392,164 papers found

The search for fast and reliable methods allowing for extraction of biomarker genes, e.g. responsible for a plant resistance to a certain pathogen, is one of the most important and highly exploited data mining problem in bioinformatics. Here we describe a simple and efficient method suitable for combining results from…

Induction for postdates in low-risk pregnancy was adopted with the intent to prevent post-term antepartum stillbirth, the most common cause of perinatal death, based on evidence derived in English language RCT meta-analysis. Systematic English language meta-analysis of RCT studies of induction for postdates in low-risk…

BACKGROUND: The rank correlation test introduced by Begg and Mazumdar is extensively used in meta-analysis to test for publication bias in clinical and epidemiological studies. It is based on correlating the standardized treatment effect with the variance of the treatment effect using Kendall's tau as the measure of as…

Reporting and publication bias is a well-known problem in meta-analysis and healthcare research. In 2002 we conducted a meta-analysis on the effects of erythropoiesis-stimulating agents (ESAs) on overall survival in cancer patients, which suggested some evidence for improved survival in patients receiving ESAs compared…

OBJECTIVES: The aim of this study was to propose a statistical model that takes into account clinical data on earlier versions when evaluating the latest version of an implantable medical device (IMD). METHODS: We compared the performances of a bayesian three-level hierarchical meta-analysis model with those of a baye…

We describe methods for meta-analysis of randomised trials where a continuous outcome is of interest, such as blood pressure, recorded at both baseline (pre treatment) and follow-up (post treatment). We used four examples for illustration, covering situations with and without individual participant data (IPD) and with…

Genome-Wide Association Studies (GWAS) frequently incorporate meta-analysis within their framework. However, conditional analysis of individual-level data, which is an established approach for fine mapping of causal sites, is often precluded where only group-level summary data are available for analysis. Here, we prese…

SUMMARY: With the rapid advances and prevalence of high-throughput genomic technologies, integrating information of multiple relevant genomic studies has brought new challenges. Microarray meta-analysis has become a frequently used tool in biomedical research. Little effort, however, has been made to develop a systemat…

OBJECTIVES: Evidence-based medicine (EBM) relies on systematic review (SR), meta-analysis (MA) and randomized controlled trials (RCTs). These EBM tools are more commonly used in clinical medicine than in laboratory medicine. The extent of their use in cytopathology is not clear. The purpose of this study was to investi…

A significant proportion of the outcomes reported in trials assessing venous thromboembolism (VTE) prophylaxis in medical patients are related to asymptomatic events found on routine imaging studies. The implications of these events are controversial. Moreover, such trials did not always reflect the patient mix in toda…

BACKGROUND: Detecting candidate markers in transcriptomic studies often encounters difficulties in complex diseases, particularly when overall signals are weak and sample size is small. Covariates including demographic, clinical and technical variables are often confounded with the underlying disease effects, which fur…

Two methods for point and interval estimation of relative risk for log-linear exposure-response relations in meta-analyses of published ordinal categorical exposure-response data have been proposed. The authors compared the results of a meta-analysis of published data using each of the 2 methods with the results that w…

Modern management of blunt aortic injury (BAI) is based on evidence from mostly well-conducted meta-analyses as surrogates for prospective randomized controlled trials. There are several obvious pros and cons to this strategy. The advantages rest on the fact that it is unlikely that a prospective randomized trial compa…

OBJECTIVE: The aim of the study is to summarize the effect of intensive-dose continuous renal replacement therapy (CRRT) on the mortality and other clinical outcomes. METHODS: A systematic search for randomized, controlled trials (RCTs) was performed. We estimated pooled relative ratios and 95% confidence intervals us…

BACKGROUND: Lateral ventricular enlargement is one of the most consistent findings in patients with schizophrenia; however whether progressive ventricular dilation occurs during the course of the illness has been controversial. To clarify this we conducted a meta-analysis of longitudinal studies measuring the lateral v…

A systematic review of studies that focused on the executive functions of problem solving, planning, organising and multitasking by adults with traumatic brain injury (TBI) was performed through 2004. Qualitative and quantitative methods were used to evaluate the 15 studies that met inclusion criteria. Demographic vari…

BACKGROUND: Although prognostic biomarkers specific for particular cancers have been discovered, microarray analysis of gene expression profiles, supported by integrative analysis algorithms, helps to identify common factors in molecular oncology. Similarities of Ordered Gene Lists (SOGL) is a recently proposed approac…

In 2002, serious criticism was raised about the use of standard statistical software (Splus, SAS, Stata) to fit Generalized Additive Models (GAM) to epidemiological time series data. This criticism concerns convergence problems of the backfitting algorithm and inappropriate use of a linear approximation in estimating s…

One of the most popular experimental paradigms for functional neuroimaging studies of working memory has been the n-back task, in which subjects are asked to monitor the identity or location of a series of verbal or nonverbal stimuli and to indicate when the currently presented stimulus is the same as the one presented…

OBJECTIVE: A major problem for meta-analysis of multiple outcomes is the unavailability of some estimates from published and unpublished studies. Dissemination bias, in how and what outcomes are reported or published, may be causing this incompleteness. This article illustrates these problems and presents possible sens…