1,721,042 research outputs found
The clinical and cost-effectiveness of peginterferon alfa and ribavirin for the treatment of chronic hepatitis C in children and young people
No full textTime to full publication of studies of anti-cancer medicines for breast cancer, and the potential for publication bias: a short systematic review
No full textObjectives: To identify the expected delay between publication of conference abstracts and full publication of results from trials of new anti-cancer agents for breast cancer and to identify whether there are any apparent biases in publication and reporting.Data sources: Major electronic databases were searched to identify randomised controlled trials (RCTs) of the selected interventions for the treatment of breast cancer.Review methods: A systematic review was conducted according to standard methods. Data were extracted from the included studies using a predesigned and piloted data extraction template.Results: Six anti-cancer treatments for breast cancer were included in the review: docetaxel, paclitaxel, trastuzumab, gemcitabine, lapatinib and bevacizumab. The literature searches generated 1556 references, from which 71 publications were retrieved and screened for inclusion. Screening identified 41 publications of 18 RCTs with at least one arm of treatment meeting the inclusion criteria for the review. Of the 18 included RCTs, only four publications (from three RCTs) reported the same outcomes in both an abstract and a full publication. Time between the abstract and full publication was 5 months in two cases, 7 months in one case and 19 months in one case (overall mean delay = 9 months). Eleven trials were identified that have not currently published in a full publication the data presented in an abstract or conference proceeding. The duration between publication of the abstracts and the end of August 2007 varied from 3 months to 38 months (mean delay 16.5 months). The longest delays in publication were for trials investigating gemcitabine (38 months) or bevacizumab (33 months). Observational analysis of the published and unpublished trials did not indicate any particular biases in terms of whether positive results were more likely to be fully published than non-significant ones.Conclusions: It was surprising that only three of the 18 relevant RCTs had one or more full papers that reported the same outcome measures (and stage of analysis) as an earlier conference abstract. However, a limitation of this review is the small number of studies included. With a larger sample size than that in the present report, investigation into the effect of publication delay on decision-making might be feasible. Future research should include extension of this work to other anticancer drugs and investigation into the reasons for lengthy delays to full publication noted for some trials
Peginterferon alfa and ribavirin for chronic hepatitis C in patients eligible for shortened treatment, re-treatment or in HCV/HIV co-infection: a systematic review and economic evaluation
Full text linkThe aim of this health technology assessment is to assess the clinical-effectiveness and cost-effectiveness of peginterferon alfa and ribavirin for the treatment of chronic hepatitis C. Interferon alfa (pegylated and non-pegylated) and ribavirin for the treatment of moderate to severe hepatitis C was appraised by NICE in 2004 (TA751) and an appraisal specifically for mild hepatitis C was carried out in 2006 (TA1062). Both appraisals were based on independent assessment reports conducted by SHTAC.3,4Since NICE's clinical guidance was published, there have been extensions to the licences for peginterferon alfa-2a and -2b. This health technology assessment is a part-review of the current NICE guidance and will be restricted to the patient subgroups that are affected by the licence extensions for the peginterferons. This includes people who have been previously treated with peginterferon alfa and ribavirin in combination and who either did not respond or who responded but relapsed, people who meet the licensed criteria for receiving shortened courses of combination therapy and people with HCV/HIV co-infectionThe HTA Programme commissioned this technology assessment report on behalf of the National Institute for Health and Clinical Excellence
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
Telbivudine for the treatment of chronic hepatitis B infection
No full textThis paper presents a summary of the evidence review group (ERG) report into the clinical effectiveness and cost-effectiveness of telbivudine for the treatment of chronic hepatitis B (CHB) in adults based upon a review of the manufacturer's submission to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The submission's evidence came from one randomised controlled trial (RCT) (GLOBE) of reasonable methodological quality comparing telbivudine with lamivudine. One other RCT that appeared to meet the inclusion criteria was excluded from the submission. For the primary outcome of therapeutic response telbivudine was statistically superior to lamivudine at weeks 52 and 104 for hepatitis B e antigen (HBeAg)-positive patients, and at week 104 for HBeAg-negative patients. There were statistically significant differences in favour of telbivudine for some secondary outcomes at 2 years including hepatitis B virus (HBV) DNA reduction, HBV DNA non-detectability and alanine aminotransferase normalisation though not for HBeAg-positive patients. In HBeAg-positive patients there was no significant difference between treatment groups for HBeAg loss or seroconversion at any time point. The incidence of adverse events was similar between treatments. Two RCTs comparing entecavir with lamivudine were included in the indirect comparison; however, this was poorly conducted and the results should be treated with caution. The manufacturer developed two economic models to determine the cost-effectiveness of telbivudine. Evidence on the efficacy of telbivudine and lamivudine was taken from the GLOBE trial; efficacy of adefovir was based on assumption. There was a lack of critical assessment and assurance of the quality of the data used to populate the models. The manufacturer concluded that telbivudine is a cost-effective option compared with lamivudine using evidence from the viral load model [HBeAg-positive patients/HBeAg-negative patients: mean incremental cost 19,087 pounds/49,003 pounds, mean quality-adjusted life-year (QALY) gain 1.30/4.67, incremental cost-effectiveness ratio (ICER) 14,665 pounds/10,497 pounds per QALY]. Resubmitted results after a request for clarification by the ERG gave less favourable ICERs (HBeAg-positive patients/HBeAg-negative patients: mean incremental cost 23,983 pounds/41,910 pounds, mean QALY gain 1.56/2.07, ICER 15,377 pounds/20,256 pounds per QALY). The manufacturer concluded that telbivudine is a cost-effective option (on its own or followed by adefovir) for patients who have developed resistance to first-line telbivudine treatment; however, the presentation of the results was not ideal. In conclusion, although telbivudine was statistically superior to lamivudine for most antiviral outcomes, the difference was not clinically significant; in addition, the cost-effectiveness evidence for telbivudine presented in the manufacturer's submission was limited. The NICE guidance issued as a result of the STA states that telbivudine is not recommended for the treatment of chronic hepatitis B and that people currently receiving telbivudine should have the option to continue therapy until they and their clinicians consider it appropriate to stop
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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