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Thyroid hormones for acute kidney injury
No full textBackgroundAcute kidney injury (AKI), which is common in hospitalised patients, is associated with significant morbidity and mortality. Despite recent advances in treatment, AKI outcomes have not changed substantially during the past four decades, and incidence is increasing. There is an urgent need to explore novel therapeutic agents and revisit some older drugs to review their roles in the management of AKI. Although thyroid hormone therapy has shown promise in experimental animal studies, clinical efficacy and safety have not been systematically assessed for the management of people with AKI.ObjectivesTo evaluate the benefits and harms of thyroid hormones for the treatment of hospitalised adults with AKI of any aetiology.Search methodsWe searched the Cochrane Renal Group's Specialised Register, CENTRAL, MEDLINE, and EMBASE. We also checked the reference lists of retrieved studies and articles.Date of search: November 2012Selection criteriaRandomised controlled trials (RCTs) and quasi-RCTs (in which allocation to treatment was obtained by alternation, use of alternate medical records, date of birth or other predictable methods) that compared any dose or form of thyroid hormone therapy alone or in combination with other agents compared with placebo or supplemental treatment (such as furosemide, dopamine, or atrial natriuretic peptide) in adult AKI patients.Data collection and analysisTwo authors independently assessed study quality and extracted data. The quality of included studies was assessed using the Cochrane Collaboration's risk of bias assessment tool. For dichotomous outcomes (death, need for renal replacement therapy (RRT), progression to end-stage kidney disease (ESKD)), we planned to express results as risk ratios (RR) with 95% confidence intervals (CI). Where continuous scales of measurement were used to assess the effects of treatment (length of hospital stay, durations of AKI and RRT), we planned to use the mean difference (MD).Main resultsTwo studies, enrolling 97 participants, met our inclusion criteria. The studies differed significantly in terms of study populations, natural history of AKI (multifactorial AKI in patients with native kidneys versus delayed graft function associated with acute tubular necrosis in transplant recipients), and study interventions; hence, data were not meta-analysed. One study reported a significant increase in the risk of all-cause mortality associated with thyroid hormone interventions compared with placebo (59 participants, RR 3.32, 95% CI 1.21 to 9.12); no deaths were reported in the other study. Both studies reported no significant difference in the need for RRT associated with thyroid hormone therapy when compared to placebo. Neither study reported incidence of progression to ESKD. There was a significantly longer duration of AKI (MD 2.00 days, 95% CI 0.18 to 3.82) and RRT (5.00 days, 95% CI 2.05 to 7.95) associated with thyroid hormone therapy compared with placebo in one study; no differences in durations of AKI (MD 2.00 days, 95% CI -3.53 to 7.53) and RRT (MD 2.00 days, 95% CI -2.36 to 6.36) were noted in the other study. One study reported similar lengths of stay in the intensive care unit and hospital in both intervention and control arms (MD -0.20 days, 95% CI -8.17 to 7.77); the other did not report this outcome. No adverse events were noted to be associated with thyroid hormone therapy in either study. Adequate data were not available to assess changes in kidney function or numbers of RRT sessions. Both included studies were small and methodological quality was suboptimal.Authors' conclusionsWe found a paucity of large, high quality studies to inform analysis of thyroid hormone interventions for the treatment of people with AKI. Current evidence suggested that thyroid hormone therapy may be associated with worse outcomes for patients with established AKI; therefore, its use for these patients should be avoided. The role of thyroid hormone therapy in preventing AKI has not been adequately investigated and may be considered in future clinical studies
Aldosterone antagonists for preventing the progression of chronic kidney disease
No full textBackgroundTreatment with angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) is increasingly used to reduce proteinuria and retard the progression of chronic kidney disease (CKD). However, resolution of proteinuria may be incomplete with these therapies and the addition of an aldosterone antagonist may be added to further prevent progression of CKD. This is an update of a review first published in 2009.ObjectivesTo evaluate the effect of aldosterone antagonists (both selective (eplerenone) and non-selective (spironolactone)) alone or in combination with ACEi or ARB in adults who have CKD with proteinuria (nephrotic and non-nephrotic range) on: patient-centred endpoints including major cardiovascular events, hospitalisation and all-cause mortality; kidney function (proteinuria, glomerular filtration rate (GFR), serum creatinine, and need for renal replacement therapy; and adverse events (including gynaecomastia and hyperkalaemia).Search methodsFor this update, we searched the Cochrane Renal Group's Specialised Register to 30 January 2013 using search terms relevant to this review.Selection criteriaWe included randomised controlled trials (RCTs) and quasi-RCTs that compared aldosterone antagonists alone or in combination with ACEi or ARB (or both) with other anti-hypertensive strategies or placebo.Data collection and analysisTwo authors independently assessed study quality and extracted data. Data were summarised using random effects meta-analysis. We tested for heterogeneity in estimated treatment effects using the Cochran Q test and I-2 statistic. We expressed summary treatment estimates as a risk ratio (RR) for dichotomous outcomes together with their 95% confidence intervals (CI) and mean difference (MD) for continuous outcomes, or standardised mean difference (SMD) when different scales were used.Main resultsWe identified 27 studies (1549 participants) that were eligible for inclusion. These studies provided no data relating to aldosterone antagonists in addition to ACEi or ARB (or both) on patient-level outcomes including major cardiovascular events and mortality and progression to end-stage kidney disease (ESKD) requiring dialysis or transplantation.Compared with ACEi or ARB (or both), non-selective aldosterone antagonists (spironolactone) combined with ACEi or ARB (or both) significantly reduced 24-hour protein excretion (11 studies, 596 participants): SMD -0.61, 95% CI -1.08 to -0.13). There was a significant reduction in both systolic and diastolic blood pressure (BP) at the end of treatment with additional non-selective aldosterone antagonist therapy (systolic BP (10 studies, 556 participants): MD -3.44 mm Hg, 95% CI -5.05 to -1.83) (diastolic BP (9 studies, 520 participants): MD -1.73 mm Hg, 95% CI -2.83 to -0.62).However, we found that aldosterone antagonist treatment had imprecise effects at the end of treatment on GFR (9 studies, 528 participants; MD -2.55 mL/min/1.73 m(2), 95% CI -5.67 to 0.51), doubled the risk of hyperkalaemia (11 studies, 632 patients): RR 2.00, 95% CI 1.25 to 3.20; number needed to treat for an additional harmful outcome (NNTH): 7.2, 95% CI 3.4 to) and increased the risk of gynaecomastia compared to ACEi or ARB (or both) (4 studies, 281 patients): RR 5.14, 95% CI 1.14 to 23.23; NNTH: 14.1, 95% CI 8.7 to 37.3).Most studies enrolled few patients (range 12 to 268) and were powered to observe differences in surrogate end points rather than patient-focused outcomes. Nine studies had a cross-over design and the majority of studies did not adequately report study methods to assess methods and study quality.Authors' conclusionsAldosterone antagonists reduced proteinuria and blood pressure in adults who had mild to moderate CKD and were treated with ACEi or ARB (or both), but increase hyperkalaemia and gynaecomastia. Whether adding aldosterone antagonists to ACEi or ARB (or both) reduced the risk of major cardiovascular events or ESKD in this population is unknown
Darbepoetin for the anaemia of chronic kidney disease
No full textBackgroundErythropoiesis-stimulating agents are used to treat anaemia in people with chronic kidney disease (CKD). Several agents are available including epoetin alfa or beta as well as agents with a longer duration of action, darbepoetin alfa and methoxy polyethylene glycolepoetin beta.ObjectivesTo assess the benefits and harms of darbepoetin alfa to treat anaemia in adults and children with CKD (stages 3 to 5, 5D, and kidney transplant recipients).Search methodsWe searched the Cochrane Renal Group's Specialised Register (to 13 January 2014) through contact with the Trials' Search Co-ordinator using search terms relevant to this review. Studies contained in the Specialised Register are identified through search strategies specifically designed for CENTRAL, MEDLINE and EMBASE.Selection criteriaWe included randomised controlled trials of any darbepoetin alfa treatment of at least three months duration in adults or children with CKD (any stage).Data collection and analysisData were extracted by two independent investigators. Patient-centred outcomes (need for blood transfusion, iron therapy, progression of kidney disease, total and cardiovascular mortality, cardiovascular events, cancer, hypertension, seizures, and health-related quality of life) and other outcomes (haemoglobin levels) were assessed using random effects meta-analysis. We calculated risk ratios for dichotomous outcomes and mean differences for continuous outcomes, both with 95% confidence intervals.Main resultsWe identified 32 studies comprising 9414 participants; 21 studies in 8328 participants could be included in our meta-analyses. One study (4038 participants) compared darbepoetin alfa to placebo, 16 studies (2955 participants) compared darbepoetin alfa to epoetin alfa or beta, four studies (1198 participants) compared darbepoetin alfa to methoxy polyethylene glycol-epoetin beta, three studies (420 participants) compared more frequent with less frequent darbepoetin alfa administration and four studies (303 participants) compared intravenous with subcutaneous darbepoetin alfa administration.In a single large study, darbepoetin alfa reduced the need for blood transfusion and iron therapy compared with placebo in adults with CKD stage 3 to 5, but had little or no effect on survival, increased risks of hypertension, and had uncertain effects on quality of life. Data comparing darbepoetin alfa with epoetin alfa or beta or methoxy polyethylene glycol-epoetin beta were sparse and inconclusive. Comparisons of differing dosing schedules and routes of administration were compared in small numbers of participants and studies. Evidence for treatment effects of darbepoetin alfa were particularly limited for children with CKD, adults with CKD stage 5D, and recipients of a kidney transplant.Studies included in this review were generally at high or unclear risk of bias for all items (random sequence generation, allocation concealment, incomplete outcome data, blinding of participants and personnel, blinding of outcome assessment, selective outcome reporting, intention to treat analysis and other sources of bias). One large study comparing darbepoetin alfa with placebo was at low risk of bias for most items assessed.Authors' conclusionsData suggest that darbepoetin alfa effectively reduces need for blood transfusions in adults with CKD stage 3 to 5, but has little or no effect on mortality or quality of life. The effects of darbepoetin alfa in adults with CKD stage 5D and kidney transplant recipients and children with CKD remain uncertain as do the relative benefits and harms of darbepoetin alfa compared with other ESAs (epoetin alfa or beta and methoxy polyethylene glycol-epoetin beta)
HMG CoA reductase inhibitors (statins) for people with chronic kidney disease not requiring dialysis
No full textBackgroundCardiovascular disease (CVD) is the most frequent cause of death in people with early stages of chronic kidney disease (CKD), for whom the absolute risk of cardiovascular events is similar to people who have existing coronary artery disease. This is an update of a review published in 2009, and includes evidence from 27 new studies (25,068 participants) in addition to the 26 studies (20,324 participants) assessed previously; and excludes three previously included studies (107 participants). This updated review includes 50 studies (45,285 participants); of these 38 (37,274 participants) were meta-analysed.ObjectivesTo evaluate the benefits (such as reductions in all-cause and cardiovascular mortality, major cardiovascular events, MI and stroke; and slow progression of CKD to end-stage kidney disease (ESKD)) and harms (muscle and liver dysfunction, withdrawal, and cancer) of statins compared with placebo, no treatment, standard care or another statin in adults with CKD who were not on dialysis.Search methodsWe searched the Cochrane Renal Group's Specialised Register to 5 June 2012 through contact with the Trials' Search Co-ordinator using search terms relevant to this review.Selection criteriaRandomised controlled trials (RCTs) and quasi-RCTs that compared the effects of statins with placebo, no treatment, standard care, or other statins, on mortality, cardiovascular events, kidney function, toxicity, and lipid levels in adults with CKD not on dialysis were the focus of our literature searches.Data collection and analysisTwo or more authors independently extracted data and assessed study risk of bias. Treatment effects were expressed as mean difference (MD) for continuous outcomes (lipids, creatinine clearance and proteinuria) and risk ratio (RR) for dichotomous outcomes (major cardiovascular events, all-cause mortality, cardiovascular mortality, fatal or non-fatal myocardial infarction (MI), fatal or non-fatal stroke, ESKD, elevated liver enzymes, rhabdomyolysis, cancer and withdrawal rates) with 95% confidence intervals (CI).Main resultsWe included 50 studies (45,285 participants): 47 studies (39,820 participants) compared statins with placebo or no treatment and three studies (5547 participants) compared two different statin regimens in adults with CKD who were not yet on dialysis. We were able to meta-analyse 38 studies (37,274 participants).The risk of bias in the included studies was high. Seven studies comparing statins with placebo or no treatment had lower risk of bias overall; and were conducted according to published protocols, outcomes were adjudicated by a committee, specified outcomes were reported, and analyses were conducted using intention-to-treat methods. In placebo or no treatment controlled studies, adverse events were reported in 32 studies (68%) and systematically evaluated in 16 studies (34%).Compared with placebo, statin therapy consistently prevented major cardiovascular events (13 studies, 36,033 participants; RR 0.72, 95% CI 0.66 to 0.79), all-cause mortality (10 studies, 28,276 participants; RR 0.79, 95% CI 0.69 to 0.91), cardiovascular death (7 studies, 19,059 participants; RR 0.77, 95% CI 0.69 to 0.87) and MI (8 studies, 9018 participants; RR 0.55, 95% CI 0.42 to 0.72). Statins had uncertain effects on stroke (5 studies, 8658 participants; RR 0.62, 95% CI 0.35 to 1.12).Potential harms from statin therapy were limited by lack of systematic reporting and were uncertain in analyses that had few events: elevated creatine kinase (7 studies, 4514 participants; RR 0.84, 95% CI 0.20 to 3.48), liver function abnormalities (7 studies, RR 0.76, 95% CI 0.39 to 1.50), withdrawal due to adverse events (13 studies, 4219 participants; RR 1.16, 95% CI 0.84 to 1.60), and cancer (2 studies, 5581 participants; RR 1.03, 95% CI 0.82 to 130).Statins had uncertain effects on progression of CKD. Data for relative effects of intensive cholesterol lowering in people with early stages of kidney disease were sparse. Statins clearly reduced risks of death, major cardiovascular events, and MI in people with CKD who did not have CVD at baseline (primary prevention).Authors' conclusionsStatins consistently lower death and major cardiovascular events by 20% in people with CKD not requiring dialysis. Statin-related effects on stroke and kidney function were found to be uncertain and adverse effects of treatment are incompletely understood. Statins have an important role in primary prevention of cardiovascular events and mortality in people who have CKD
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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