1,848 research outputs found

    Over 1200 drugs-related deaths and 190,000 opiate-user-years of follow-up : relative risks by sex and age-group

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    Heroin users/injectors' risk of drugs-related death by sex and current age is weakly estimated both in individual cohorts of under 1000 clients, 5000 person-years or 50 drugs-related deaths and when using cross-sectional data. A workshop in Cambridge analysed six cohorts who were recruited according to a common European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) protocol from drug treatment agencies in Barcelona, Denmark, Dublin, Lisbon, Rome and Vienna in the 1990s; and, as external reference, opiate-user arrestees in France and hepatitis C diagnosed ever-injectors in Scotland in 1993-2001, both followed by database linkage to December 2001. EMCDDA cohorts recorded approximately equal numbers of drugs-related deaths (864) and deaths from other non-HIV causes (865) during 106,152 person-years of follow-up. External cohorts contributed 376 drugs-related deaths (Scotland 195, France 181) and 418 deaths from non-HIV causes (Scotland 221, France 197) during 86,417 person-years of follow-up (Scotland 22,670, France 63,747). EMCDDA cohorts reported 707 drugs-related deaths in 81,367 man-years {8.7 per 1000 person-years, 95% CI: 8.1 to 9.4} but only 157 in 24,785 person-years for females {6.3 per 1000 person-years, 95% CI: 5.4 to 7.4}. Except in external cohorts, relative risks by current age-group were not particularly strong, and more modest in Poisson regression than in cross-sectional analyses: relative risk was 1.2 (95% CI: 1.0-1.4) for 35-44 year olds compared to 15-24 year 3 olds, but 1.4 for males (95%CI: 1.2-1.6), and dramatically lower at 0.44 after the first year of follow-up (95% CI: 0.37-0.52)

    The Impact of Study Size on Meta-analyses: Examination of Underpowered Studies in Cochrane Reviews

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    Background: Most meta-analyses include data from one or more small studies that, individually, do not have power to detect an intervention effect. The relative influence of adequately powered and underpowered studies in published metaanalyses has not previously been explored. We examine the distribution of power available in studies within meta-analyses published in Cochrane reviews, and investigate the impact of underpowered studies on meta-analysis results. Methods and Findings: For 14,886 meta-analyses of binary outcomes from 1,991 Cochrane reviews, we calculated power per study within each meta-analysis. We defined adequate power as $50% power to detect a 30% relative risk reduction. In a subset of 1,107 meta-analyses including 5 or more studies with at least two adequately powered and at least one underpowered, results were compared with and without underpowered studies. In 10,492 (70%) of 14,886 meta-analyses, all included studies were underpowered; only 2,588 (17%) included at least two adequately powered studies. 34% of the metaanalyses themselves were adequately powered. The median of summary relative risks was 0.75 across all meta-analyses (inter-quartile range 0.55 to 0.89). In the subset examined, odds ratios in underpowered studies were 15% lower (95% CI 11% to 18%, P,0.0001) than in adequately powered studies, in meta-analyses of controlled pharmacological trials; and 12% lower (95% CI 7% to 17%, P,0.0001) in meta-analyses of controlled non-pharmacological trials. The standard error of the intervention effect increased by a median of 11% (inter-quartile range 21% to 35%) when underpowered studies were omitted; and between-study heterogeneity tended to decrease. Conclusions: When at least two adequately powered studies are available in meta-analyses reported by Cochrane reviews, underpowered studies often contribute little information, and could be left out if a rapid review of the evidence is required. However, underpowered studies made up the entirety of the evidence in most Cochrane reviews

    Transoral laser surgery for laryngeal carcinoma: has Steiner achieved a genuine paradigm shift in oncological surgery?

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    Transoral laser microsurgery applies to the piecemeal removal of malignant tumours of the upper aerodigestive tract using the CO2 laser under the operating microscope. This method of surgery is being increasingly popularised as a single modality treatment of choice in early laryngeal cancers (T1 and T2) and occasionally in the more advanced forms of the disease (T3 and T4), predomi- nantly within the supraglottis. Thomas Kuhn, the American physicist turned philosopher and historian of science, coined the phrase ‘paradigm shift’ in his groundbreaking book The Structure of Scientific Revolutions. He argued that the arrival of the new and often incompatible idea forms the core of a new paradigm, the birth of an entirely new way of thinking. This article discusses whether Steiner and col- leagues truly brought about a paradigm shift in oncological surgery. By rejecting the principle of en block resection and by replacing it with the belief that not only is it oncologically safe to cut through the substance of the tumour but in doing so one can actually achieve better results, Steiner was able to truly revolutionise the man- agement of laryngeal cancer. Even though within this article the repercussions of his insight are limited to the upper aerodigestive tract oncological surgery, his willingness to question other peoples’ dogma makes his contribution truly a genuine paradigm shift

    Methods for delivering the UK's multi-centre prison-based naloxone-on-release pilot randomised trial (N-ALIVE): Europe's largest prison-based randomised controlled trial

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    INTRODUCTION AND AIMS: Naloxone is an opioid antagonist used for emergency resuscitation following opioid overdose. Prisoners with a history of heroin use by injection have a high risk of drug-related death in the first weeks after prison-release. The N-ALIVE trial was planned as a large prison-based randomised controlled trial (RCT) to test the effectiveness of naloxone-on-release in the prevention of fatal opiate overdoses soon after release. The N-ALIVE pilot trial was conducted to test the main trial's assumptions on recruitment of prisons and prisoners, and the logistics for ensuring that participants received their N-ALIVE pack on release. DESIGN AND METHODS: Adult prisoners who had ever injected heroin, were incarcerated for ≥7 days and were expected to be released within 3 months were eligible. Participants were randomised to receive, on liberation, a pack containing a single 'rescue' injection of naloxone or a control pack with no naloxone syringe. The trial was double-blind prior to prison-release. RESULTS: We randomised 1685 prisoners (842 naloxone; 843 control) across 16 prisons in England. We stopped randomisation on 8 December 2014 because only one-third of administrations of naloxone-on-release were to the randomised ex-prisoner; two-thirds were to others whom we were not tracing. DISCUSSION AND CONCLUSIONS: Prevention RCTs are seldom conducted within prisons; we demonstrated the feasibility of conducting a multi-prison RCT to prevent fatality from opioid overdose in the outside community. We terminated the N-ALIVE trial due to the infeasibility of individualised randomisation to naloxone-on-release. Large RCTs are feasible within prisons

    Drugs-related death soon after hospital discharge among drug treatment clients in Scotland:record linkage, validation and investigation of risk factors.

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    We validate that the 28 days after hospital-discharge are high-risk for drugs-related death (DRD) among drug users in Scotland and investigate key risk-factors for DRDs soon after hospital-discharge. Using data from an anonymous linkage of hospitalisation and death records to the Scottish Drugs Misuse Database (SDMD), including over 98,000 individuals registered for drug treatment during 1 April 1996 to 31 March 2010 with 705,538 person-years, 173,107 hospital-stays, and 2,523 DRDs. Time-at-risk of DRD was categorised as: during hospitalization, within 28 days, 29-90 days, 91 days-1 year, >1 year since most recent hospital discharge versus 'never admitted'. Factors of interest were: having ever injected, misuse of alcohol, length of hospital-stay (0-1 versus 2+ days), and main discharge-diagnosis. We confirm SDMD clients' high DRD-rate soon after hospital-discharge in 2006-2010. DRD-rate in the 28 days after hospital-discharge did not vary by length of hospital-stay but was significantly higher for clients who had ever-injected versus otherwise. Three leading discharge-diagnoses accounted for only 150/290 DRDs in the 28 days after hospital-discharge, but ever-injectors for 222/290. Hospital-discharge remains a period of increased DRD-vulnerability in 2006-2010, as in 1996-2006, especially for those with a history of injecting

    Extending acoustic in‐line pipe rheometry and friction factor modelling to low‐Reynolds‐number, non‐Newtonian slurries

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    The rheology of non‐Newtonian slurries are measured in a recirculating pipe loop using an acoustic velocimetry‐pressure drop technique at very low flow rates and variable solids loadings. The technique avoids (a) settling at low solids concentration, a shortcoming of bench rheometry, by using a vertical test section, and (b) physical sampling, providing greater safety. Speed of sound in the suspensions is also modelled. In‐line and off‐line data are used to assess the suitability of several non‐Newtonian models to describe observed flow behaviour. Measured and predicted values of the friction factor are compared, with the Madlener et al. (2009) Herschel‐Bulkley Extended model found to be superior. The dependence of yield stress and viscosity on solids loading and particle size is investigated, showing complexities from aggregation on the particle size distribution require more interpretation than the choice of rheological or friction‐factor model

    Randomized controlled pilot trial of naloxone-on-release to prevent post-prison opioid overdose deaths

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    BACKGROUND AND AIMS: Naloxone is an opioid antagonist used for emergency resuscitation following opioid overdose. Prisoners with a history of heroin injection have a high risk of drug-related death soon after release from prison. The NALoxone InVEstigation (N-ALIVE) pilot trial (ISRCTN34044390) tested feasibility measures for randomized provision of naloxone-on-release (NOR) to eligible prisoners in England. DESIGN: Parallel-group randomized controlled pilot trial. SETTING: English prisons. PARTICIPANTS: A total of 1685 adult heroin injectors, incarcerated for at least 7 days pre-randomization, release due within 3 months and more than 6 months since previous N-ALIVE release. INTERVENTION: Using 1 : 1 minimization, prisoners were randomized to receive on release a pack containing either a single ‘rescue’ injection of naloxone or a control pack with no syringe. MEASUREMENTS: Key feasibility outcomes were tested against prior expectations: on participation (14 English prisons; 2800 prisoners), consent (75% for randomization), returned prisoner self-questionnaires (RPSQs: 207), NOR-carriage (75% in first 4 weeks) and overdose presence (80%). FINDINGS: Prisons (16) and prisoners (1685) were willing to participate [consent rate, 95% confidence interval (CI) = 70–74%]; 218 RPSQs were received; NOR-carriage (95% CI = 63–79%) and overdose presence (95% CI = 75–84%) were as expected. We randomized 842 to NOR and 843 to control during 30 months but stopped early, because only one-third of NOR administrations were to the ex-prisoner. Nine deaths within 12 weeks of release were registered for 1557 randomized participants released before 9 December 2014. CONCLUSIONS: Large randomized trials are feasible with prison populations. Provision of take-home emergency naloxone prior to prison release may be a life-saving interim measure to prevent heroin overdose deaths among ex-prisoners and the wider population.The pilot N-ALIVE Trial was grant-funded by the Medical Research Council (MC_G0800012) and coordinated by the MRC Clinical Trials Unit at University College London, which core-funds M.K.B.P., L.C. and A.M.M. S.M.B. was funded by Medical Research Council programme number MC_U105260794. J.S. is core-funded by his university, King’s College London. The MRC’s funding board had no role in data analysis, data interpretation, or writing of the report

    Optimal use of reminders: Metacognition, effort, and cognitive offloading

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    Individuals frequently choose between accomplishing goals using unaided cognitive abilities or offloading cognitive demands onto external tools and resources. For example, in order to remember an upcoming appointment one might rely on unaided memory or create a reminder by setting a smartphone alert. Setting a reminder incurs both a cost (the time/effort to set it up) and a benefit (increased likelihood of remembering). Here we investigate whether individuals weigh such costs/benefits optimally or show systematic biases. In 3 experiments, participants performed a memory task where they could choose between (a) earning a maximum reward for each remembered item, using unaided memory; or (b) earning a lesser amount per item, using external reminders to increase the number remembered. Participants were significantly biased toward using external reminders, even when they had a financial incentive to choose optimally. Individual differences in this bias were stable over time, and predicted by participants' erroneous metacognitive underconfidence in their memory abilities. Bias was eliminated, however, when participants received metacognitive advice about which strategy was likely to maximize performance. Furthermore, we found that metacognitive interventions (manipulation of feedback valence and practice-trial difficulty) yielded shifts in participants' reminder bias that were mediated by shifts in confidence. However, the bias could not be fully attributed to metacognitive error. We conclude that individuals have stable biases toward using external versus internal cognitive resources, which result at least in part from inaccurate metacognitive evaluations. Finding interventions to mitigate these biases can improve individuals' adaptive use of cognitive tools

    Genome-Wide Mapping of DNA Methylation 5mC by Methylated DNA Immunoprecipitation (MeDIP)-Sequencing Methods and Protocols

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    Methylated DNA immunoprecipitation is a large scale purification technique. It enables the isolation of methylated DNA fragments for subsequent locus-specific or genome-wide analysis. Here we describe an immunoprecipitation protocol using a monoclonal mouse anti 5-methyl-cytidine antibody followed by next-generation sequencing (MeDIP-Seq)
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