1,720,971 research outputs found
Comparing the performance of the EQ-5D and SF-6D when measuring the benefits of alleviating knee pain
No full textObective: to assess the practicality, validity and responsiveness of using each of two utility measures (the EQ-5D and SF-6D) to measure the benefits of alleviating knee pain.Methods: participants in a randomised controlled trial, which was designed to compare four different interventions for people with self-reported knee pain, were asked to complete the EQ-5D, SF-6D, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at both pre- and post-intervention. For both utility measures, we assessed their practicality (completion rate), construct validity (ability to discriminate between baseline WOMAC severity levels), and responsiveness (ability to discriminate between three groups: those whose total WOMAC score, i) did not improve, ii) improved by <20%, and iii) improved by > or = 20%).Results: the EQ-5D was completed by 97.7% of the 389 participants, compared to 93.3% for the SF-6D. Both the EQ-5D and SF-6D were able to discriminate between participants with different levels of WOMAC severity (p < 0.001). The mean EQ-5D change was -0.036 for group i), 0.091 for group ii), and 0.127 for group iii), compared to 0.021, 0.023 and 0.053 on the SF-6D. These change scores were significantly different according to the EQ-5D (p < 0.001), but not the SF-6D.Conclusion: the EQ-5D and SF-6D had largely comparable practicality and construct validity. However, in contrast to the EQ-5D, the SF-6D could not discriminate between those who improved post-intervention, and those who did not. This suggests that it is more appropriate to use the EQ-5D in future cost-effectiveness analyses of interventions which are designed to alleviate knee pain.</p
Do estimates of cost-utility based on the EQ-5D differ from those based on the mapping of utility scores?
No full textBackground: mapping has been used to convert scores from condition-specific measures into utility scores, and to produce estimates of cost-effectiveness. We sought to compare the QALY gains, and incremental cost per QALY estimates, predicted on the basis of mapping to those based on actual EQ-5D scores.Methods: in order to compare 4 different interventions 389 individuals were asked to complete both the EQ-5D and the Western Ontartio and McMaster Universities Osteoarthritis Index (WOMAC) at baseline, 6, 12, and 24 months post-intervention. Using baseline data various mapping models were developed, where WOMAC scores were used to predict the EQ-5D scores. The performance of these models was tested by predicting the EQ-5D post-intervention scores. The preferred model (that with the lowest mean absolute error (MAE)) was used to predict the EQ-5D scores, at all time points, for individuals who had complete WOMAC and EQ-5D data. The mean QALY gain associated with each intervention was calculated, using both actual and predicted EQ-5D scores. These QALY gains, along with previously estimated changes in cost, were also used to estimate the actual and predicted incremental cost per QALY associated with each of the four interventions.Results: the EQ-5D and the WOMAC were completed at baseline by 348 individuals, and at all time points by 259 individuals. The MAE in the preferred model was 0.129, and the mean QALY gains for each of the four interventions was predicted to be 0.006, 0.058, 0.058, and 0.136 respectively, compared to the actual mean QALY gains of 0.087, 0.081, 0.120, and 0.149. The most effective intervention was estimated to be associated with an incremental cost per QALY of pound6,068, according to our preferred model, compared to pound13,154 when actual data was used.Conclusion: we found that actual QALY gains, and incremental cost per QALY estimates, differed from those predicted on the basis of mapping. This suggests that though mapping may be of value in predicting the cost-effectiveness of interventions which have not been evaluated using a utility measure, future studies should be encouraged to include a method of actual utility measurement.Trial registration: current Controlled Trials ISRCTN93206785.</p
An assessment of the discriminative ability of the EQ-5Dindex, SF-6D, and EQ VAS, using sociodemographic factors and clinical conditions
No full textObjective: to assess whether three health-related quality-of-life (HRQL) measures (the EQ-5Dindex, SF-6D, and EQ VAS) can discriminate between the HRQL of different groups of individuals.Methods: in one UK general practice a cross-sectional survey requested information on six sociodemographic factors, 10 clinical conditions, and the three HRQL measures. Regression analyses were used to assess whether there was a significant difference in HRQL between groups with different sociodemographic factors and those with and without clinical conditions.Results: one thousand eight hundred and sixty-five questionnaires were returned. There was a significant difference between the HRQL of the majority of different groups according to each HRQL measure. However, not all of the measures could discriminate between groups of different ethnicity, gender, or smoking status, or those with and without asthma, stroke, cancer or diabetes.Conclusion: the HRQL of the majority of different groups could be discriminated between by the EQ-5Dindex, SF-6D, and EQ VAS.</p
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
Comparing cost-utility estimates: does the choice of EQ-5D or SF-6D matter?
No full textBACKGROUND: A number of different measures can be used within cost-utility analyses, we compared results according to both the EQ-5D and SF-6D. METHODS: A randomized trial was conducted to compare 4 options for people with knee pain. Over the 2 year trial period, the change in cost to health-service was estimated, and both the EQ-5D and SF-6D were used to estimate the change in quality-adjusted life years (QALYs). Using a complete case analysis, the cost-utility (incremental cost-effectiveness ratio [ICER]) of each option, according to both the EQ-5D and SF-6D, was calculated and assessed in relation to the cost-effectiveness threshold of pound20,000 per QALY. RESULTS: Of the 389 participants, 247 had complete cost, EQ-5D and SF-6D data. According to the EQ-5D, option 1 had an estimated ICER of pound10,815 (compared with option 4), option 2 was dominated by option 1, and option 3 was subject to extended dominance. Conversely, according to the SF-6D, option 3 had an ICER of pound9999 (compared with option 4), option 2 had an ICER of pound36,883 (compared with option 3), and option 1 was subject to extended dominance. CONCLUSION: The EQ-5D and SF-6D estimated that different options (1 and 3, respectively) were cost-effective at the pound20,000 per QALY threshold, demonstrating that the choice of measure does matter
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
- …
