732 research outputs found

    The Relationship Between HR Practices and Firm Performance: Examining Causal Order

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    Significant research attention has been devoted to examining the relationship between HR practices and firm performance, and the research support has assumed HR as the causal variable. Using data from 45 business units (with 62 data points), this study examines how measures of HR practices correlate with past, concurrent, and future operational performance measures. The results indicate that correlations with performance measures at all three times are both high and invariant, and that controlling for past or concurrent performance virtually eliminates the correlation of HR with future performance. Implications are discussed

    Preferred reporting items for studies mapping onto preference-based outcome measures: The MAPS statement

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    'Mapping' onto generic preference-based outcome measures is increasingly being used as a means of generating health utilities for use within health economic evaluations. Despite publication of technical guides for the conduct of mapping research, guidance for the reporting of mapping studies is currently lacking. The MAPS (MApping onto Preference-based measures reporting Standards) statement is a new checklist, which aims to promote complete and transparent reporting of mapping studies. The primary audiences for the MAPS statement are researchers reporting mapping studies, the funders of the research, and peer reviewers and editors involved in assessing mapping studies for publication. A de novo list of 29 candidate reporting items and accompanying explanations was created by a working group comprised of six health economists and one Delphi methodologist. Following a two-round, modified Delphi survey with representatives from academia, consultancy, health technology assessment agencies and the biomedical journal editorial community, a final set of 23 items deemed essential for transparent reporting, and accompanying explanations, was developed. The items are contained in a user friendly 23 item checklist. They are presented numerically and categorised within six sections, namely: (i) title and abstract; (ii) introduction; (iii) methods; (iv) results; (v) discussion; and (vi) other. The MAPS statement is best applied in conjunction with the accompanying MAPS explanation and elaboration document. It is anticipated that the MAPS statement will improve the clarity, transparency and completeness of reporting of mapping studies. To facilitate dissemination and uptake, the MAPS statement is being co-published by eight health economics and quality of life journals, and broader endorsement is encouraged. The MAPS working group plans to assess the need for an update of the reporting checklist in five years' time. This statement was published jointly in Applied Health Economics and Health Policy, Health and Quality of Life Outcomes, International Journal of Technology Assessment in Health Care, Journal of Medical Economics, Medical Decision Making, PharmacoEconomics, and Quality of Life Research

    Development and internal validation of a clinical rule to improve antibiotic use in children presenting to primary care with acute respiratory tract infection and cough: a prognostic cohort study

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    BACKGROUND: Antimicrobial resistance is a serious threat to public health, with most antibiotics prescribed in primary care. General practitioners (GPs) report defensive antibiotic prescribing to mitigate perceived risk of future hospital admission in children with respiratory tract infections. We developed a clinical rule aimed to reduce clinical uncertainty by stratifying risk of future hospital admission. METHODS: 8394 children aged between 3 months and 16 years presenting with acute cough (for ≤28 days) and respiratory tract infection were recruited to a prognostic cohort study from 247 general practitioner practices in England. Exposure variables included demographic characteristics, parent-reported symptoms, and physical examination signs. The outcome was hospital admission for respiratory tract infection within 30 days, collected using a structured, blinded review of medical records. FINDINGS: 8394 (100%) children were included in the analysis, with 78 (0·9%, 95% CI 0·7%-1·2%) admitted to hospital: 15 (19%) were admitted on the day of recruitment (day 1), 33 (42%) on days 2-7; and 30 (39%) on days 8-30. Seven characteristics were independently associated (p<0·01) with hospital admission: age <2 years, current asthma, illness duration of 3 days or less, parent-reported moderate or severe vomiting in the previous 24 h, parent-reported severe fever in the previous 24 h or a body temperature of 37·8°C or more at presentation, clinician-reported intercostal or subcostal recession, and clinician-reported wheeze on auscultation. The area under the receiver operating characteristic (AUROC) curve for the coefficient-based clinical rule was 0·82 (95% CI 0·77-0·87, bootstrap validated 0·81). Assigning one point per characteristic, a points-based clinical rule consisting of short illness, temperature, age, recession, wheeze, asthma, and vomiting (mnemonic STARWAVe; AUROC 0·81, 0·76-0·85) distinguished three hospital admission risk strata: very low (0·3%, 0·2-0·4%) with 1 point or less, normal (1·5%, 1·0-1·9%) with 2 or 3 points, and high (11·8%, 7·3-16·2%) with 4 points or more. INTERPRETATION: Clinical characteristics can distinguish children at very low, normal, and high risk of future hospital admission for respiratory tract infection and could be used to reduce antibiotic prescriptions in primary care for children at very low risk. FUNDING: National Institute for Health Research (NIHR)

    Percutaneous versus surgical strategy for tracheostomy: protocol for a systematic review and meta-analysis of perioperative and postoperative complications

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    Background: Tracheostomy is one of the most frequently performed procedures in intensive care medicine. The two main approaches to form a tracheostoma are the open surgical tracheotomy (ST) and the interventional strategy of percutaneous dilatational tracheotomy (PDT). It is particularly important to the critically ill patients that both procedures are performed with high success rates and low complication frequencies. Therefore, the aim of this systematic review is to summarize and analyze existing and relevant evidence for peri- and postoperative parameters of safety. Methods/design: A systematic literature search will be conducted in The Cochrane Library, MEDLINE, LILACS, and Embase to identify all randomized controlled trials (RCTs) comparing peri- and postoperative complications between the two strategies and to define the strategy with the lower risk of potentially life-threatening events. A priori defined data will be extracted from included studies, and methodological quality will be assessed according to the recommendations of the Cochrane Collaboration. Discussion: The findings of this systematic review with proportional meta-analysis will help to identify the strategy with the lowest frequency of potentially life-threatening events. This may influence daily practice, and the data may be implemented in treatment guidelines or serve as the basis for planning further randomized controlled trials. Considering the critical health of these patients, they will particularly benefit from evidence-based treatment. Systematic review registration: PROSPERO CRD4201502196

    Galactic and Extragalactic Samples of Supernova Remnants: How They Are Identified and What They Tell Us

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    Supernova remnants (SNRs) arise from the interaction between the ejecta of a supernova (SN) explosion and the surrounding circumstellar and interstellar medium. Some SNRs, mostly nearby SNRs, can be studied in great detail. However, to understand SNRs as a whole, large samples of SNRs must be assembled and studied. Here, we describe the radio, optical, and X-ray techniques which have been used to identify and characterize almost 300 Galactic SNRs and more than 1200 extragalactic SNRs. We then discuss which types of SNRs are being found and which are not. We examine the degree to which the luminosity functions, surface-brightness distributions and multi-wavelength comparisons of the samples can be interpreted to determine the class properties of SNRs and describe efforts to establish the type of SN explosion associated with a SNR. We conclude that in order to better understand the class properties of SNRs, it is more important to study (and obtain additional data on) the SNRs in galaxies with extant samples at multiple wavelength bands than it is to obtain samples of SNRs in other galaxiesComment: Final 2016 draft of a chapter in "Handbook of Supernovae" edited by Athem W. Alsabti and Paul Murdin. Final version available at https://doi.org/10.1007/978-3-319-20794-0_90-

    Epidemiology, Quality and Reporting Characteristics of Systematic Reviews of Traditional Chinese Medicine Interventions Published in Chinese Journals

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    Systematic reviews (SRs) of TCM have become increasingly popular in China and have been published in large numbers. This review provides the first examination of epidemiological characteristics of these SRs as well as compliance with the PRISMA and AMSTAR guidelines.To examine epidemiological and reporting characteristics as well as methodological quality of SRs of TCM published in Chinese journals.Four Chinese databases were searched (CBM, CSJD, CJFD and Wanfang Database) for SRs of TCM, from inception through Dec 2009. Data were extracted into Excel spreadsheets. The PRISMA and AMSTAR checklists were used to assess reporting characteristics and methodological quality, respectively.A total of 369 SRs were identified, most (97.6%) of which used the terms systematic review or meta-analysis in the title. None of the reviews had been updated. Half (49.8%) were written by clinicians and nearly half (47.7%) were reported in specialty journals. The impact factors of 45.8% of the journals published in were zero. The most commonly treated conditions were diseases of the circulatory and digestive disease. Funding sources were not reported for any reviews. Most (68.8%) reported information about quality assessment, while less than half (43.6%) reported assessing for publication bias. Statistical mistakes appeared in one-third (29.3%) of reviews and most (91.9%) did not report on conflict of interest.While many SRs of TCM interventions have been published in Chinese journals, the quality of these reviews is troubling. As a potential key source of information for clinicians and researchers, not only were many of these reviews incomplete, some contained mistakes or were misleading. Focusing on improving the quality of SRs of TCM, rather than continuing to publish them in great quantity, is urgently needed in order to increase the value of these studies

    Radio emission from Supernova Remnants

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    The explosion of a supernova releases almost instantaneously about 10^51 ergs of mechanic energy, changing irreversibly the physical and chemical properties of large regions in the galaxies. The stellar ejecta, the nebula resulting from the powerful shock waves, and sometimes a compact stellar remnant, constitute a supernova remnant (SNR). They can radiate their energy across the whole electromagnetic spectrum, but the great majority are radio sources. Almost 70 years after the first detection of radio emission coming from a SNR, great progress has been achieved in the comprehension of their physical characteristics and evolution. We review the present knowledge of different aspects of radio remnants, focusing on sources of the Milky Way and the Magellanic Clouds, where the SNRs can be spatially resolved. We present a brief overview of theoretical background, analyze morphology and polarization properties, and review and critical discuss different methods applied to determine the radio spectrum and distances. The consequences of the interaction between the SNR shocks and the surrounding medium are examined, including the question of whether SNRs can trigger the formation of new stars. Cases of multispectral comparison are presented. A section is devoted to reviewing recent results of radio SNRs in the Magellanic Clouds, with particular emphasis on the radio properties of SN 1987A, an ideal laboratory to investigate dynamical evolution of an SNR in near real time. The review concludes with a summary of issues on radio SNRs that deserve further study, and analyzing the prospects for future research with the latest generation radio telescopes.Comment: Revised version. 48 pages, 15 figure

    The prevention of anaphylactoid reactions to iodinated radiological contrast media: a systematic review

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    BACKGROUND: Anaphylactoid reactions to iodinated contrast media are relatively common and potentially life threatening. Opinion is divided as to the utility of medications for preventing these reactions. We performed a systematic review to assess regimes for the prevention of anaphylactoid reactions to iodinated contrast media. METHODS: Searches for studies were conducted in the Medline, EMBASE, CINAHL and CENTRAL databases. Bibliographies of included studies and review articles were examined and experts were contacted. Randomised clinical trials that examined agents given prior to iodinated contrast material for the prevention of anaphylactoid reactions were included in the review. The validity of the included studies was examined using a component approach. RESULTS: Six studies met the inclusion criteria, but only one of these fulfilled all of the validity criteria. There were four studies that examined the use of H1 antihistamines, each was used to prevent anaphylactoid reactions to ionic contrast. The random effects pooled relative risk demonstrated a significant reduction in the overall rate of anaphylactoid reactions (RR = 0.4, 95% CI 0.18-0.9, p = 0.027). There were insufficient studies to produce a pooled statistic for the use of corticosteroids, however regimes of steroids (methylprednisolone 32 mg) given at least six hours and again two hours prior to the administration of contrast suggested a reduction in the incidence of anaphylactoid reactions. CONCLUSION: In conclusion, there are few high quality randomised clinical trials that have addressed the question of the optimal methods to prevent allergic type reactions to iodinated radiological contrast media. Allowing for these limitations, the results suggest that H1 antihistamines given immediately prior to the administration of ionic contrast may be useful in preventing reactions to ionic contrast and are suggestive of a protective effect of corticosteroids when given in two doses at least six hours prior and again two hours prior to the administration of contrast, both ionic and non-ionic. These agents should be considered for use in patients who are at high risk of an anaphylactoid reaction to contrast media and for who prophylactic therapy is considered necessary. Further research is needed before definitive recommendations can be made
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