelines in the form of a complex dynamic system for both product and process oriented outcomes of multi-modal theses, along with short position papers on issues which arose from the research such as contested definitions, embodiment and ephemerality, ‘liveness’ in performance research higher degrees, dissolving theory/practice binaries, the relationship between academe and industry, documenting practices and a re-consideration of the viva voce.

Strains as Mediators between Job Characteristics and Work-Related Outcomes in Police Officers

The relationship between job characteristics (e.g., job demands, social support) and work-related outcomes (e.g., turnover intentions, job performance) is assumed to be mediated by strains (e.g., work-related well-being, psychological strain). However, evidence suggests this association will be stronger for work-related strains than broader measures of overall psychological well-being. The primary aim of this study was to identify whether work and non-work related strains differ significantly in their ability to mediate between job characteristics and work-related outcomes. Perceptions of job characteristics, strain, turnover intentions and job performance were collected via a self-report survey from 2,588 Australian police officers. All job characteristics (job demands, job control, supervisor support and colleague support) were significant predictors of both job performance and turnover intentions, with the exception of job demands, which was not a significant predictor of turnover intentions. Both work and non-work related strains were significant predictors of turnover intentions and job performance. Strains were collectively significant in mediating between job characteristics and work-related outcomes, except in the case of job demands and job performance. The indirect effects of job characteristics on work-related outcomes were primarily through officers’ work-related enthusiasm. The relative importance of work-related enthusiasm in mediating between job characteristics and work-related outcomes offers some support for previous research suggesting stronger associations between work-related constructs. Future research should examine whether there are substantial differences in the explanatory power of work-related enthusiasm and a popular related construct, work engagement.

Quality issues for the National Bowel Cancer Screening Program (NBCSP)

Purpose: This two-part research project was undertaken as part of the planning process by Queensland Health (QH), Cancer Screening Services Unit (CSSU), Queensland Bowel Cancer Screening Program (QBCSP), in partnership with the National Bowel Cancer Screening Program (NBCSP), to prepare for the implementation of the NBCSP in public sector colonoscopy services in QLD in late 2006. There was no prior information available on the quality of colonoscopy services in Queensland (QLD) and no prior studies that assessed the quality of colonoscopy training in Australia. Furthermore, the NBCSP was introduced without extra funding for colonoscopy service improvement or provision for increases in colonoscopic capacity resulting from the introduction of the NBCSP. The main purpose of the research was to record baseline data on colonoscopy referral and practice in QLD and current training in colonoscopy Australia-wide. It was undertaken from a quality improvement perspective. Implementation of the NBCSP requires that all aspects of the screening pathway, in particular colonoscopy services for the assessment of positive Faecal Occult Blood Tests (FOBTs), will be effective, efficient, equitable and evidence-based. This study examined two important aspects of the continuous quality improvement framework for the NBCSP as they relate to colonoscopy services: (1) evidence-based practice, and (2) quality of colonoscopy training. The Principal Investigator was employed as Senior Project Officer (Training) in the QBCSP during the conduct of this research project. Recommendations from this research have been used to inform the development and implementation of quality improvement initiatives for provision of colonoscopy in the NBCSP, its QLD counterpart the QBCSP and colonoscopy services in QLD, in general. Methods – Part 1 Chart audit of evidence-based practice: The research was undertaken in two parts from 2005-2007. The first part of this research comprised a retrospective chart audit of 1484 colonoscopy records (some 13% of all colonoscopies conducted in public sector facilities in the year 2005) in three QLD colonoscopy services. Whilst some 70% of colonoscopies are currently conducted in the private sector, only public sector colonoscopy facilities provided colonoscopies under the NBCSP. The aim of this study was to compare colonoscopy referral and practice with explicit criteria derived from the National Health & Medical Research Council (NHMRC) (1999) Clinical Practice Guidelines for the Prevention, Early Detection and Management of Colorectal Cancer, and describe the nature of variance with the guidelines. Symptomatic presentations were the most common indication for colonoscopy (60.9%). These comprised per rectal bleeding (31.0%), change of bowel habit (22.1%), abdominal pain (19.6%), iron deficiency anaemia (16.2%), inflammatory bowel disease (8.9%) and other symptoms (11.4%). Surveillance and follow-up colonoscopies accounted for approximately one-third of the remaining colonoscopy workload across sites. Gastroenterologists (GEs) performed relatively more colonoscopies per annum (59.9%) compared to general surgeons (GS) (24.1%), colorectal surgeons (CRS) (9.4%) and general physicians (GPs) (6.5%). Guideline compliance varied with the designation of the colonoscopist. Compliance was lower for CRS (62.9%) compared to GPs (76.0%), GEs (75.0%), GSs (70.9%, p<0.05). Compliance with guideline recommendations for colonoscopic surveillance for family history of colorectal cancer (23.9%), polyps (37.0%) and a past history of bowel cancer (42.7%), was by comparison significantly lower than for symptomatic presentations (94.4%), (p<0.001). Variation with guideline recommendations occurred more frequently for polyp surveillance (earlier than guidelines recommend, 47.9%) and follow-up for past history of bowel cancer (later than recommended, 61.7%, p<0.001). Bowel cancer cases detected at colonoscopy comprised 3.6% of all audited colonoscopies. Incomplete colonoscopies occurred in 4.3% of audited colonoscopies and were more common among women (76.6%). For all colonoscopies audited, the rate of incomplete colonoscopies for GEs was 1.6% (CI 0.9-2.6), GPs 2.0% (CI 0.6-7.2), GS 7.0% (CI 4.8-10.1) and CRS 16.4% (CI 11.2-23.5). 18.6% (n=55) of patients with a documented family history of bowel cancer had colonoscopy performed against guidelines recommendations (for general (category 1) population risk, for reasons of patient request or family history of polyps, rather than for high risk status for colorectal cancer). In general, family history was inadequately documented and subsequently applied to colonoscopy referral and practice. Methods - Part 2 Surveys of quality of colonoscopy training: The second part of the research consisted of Australia-wide anonymous, self-completed surveys of colonoscopy trainers and their trainees to ascertain their opinions on the current apprenticeship model of colonoscopy in Australia and to identify any training needs. Overall, 127 surveys were received from colonoscopy trainers (estimated response rate 30.2%). Approximately 50% of trainers agreed and 27% disagreed that current numbers of training places were adequate to maintain a skilled colonoscopy workforce in preparation for the NBCSP. Approximately 70% of trainers also supported UK-style colonoscopy training within dedicated accredited training centres using a variety of training approaches including simulation. A collaborative approach with the private sector was seen as beneficial by 65% of trainers. Non-gastroenterologists (non-GEs) were more likely than GEs to be of the opinion that simulators are beneficial for colonoscopy training (χ2-test = 5.55, P = 0.026). Approximately 60% of trainers considered that the current requirements for recognition of training in colonoscopy could be insufficient for trainees to gain competence and 80% of those indicated that ≥ 200 colonoscopies were needed. GEs (73.4%) were more likely than non-GEs (36.2%) to be of the opinion that the Conjoint Committee standard is insufficient to gain competence in colonoscopy (χ2-test = 16.97, P = 0.0001). The majority of trainers did not support training either nurses (73%) or GPs in colonoscopy (71%). Only 81 (estimated response rate 17.9%) surveys were received from GS trainees (72.1%), GE trainees (26.3%) and GP trainees (1.2%). The majority were males (75.9%), with a median age 32 years and who had trained in New South Wales (41.0%) or Victoria (30%). Overall, two-thirds (60.8%) of trainees indicated that they deemed the Conjoint Committee standard sufficient to gain competency in colonoscopy. Between specialties, 75.4% of GS trainees indicated that the Conjoint Committee standard for recognition of colonoscopy was sufficient to gain competence in colonoscopy compared to only 38.5% of GE trainees. Measures of competency assessed and recorded by trainees in logbooks centred mainly on caecal intubation (94.7-100%), complications (78.9-100%) and withdrawal time (51-76.2%). Trainees described limited access to colonoscopy training lists due to the time inefficiency of the apprenticeship model and perceived monopolisation of these by GEs and their trainees. Improvements to the current training model suggested by trainees included: more use of simulation, training tools, a United Kingdom (UK)-style training course, concentration on quality indicators, increased access to training lists, accreditation of trainers and interdisciplinary colonoscopy training. Implications for the NBCSP/QBCSP: The introduction of the NBCSP/QBCSP necessitates higher quality colonoscopy services if it is to achieve its ultimate goal of decreasing the incidence of morbidity and mortality associated with bowel cancer in Australia. This will be achieved under a new paradigm for colonoscopy training and implementation of evidence-based practice across the screening pathway and specifically targeting areas highlighted in this thesis. Recommendations for improvement of NBCSP/QBCSP effectiveness and efficiency include the following: 1. Implementation of NBCSP and QBCSP health promotion activities that target men, in particular, to increase FOBT screening uptake. 2. Improved colonoscopy training for trainees and refresher courses or retraining for existing proceduralists to improve completion rates (especially for female NBCSP/QBCSP participants), and polyp and adenoma detection and removal, including newer techniques to detect flat and depressed lesions. 3. Introduction of colonoscopy training initiatives for trainees that are aligned with NBCSP/QBCSP colonoscopy quality indicators, including measurement of training outcomes using objective quality indicators such as caecal intubation, withdrawal time, and adenoma detection rate. 4. Introduction of standardised, interdisciplinary colonoscopy training to reduce apparent differences between specialties with regard to compliance with guideline recommendations, completion rates, and quality of polypectomy. 5. Improved quality of colonoscopy training by adoption of a UK-style training program with centres of excellence, incorporating newer, more objective assessment methods, use of a variety of training tools such as simulation and rotations of trainees between metropolitan, rural, and public and private sector training facilities. 6. Incorporation of NHMRC guidelines into colonoscopy information systems to improve documentation, provide guideline recommendations at the point of care, use of gastroenterology nurse coordinators to facilitate compliance with guidelines and provision of guideline-based colonoscopy referral letters for GPs. 7. Provision of information and education about the NBCSP/QBCSP, bowel cancer risk factors, including family history and polyp surveillance guidelines, for participants, GPs and proceduralists. 8. Improved referral of NBCSP/QBCSP participants found to have a high-risk family history of bowel cancer to appropriate genetics services.

Quality of cause-of-death reporting using ICD-10 drowning codes : a descriptive study of 69 countries

Background: The systematic collection of high-quality mortality data is a prerequisite in designing relevant drowning prevention programmes. This descriptive study aimed to assess the quality (i.e., level of specificity) of cause-of-death reporting using ICD-10 drowning codes across 69 countries.---------- Methods: World Health Organization (WHO) mortality data were extracted for analysis. The proportion of unintentional drowning deaths coded as unspecified at the 3-character level (ICD-10 code W74) and for which the place of occurrence was unspecified at the 4th character (.9) were calculated for each country as indicators of the quality of cause-of-death reporting.---------- Results: In 32 of the 69 countries studied, the percentage of cases of unintentional drowning coded as unspecified at the 3-character level exceeded 50%, and in 19 countries, this percentage exceeded 80%; in contrast, the percentage was lower than 10% in only 10 countries. In 21 of the 56 countries that report 4-character codes, the percentage of unintentional drowning deaths for which the place of occurrence was unspecified at the 4th character exceeded 50%, and in 15 countries, exceeded 90%; in only 14 countries was this percentage lower than 10%.---------- Conclusion: Despite the introduction of more specific subcategories for drowning in the ICD-10, many countries were found to be failing to report sufficiently specific codes in drowning mortality data submitted to the WHO.

The power of a single prototype : sustainable fashion textile design and the prevention of carcinogenic melanoma

Is there a role for prototyping (sketching, pattern making and sampling) in addressing real world problems of sustainability (People, Profit, and Planet), in this case social/healthcare issues, through fashion and textiles research? Skin cancer and related illnesses are a major cause of disfigurement and death in New Zealand and Australia where the rates of Melanoma, a serious form of skin cancer, are four times higher than in the Northern Hemisphere regions of USA, UK and Canada (IARC, 1992). In 2007, AUT University (Auckland University of Technology) Fashion Department and the Health Promotion Department of Cancer Society - Auckland Division (CSA) developed a prototype hat aimed at exploring a barrier type solution to prevent facial and neck skin damage. This is a paradigm shift from the usual medical research model. This paper provides an overview of the project and examines how a fashion prototype has been used to communicate emergent social, environmental, personal, physiological and technological concerns to the trans-disciplinary research team. The authors consider how the design of a product can enhance and support sustainable design practice while contributing a potential solution to an ongoing health issue. Analysis of this case study provides an insight into prototyping in fashion and textiles design, user engagement and the importance of requirements analysis in relation to sustainable development. The analysis and a successful outcome of the final prototype have provided a gateway to future collaborative research and product development.

Health law in Australia

Health Law in Australia is the first book to deal with health law on a comprehensive national basis. In a field of law that is becoming increasingly important and where the demand for expertise is rapidly expanding, Health Law in Australia takes a logical, structured approach to an examination of the law in all Australian jurisdictions. By covering all the major areas in this diverse field of law, Health Law in Australia enhances the understanding of the discipline as a whole. Beginning with an exploration of the general principles of health law, including chapters on “Medical Negligence”, “Children and Consent”, and “Confidentiality, Privacy, and Access to Health Records”, the book goes on to consider beginning-of-life and end-of-life issues before concluding with chapters on emerging areas in health law, such as biotechnology and medical research. The contributing authors include national leaders in the field who are specialists in these areas of health law and who can therefore reveal to readers the results of their research. Health Law in Australia has been written for those with a legal background and is essential reading for undergraduate law students, postgraduate law students, researchers and scholars in the disciplines of law, health and medicine, as well as legal practitioners, government departments and bodies in the health area, and private health providers.

Probabilistic subgroup identification using Bayesian finite mixture modelling : a case study in Parkinson’s disease phenotype identification

This article explores the use of probabilistic classification, namely finite mixture modelling, for identification of complex disease phenotypes, given cross-sectional data. In particular, if focuses on posterior probabilities of subgroup membership, a standard output of finite mixture modelling, and how the quantification of uncertainty in these probabilities can lead to more detailed analyses. Using a Bayesian approach, we describe two practical uses of this uncertainty: (i) as a means of describing a person’s membership to a single or multiple latent subgroups and (ii) as a means of describing identified subgroups by patient-centred covariates not included in model estimation. These proposed uses are demonstrated on a case study in Parkinson’s disease (PD), where latent subgroups are identified using multiple symptoms from the Unified Parkinson’s Disease Rating Scale (UPDRS).

Prognostic modelling options for remaining useful life estimation by industry

Over recent years a significant amount of research has been undertaken to develop prognostic models that can be used to predict the remaining useful life of engineering assets. Implementations by industry have only had limited success. By design, models are subject to specific assumptions and approximations, some of which are mathematical, while others relate to practical implementation issues such as the amount of data required to validate and verify a proposed model. Therefore, appropriate model selection for successful practical implementation requires not only a mathematical understanding of each model type, but also an appreciation of how a particular business intends to utilise a model and its outputs. This paper discusses business issues that need to be considered when selecting an appropriate modelling approach for trial. It also presents classification tables and process flow diagrams to assist industry and research personnel select appropriate prognostic models for predicting the remaining useful life of engineering assets within their specific business environment. The paper then explores the strengths and weaknesses of the main prognostics model classes to establish what makes them better suited to certain applications than to others and summarises how each have been applied to engineering prognostics. Consequently, this paper should provide a starting point for young researchers first considering options for remaining useful life prediction. The models described in this paper are Knowledge-based (expert and fuzzy), Life expectancy (stochastic and statistical), Artificial Neural Networks, and Physical models.

Making sense of dementia : understanding amongst indigenous Australians

Dementia is a growing health and social concern for all Australians. Whilst the prevalence of dementia amongst Australia's indigenous people is unclear, there is some evidence that dementia rates are five times that of the general Australian population. To date no studies have examined dementia knowledge levels in indigenous communities. Purpose of the study: This paper aims to explore indigenous Australians' understanding, knowledge and misconceptions of dementia. Design and methods: Hundered and seventy-four indigenous adults participated in a cross-sectional survey using a modified version of the Alzheimer's Disease Knowledge Test (ADK). The survey included demographic information, two open-ended questions and 20 multiple choice questions. Each ADK item was examined to identify responses that revealed commonly held correct beliefs, knowledge gaps and misconceptions. Results: The overall level of understanding of dementia was poor. Younger participants were significantly more likely to have no knowledge of Alzheimer's Disease, whereas the other age groups were most likely to have at least some knowledge. It was also revealed that there are common misconceptions about Alzheimer's Disease held by both indigenous and non-indigenous communities. Implications: Culturally appropriate awareness campaigns and targeted educational interventions need to be implemented to improve the general level of understanding of dementia in indigenous communities.

A Bayesian approach to assess interaction between known risk factors: The risk of lung cancer from exposure to asbestos and smoking

We review the literature on the combined effect of asbestos exposure and smoking on lung cancer, and explore a Bayesian approach to assess evidence of interaction. Previous approaches have focussed on separate tests for an additive or multiplicative relation. We extend these approaches by exploring the strength of evidence for either relation using approaches which allow the data to choose between both models. We then compare the different approaches.

Producing the magnum opus : A metaphor for nephrology nursing expertise acquisition

Aim. This paper elucidates the nature of metaphor and the conditions necessary to its use as an analytic device in qualitative research, and describes how the use of metaphor assisted in the analytic processes of a grounded theory study of nephrology nursing expertise. Background. The use of metaphor is pervasive in everyday thought, language and action. It is an important means for the comprehension and management of everyday life, and makes challenging or problematic concepts easier to explain. Metaphors are also pervasive in quantitative and qualitative research for the same reason. In both everyday life and in research, their use may be implicit or explicit. Methods. The study using grounded theory methodology took place in one renal unit in New South Wales, Australia between 1999 and 2000 and included six non-expert and 11 expert nurses. It involved simultaneous data collection and analysis using participant observation, semi-structured interviews and review of nursing documentation. Findings. A three stage skills-acquisitive process was identified in which an orchestral metaphor was used to explain the relationships between stages and to satisfactorily capture the data coded within each stage. Conclusion. Metaphors create images, clarify and add depth to meanings and, if used appropriately and explicitly in qualitative research, can capture data at highly conceptual levels. Metaphors also assist in explaining the relationship between findings in a clear and coherent manner. © 2005 Blackwell Publishing Ltd.

The impact of nonlinear exposure risk relationships on seasonal time series data: modelling danish neonatal birth anthropometric data

Background Birth weight and length have seasonal fluctuations. Previous analyses of birth weight by latitude effects identified seemingly contradictory results, showing both 6 and 12 monthly periodicities in weight. The aims of this paper are twofold: (a) to explore seasonal patterns in a large, Danish Medical Birth Register, and (b) to explore models based on seasonal exposures and a non-linear exposure-risk relationship. Methods Birth weight and birth lengths on over 1.5 million Danish singleton, live births were examined for seasonality. We modelled seasonal patterns based on linear, U- and J-shaped exposure-risk relationships. We then added an extra layer of complexity by modelling weighted population-based exposure patterns. Results The Danish data showed clear seasonal fluctuations for both birth weight and birth length. A bimodal model best fits the data, however the amplitude of the 6 and 12 month peaks changed over time. In the modelling exercises, U- and J-shaped exposure-risk relationships generate time series with both 6 and 12 month periodicities. Changing the weightings of the population exposure risks result in unexpected properties. A J-shaped exposure-risk relationship with a diminishing population exposure over time fitted the observed seasonal pattern in the Danish birth weight data. Conclusion In keeping with many other studies, Danish birth anthropometric data show complex and shifting seasonal patterns. We speculate that annual periodicities with non-linear exposure-risk models may underlie these findings. Understanding the nature of seasonal fluctuations can help generate candidate exposures.