Risk of discharge against medical advice among hospital inpatients with a history of opioid agonist therapy in New South Wales, Australia: a cohort study and nested crossover-cohort analysis

Background: People who use illicit opioids have high rates of hospital admission. We aimed to measure the risk of discharge against medical advice among inpatients with a history of opioid agonist therapy (OAT), and test whether OAT is associated with lower risk of discharge against medical advice. Methods: We conducted a cohort study of patients admitted to hospital in an emergency between 1 August 2001 and 30 April 2018 in New South Wales, Australia. All patients had a previous episode of OAT in the community. The main outcome was discharge against medical advice, and the main exposure was whether patients had an active OAT permit at the time of admission. Results: 14,035/116,957 admissions (12 %) ended in discharge against medical advice. Admissions during periods of OAT had 0.79 (0.76−0.83; p < 0.001) times the risk of discharge against medical advice, corresponding to an absolute risk reduction of 3.0 percentage points. Risk of discharge against medical advice was higher among patients who were younger, male, identified as Aboriginal and/or Torres Strait Islander, and those admitted for accidents, drug-related reasons, or injecting-related injuries (such as cutaneous abscesses). In a subsample of 7793 patients included in a crossover-cohort analysis, OAT was associated with 0.84 (95 % CI 0.76−0.93; p < 0.001) times the risk of discharge against medical advice. Conclusions: Among patients with a history of OAT, one in eight emergency hospital admissions ends in discharge against medical advice. OAT enrolment at the time of admission is associated with a reduction of this risk

“There’s a big tag on my head”: exploring barriers to treatment seeking with women who use methamphetamine in Sydney, Australia

Background: Australia has a high prevalence of regular use of methamphetamine. While half of people who use methamphetamine regularly are women, they make up only one third of people seeking treatment for methamphetamine use disorder. There is a lack of qualitative research into the facilitators and barriers to treatment for women who use methamphetamine regularly. The study seeks a better understanding of the experiences and treatment preferences of women who use methamphetamine, to inform person-centred changes in practice and policy that break down barriers to treatment. Methods: We conducted semi-structured interviews with 11 women who frequently use methamphetamine (at least once a week), and who are not engaged in treatment. Women were recruited from health services surrounding a stimulant treatment centre at an inner-city hospital. Participants were asked about their methapmhetamine use and health service needs and preferences. Thematic analysis was completed using Nvivo® software. Results: Three themes were developed from participants’ responses around experiences of regular methamphetamine use and treatment needs: 1. Resistance of stigmatised identity including dependence; 2. Interpersonal violence; 3. Institutionalised stigma. A fourth set of themes on service delivery preferences were also elicited, including continuity of care, integrated health care, and provision of non-judgmental services. Conclusion: Gender-inclusive health care services for people who use methamphetamine should actively work to address stigma, support a relational approach to assessment and treatment, and seek to provide structurally competent health care that is trauma and violence informed, and integrated with other services. Findings may also have application for substance use disorders other than methamphetamine

Estimating the functional form for the density dependence from life history data

Two contrasting approaches to the analysis of population dynamics are currently popular: demographic approaches where the associations between demographic rates and statistics summarizing the population dynamics are identified; and time series approaches where the associations between population dynamics, population density, and environmental covariates are investigated. In this paper, we develop an approach to combine these methods and apply it to detailed data from Soay sheep (Ovis aries). We examine how density dependence and climate contribute to fluctuations in population size via age- and sex-specific demographic rates, and how fluctuations in demographic structure influence population dynamics. Density dependence contributes most, followed by climatic variation, age structure fluctuations and interactions between density and climate. We then simplify the density-dependent, stochastic, age-structured demographic model and derive a new phenomenological time series which captures the dynamics better than previously selected functions. The simple method we develop has potential to provide substantial insight into the relative contributions of population and individual-level processes to the dynamics of populations in stochastic environments

Short-Range Ising Spin Glass: Multifractal Properties

The multifractal properties of the Edwards-Anderson order parameter of the short-range Ising spin glass model on d=3 diamond hierarchical lattices is studied via an exact recursion procedure. The profiles of the local order parameter are calculated and analysed within a range of temperatures close to the critical point with four symmetric distributions of the coupling constants (Gaussian, Bimodal, Uniform and Exponential). Unlike the pure case, the multifractal analysis of these profiles reveals that a large spectrum of the $\alpha$-H\"older exponent is required to describe the singularities of the measure defined by the normalized local order parameter, at and below the critical point. Minor changes in these spectra are observed for distinct initial distributions of coupling constants, suggesting an universal spectra behavior. For temperatures slightly above T_{c}, a dramatic change in the $F(\alpha)$ function is found, signalizing the transition.Comment: 8 pages, LaTex, PostScript-figures included but also available upon request. To be published in Physical Review E (01/March 97

Health and social characteristics of clients reporting amphetamine type substance use at entry to public alcohol and other drug services in New South Wales, Australia, 2016–2019

Introduction: Amphetamine type substances (ATS) are commonly used by Australian alcohol and other drug service entrants. We describe demographic characteristics, patterns of ATS and other substance use, health and social conditions among clients entering New South Wales (NSW) public alcohol and other drug services. Methods: Retrospective cohort of 13,864 records across six health districts (2016–2019) for clients seeking substance use treatment. These districts service approximately 44% of the NSW population aged 15 years and over. Multivariate analysis was conducted on a subsample for whom full data were available (N = 9981). Data included NSW Minimum Data Set for drug and alcohol treatment services and Australian Treatment Outcomes Profile items. Results: Over the preceding 4 weeks, 77% (n = 10,610) of clients (N = 13,864) reported no recent ATS use, 15% (n = 2109) reported ‘low frequency’ (1–12 days) and 8% (n = 1145) ‘high frequency’ (13–28 days) use. ATS use was most common among people attending for ATS or opioids as primary drug of concern. A multinomial regression (N = 9981) identified that clients reporting recent arrest (aOR 1.74, 95% CI 1.36, 2.24), higher cannabis use frequency (aOR 1.01, 95% CI 1.00, 1.02), lower opioid use frequency (aOR 0.98, 95% CI 0.97, 0.99) and poorer quality of life (aOR 0.91, 95% CI 0.86, 0.97) were more likely to report ‘high frequency’ rather than ‘low frequency’ ATS use. Discussion and Conclusions: People who use ATS experience health and social issues that may require targeted responses. These should be integrated across all services, not only for clients with ATS as principal drug of concern

Integrating evolution into ecological modelling: accommodating phenotypic changes in agent based models.

PMCID: PMC3733718This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Evolutionary change is a characteristic of living organisms and forms one of the ways in which species adapt to changed conditions. However, most ecological models do not incorporate this ubiquitous phenomenon. We have developed a model that takes a 'phenotypic gambit' approach and focuses on changes in the frequency of phenotypes (which differ in timing of breeding and fecundity) within a population, using, as an example, seasonal breeding. Fitness per phenotype calculated as the individual's contribution to population growth on an annual basis coincide with the population dynamics per phenotype. Simplified model variants were explored to examine whether the complexity included in the model is justified. Outputs from the spatially implicit model underestimated the number of individuals across all phenotypes. When no phenotype transitions are included (i.e. offspring always inherit their parent's phenotype) numbers of all individuals are always underestimated. We conclude that by using a phenotypic gambit approach evolutionary dynamics can be incorporated into individual based models, and that all that is required is an understanding of the probability of offspring inheriting the parental phenotype

Environmental Predictors of Diversity in Recent Planktonic Foraminifera as Recorded in Marine Sediments

© 2016 Fenton et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. [4.0 license]. The attached file is the published version of the article

Is reproductive strategy a key factor in understanding the evolutionary history of Southern Ocean Asteroidea (Echinodermata)?

Life traits such as reproductive strategy can be determining factors of species evolutionary history and explain the resulting diversity patterns. This can be investigated using phylogeographic analyses of genetic units. In this work, the genetic structure of five asteroid genera with contrasting reproductive strategies (brooding: Diplasterias, Notasterias and Lysasterias versus broadcasting: Psilaster and Bathybiaster) was investigated in the Southern Ocean. Over 1,400 mtDNA cytochrome C oxidase subunit I (COI) sequences were analysed using five species delineation methods (ABGD, ASAP, mPTP, sGMYC and mGMYC), two phylogenetic reconstructions (ML and BA), and molecular clock calibrations, in order to examine the weight of reproductive strategy in the observed differences among phylogeographic patterns. We hypothesised that brooding species would show higher levels of genetic diversity and species richness along with a clearer geographic structuring than broadcasting species. In contrast, genetic diversity and species richness were not found to be significantly different between brooders and broadcasters, but broadcasters are less spatially structured than brooders supporting our initial hypothesis and suggesting more complex evolutionary histories associated to this reproductive strategy. Broadcasters' phylogeography can be explained by different scenarios including deep‐sea colonisation routes, bipolarity or cosmopolitanism, and sub‐Antarctic emergence for the genus Bathybiaster; Antarctic‐ New Zealand faunal exchanges across the Polar Front for the genus Psilaster. Brooders' phylogeography could support the previously formulated hypothesis of a past trans‐Antarctic seaway established between the Ross and the Weddell seas during the Plio‐Pleistocene. Our results also show, for the first time, that the Weddell Sea is populated by a mixed asteroid fauna originating from both the East and West Antarctic

A web-based therapeutic program (We Can Do This) for reducing methamphetamine use and increasing help-seeking among Aboriginal and Torres Strait Islander people: Protocol for a randomized wait-list control trial

Background: Methamphetamine use is of deep concern to Aboriginal and Torres Strait Islander communities, but access to culturally appropriate treatment resources and services is limited. Web-based programs have potential as flexible and cost-effective additions to the range of treatment options available to Aboriginal people. The We Can Do This online intervention is designed to incorporate evidence-based therapies in a culturally relevant format using narratives from Aboriginal people to contextualize the therapeutic content. Objective: The goal of the research will be to test the effectiveness of the online intervention in a wait-list controlled randomized trial across multiple sites in urban, regional, and remote locations. Methods: Participants will be Aboriginal and Torres Strait Islander people aged 16 years and over who have used methamphetamine at least weekly for the previous 3 months. They will be recruited online and via health services. During the intervention phase, participants will have access to the online intervention for 6 weeks with optional telephone or face-to-face support provided by participating health services. The primary outcome measure will be the number of days the participant used methamphetamine over the past 4 weeks compared to wait-list controls, assessed at baseline, 1, 2, and 3 months. Secondary outcomes will include help-seeking, readiness to change, severity of dependence, and psychological distress. Any important changes to the protocol will be agreed upon by the trial management committee and communicated to all relevant parties, including trial site representatives and the trial registry. Results: Recruitment will commence in July 2019, and results are expected in early 2021. This research is funded by National Health and Medical Research Council project grant #1100696. The primary sponsor for the trial is the South Australian Health and Medical Research Institute. A trial management committee with representation from the participating health services, chief investigators, other Aboriginal experts, and consumers will oversee procedures, trial conduct, analysis, and reporting of the results. Conclusions: The trial of this online intervention builds on existing research supporting the effectiveness of Web-based therapies for a range of psychological and other health-related issues including substance use. If successful, the We Can Do this online intervention will increase the range of options available to Aboriginal people seeking to reduce or stop methamphetamine use. It may provide a pathway into treatment for people who may otherwise be disengaged with health services for a range of reasons and will be a culturally appropriate, evidence-based resource for health practitioners to offer their clients. Trial Registration: Australian New Zealand Clinical Trials Registry ACTRN12619000134123p; https://www.anzctr.org.au/ Trial/Registration/TrialReview.aspx?id=376088&isReview=true International Registered Report Identifier (IRRID): PRR1-10.2196/14084Rachel Reilly, Rebecca McKetin, Handan Wand, Julia Butt, Matthew Smout, Nadine Ezard, Katherine Conigrave, Yvonne Clark, Brendan Quinn, Carla Treloar, Dennis Gray, Adrian Dunlop, Yvette Roe, James War

Inferring transient dynamics of human populations from matrix non-normality

This is the final version of the article. Available from Springer Verlag via the DOI in this record.In our increasingly unstable and unpredictable world, population dynamics rarely settle uniformly to long-term behaviour. However, projecting period-by-period through the preceding fluctuations is more data-intensive and analytically involved than evaluating at equilibrium. To efficiently model populations and best inform policy, we require pragmatic suggestions as to when it is necessary to incorporate short-term transient dynamics and their effect on eventual projected population size. To estimate this need for matrix population modelling, we adopt a linear algebraic quantity known as non-normality. Matrix non-normality is distinct from normality in the Gaussian sense, and indicates the amplificatory potential of the population projection matrix given a particular population vector. In this paper, we compare and contrast three well-regarded metrics of non-normality, which were calculated for over 1000 age-structured human population projection matrices from 42 European countries in the period 1960 to 2014. Non-normality increased over time, mirroring the indices of transient dynamics that peaked around the millennium. By standardising the matrices to focus on transient dynamics and not changes in the asymptotic growth rate, we show that the damping ratio is an uninformative predictor of whether a population is prone to transient booms or busts in its size. These analyses suggest that population ecology approaches to inferring transient dynamics have too often relied on suboptimal analytical tools focussed on an initial population vector rather than the capacity of the life cycle to amplify or dampen transient fluctuations. Finally, we introduce the engineering technique of pseudospectra analysis to population ecology, which, like matrix non-normality, provides a more complete description of the transient fluctuations than the damping ratio. Pseudospectra analysis could further support non-normality assessment to enable a greater understanding of when we might expect transient phases to impact eventual population dynamics.This work was funded by Wellcome Trust New Investigator 103780 to TE, who is also funded by NERC Fellowship NE/J018163/1. JB gratefully acknowledges the ESRC Centre for Population Change ES/K007394/1