392,350 papers found

Thank you for the constructive feedback on our recent meta-analysis on peripheral biomarkers in anorexia nervosa (AN) [...].

On analyzing the important article published in this journal "The efficacy of immediate lymphatic reconstruction after axillary lymph node dissection - A meta-analysis", I would like to make some comments that are important in the management of these patients, in particular, the best time to indicate the procedure.

Epidemiologic research often involves meta-analyses of proportions. Conventional two-step methods first transform each study's proportion and subsequently perform a meta-analysis on the transformed scale. They suffer from several important limitations: the log and logit transformations impractically treat within-study…

We describe a meta-analytic scatterplot that indicates precision of points for two variables paired within studies; this is equivalent in form to a 'cross-hairs' plot used to portray specificity and sensitivity in diagnostic testing. At the user's discretion, the plot also displays boxplots for each of the X and Y vari…

Statistical synthesis of research findings via meta-analysis is widely used to assess the relative effectiveness of competing interventions. A series of three papers aimed at familiarising mental health scientists with the key statistical concepts and problems in meta-analysis was recently published in this journal. On…

We propose 2 related models for the meta-analysis of diagnostic tests. Both models are based on the bivariate normal distribution for transformed sensitivities and false-positive rates. Instead of using the logit as a transformation for these proportions, we employ the tα family of transformations that contains t…

In this paper, we address the critical assessment of Ramsey et al. of our method for learning partially directed graphs from meta-analysis imaging data (Neumann et al., 2010). We argue that our method provides valid and interpretable results when applied to data representing a single experimental paradigm. Simulations…

The importance of evidence-based diagnostic practice has been increasingly recognised over the past decade. Meta-analyses are used to summarise and assess the literature and are therefore particularly important tools in radiological research. Diagnostic radiology is driven by emerging technologies that are increasingly…

Meta-analysis on surgical infections may be a useful tool that can provide more accurate outcome estimates than other conventional types of studies. Published meta-analyses in surgical infections tend to focus mainly on the use of antimicrobial prophylaxis and on the comparison of different procedures or techniques for…

A recent meta-analysis of randomized clinical trials reported by Bongartz and coworkers raised concerns about an increased rate of malignancy and serious infection in rheumatoid arthritis patients treated with anti-tumour necrosis factor monoclonal antibodies. This commentary discusses some of the methodological issues…

Assay sensitivity has been proposed as a criterion for including psychiatric clinical outcome studies in meta-analyses. The authors assess the performance of assay sensitivity as a method for determining study appropriateness for meta-analysis by calculating expected standard drug vs placebo effect sizes for various co…

Systematic reviews use explicit and reproducible criteria to assemble, appraise, and combine articles with a minimum of bias. Meta-analysis is a form of systematic review that uses statistical techniques to derive quantitative estimates of the magnitude of treatment effects and their associated precision. Valid meta-an…

The efficacy of the Hedges and colleagues, Rosenthal-Rubin, and Hunter-Schmidt methods for combining correlation coefficients was tested for cases in which population effect sizes were both fixed and variable. After a brief tutorial on these meta-analytic methods, the author presents two Monte Carlo simulations that co…

Meta-analyses can provide clinicians with the evidence-based information necessary to effect change in patient care delivery. Meta-analysis, the application of statistical techniques to condense data from a group of individual studies, is the most sophisticated summary of research evidence. An example meta-analysis stu…

The objective of the present article is to review the biases in meta-analysis. This procedure can be included within observational studies, and its biases follow the same classification: selection, information and confounding bias. Selection bias can always be present because of the impossibility of enumerating the ref…

Meta-analysis, though increasingly popular in clinical medicine, has not found acceptance in anatomic pathology. This paper argues that, in combination with a systematic review of the literature, meta-analysis may be usefully applied to pathological research and two examples drawn from gynaecological pathology (the val…

Large scale placebo-controlled trials with clinical end-points are not possible when other compounds with proven efficacy are already available. Hence, the question arises whether the available experience from placebo-controlled phase III trials can be analysed jointly to assess whether an effect on clinical end-points…