291 research outputs found

    Multivariate risks and depth-trimmed regions

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    We describe a general framework for measuring risks, where the risk measure takes values in an abstract cone. It is shown that this approach naturally includes the classical risk measures and set-valued risk measures and yields a natural definition of vector-valued risk measures. Several main constructions of risk measures are described in this abstract axiomatic framework. It is shown that the concept of depth-trimmed (or central) regions from the multivariate statistics is closely related to the definition of risk measures. In particular, the halfspace trimming corresponds to the Value-at-Risk, while the zonoid trimming yields the expected shortfall. In the abstract framework, it is shown how to establish a both-ways correspondence between risk measures and depth-trimmed regions. It is also demonstrated how the lattice structure of the space of risk values influences this relationship.Comment: 26 pages. Substantially revised version with a number of new results adde

    We need to talk about manels: the problem of implicit gender bias in sport and exercise medicine.

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    In 2015, a website (www.allmalepanels.tumblr. com/) began documenting instances of all-male panels (colloquially known as a ‘manel’). This, along with the Twitter hashtag #manel, has helped drive recognition of the persistent and pervasive gender bias in the composition of experts assembled to present at conferences and other events. Recent social media discussions have similarly highlighted the prevalence of all-male panels in Sport and Exercise Medicine (SEM). While, to our knowledge, all-male panel trends in SEM have not yet formally been documented or published, one need look no further than SEM conference committees, keynote speaker lists, panels and other events to see that it exists in practice. Why, in 2018, is SEM and its related disciplines still failing to identify and acknowledge the role that implicit bias plays in the very structure of our own research, practice and education? SEM is, after all, a profession that contains experts, and serves populations, of all genders. This editorial will introduce the definition, implications and manifestations of implicit gender bias and then explore how the SEM community can begin to address this issue, advance the discussion and develop a more equitable global community

    Using a pragmatically adapted, low-cost contingency management intervention to promote heroin abstinence in individuals undergoing treatment for heroin use disorder in UK drug services (PRAISE): a cluster randomised trial

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    Introduction: Most individuals treated for heroin use disorder receive opioid agonist treatment (OAT)(methadone or buprenorphine). However, OAT is associated with high attrition and persistent, occasional heroin use. There is some evidence for the effectiveness of contingency management (CM), a behavioural intervention involving modest financial incentives, in encouraging drug abstinence when applied adjunctively with OAT. UK drug services have a minimal track record of applying CM and limited resources to implement it. We assessed a CM intervention pragmatically adapted for ease of implementation in UK drug services to promote heroin abstinence among individuals receiving OAT. Design: Cluster randomised controlled trial. Setting and participants: 552 adults with heroin use disorder (target 660) enrolled from 34 clusters (drug treatment clinics) in England between November 2012 and October 2015. Interventions: Clusters were randomly allocated 1:1:1 to OAT plus 12× weekly appointments with: (1) CM targeted at opiate abstinence at appointments (CM Abstinence); (2) CM targeted at on-time attendance at appointments (CM Attendance); or (3) no CM (treatment as usual; TAU). Modifications included monitoring behaviour weekly and fixed incentives schedule. Measurements: Primary outcome: heroin abstinence measured by heroin-free urines (weeks 9–12). Secondary outcomes: heroin abstinence 12 weeks after discontinuation of CM (weeks 21–24); attendance; self-reported drug use, physical and mental health. Results: CM Attendance was superior to TAU in encouraging heroin abstinence. Odds of a heroin-negative urine in weeks 9–12 was statistically significantly greater in CM Attendance compared with TAU (OR=2.1; 95% CI 1.1 to 3.9; p=0.030). CM Abstinence was not superior to TAU (OR=1.6; 95% CI 0.9 to 3.0; p=0.146) or CM Attendance (OR=1.3; 95% CI 0.7 to 2.4; p=0.438) (not statistically significant differences). Reductions in heroin use were not sustained at 21–24 weeks. No differences between groups in self-reported heroin use. Conclusions: A pragmatically adapted CM intervention for routine use in UK drug services was moderately effective in encouraging heroin abstinence compared with no CM only when targeted at attendance. CM targeted at abstinence was not effective. Trial registration number: ISRCTN 01591254

    Positive reinforcement targeting abstinence in substance misuse (PRAISe): Study protocol for a Cluster RCT & process evaluation of contingency management

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    There are approximately 256,000 heroin and other opiate users in England of whom 155,000 are in treatment for heroin (or opiate) addiction. The majority of people in treatment receive opiate substitution treatment (OST) (methadone and buprenorphine). However, OST suffers from high attrition and persistent heroin use even whilst in treatment. Contingency management (CM) is a psychological intervention based on the principles of operant conditioning. It is delivered as an adjunct to existing evidence based treatments to amplify patient benefit and involves the systematic application of positive reinforcement (financial or material incentives) to promote behaviours consistent with treatment goals. With an international evidence base for CM, NICE recommended that CM be implemented in UK drug treatment settings alongside OST to target attendance and the reduction of illicit drug use. While there was a growing evidence base for CM, there had been no examination of its delivery in UK NHS addiction services. The PRAISe trial evaluates the feasibility, acceptability, clinical and cost effectiveness of CM in UK addiction services. It is a cluster randomised controlled effectiveness trial of CM (praise and financial incentives) targeted at either abstinence from opiates or attendance at treatment sessions versus no CM among individuals receiving OST. The trial includes an economic evaluation which explores the relative costs and cost effectiveness of the two CM intervention strategies compared to TAU and an embedded process evaluation to identify contextual factors and causal mechanisms associated with variations in outcome. This study will inform UK drug treatment policy and practice. Trial registration ISRCTN 01591254

    Classifying radiographic changes of the pubic symphysis in male athletes: Development and reproducibility of a new scoring protocol

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    Purpose: To develop a specified radiographic scoring system for the pubic symphysis and adjacent bones, and to examine the intra- and inter-rater reproducibility of this system. Method: Development of the scoring protocol was performed in three stages using AP pelvis radiographs of 102 male adult athlet
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