381,819 papers found

Multiple treatment comparison (MTC) meta-analysis uses both direct (head-to-head) randomized clinical trial (RCT) evidence as well as indirect evidence from RCTs to compare the relative effectiveness of all included interventions. The methodological quality of MTCs may be difficult for clinicians to interpret because t…

For a network meta-analysis, an interlinked network of nodes representing competing treatments is needed. It is often challenging to define the nodes as these typically refer to similar but rarely identical interventions. The objectives of this paper are as follows: (i) to present a series of network meta-analysis mode…

BACKGROUND: Combining the results of studies using highly parallelized measurements of gene expression such as microarrays and RNAseq offer unique challenges in meta analysis. Motivated by a need for a deeper understanding of organ transplant rejection, we combine the data from five separate studies to compare acute re…

Meta-analysis is an important method in the practice of occupational epidemiology, with a legitimate, but limited role to play in causal inference. Meta-analysis provides an assessment of consistency-one of several classic causal criteria-through tests of heterogeneity and an assessment of differences across studies. I…

OBJECTIVE: To compare the results of meta-analysis of nonrandomized comparative studies (NRCSs) of a surgical procedure with that of randomized controlled trials (RCTs), and to assess the effect of design and conduct issues in NRCSs on measured outcomes. STUDY DESIGN AND SETTING: Two meta-analyses of RCTs and NRCSs (2…

OBJECTIVES: In a literature-based meta-analysis for time-to-event data, the hazard ratio in each trial is often estimated from the summary statistics described in the article. Several methods have been proposed: the direct method (Peto method); the indirect method using a p-value by the log-rank test and the number of…

RATIONALE, AIMS AND OBJECTIVES: Repeated measures studies are found in many areas of research, particularly in areas of healthcare. There is currently little information available to inform the method of meta-analysis of repeated measures studies so that the structural dependence of the data is appropriately accommodat…

Motivated by the overwhelming success of genome-wide association studies, droves of researchers are working vigorously to exchange and to combine genetic data to expediently discover genetic risk factors for common human traits. The primary tools that fuel these new efforts are imputation, allowing researchers who have…

Given the policy relevance and growing volume of research measuring individuals' willingness to pay (WTP) for health-related goods and services, meta-analysis provides a potentially rich set of tools for answering key questions about this research area. In particular, when taken as a whole, what does the existing empir…

BACKGROUND: Using data from a published meta-analysis of magnetic resonance imaging of the menisci and cruciate ligaments, the authors varied the overall sensitivity and specificity, the between-studies variance, the within-study sample size, and the number of studies to evaluate the performances of the 3 methods in a…

BACKGROUND: Cluster randomization trials are widely used to test the effect of an intervention when individuals are naturally found in groups such as communities. For several separate studies of a similar intervention, it may be of interest to combine their results using meta-analysis procedures. However, this task req…

MOTIVATION: With the increasing availability of cancer microarray data sets there is a growing need for integrative computational methods that evaluate multiple independent microarray data sets investigating a common theme or disorder. Meta-analysis techniques are designed to overcome the low sample size typical to mic…

A natural randomization process, sometimes called Mendelian randomization, occurs at conception to determine a person's genotype. By combining information from genotype-disease and genotype-phenotype studies, it is possible to use this Mendelian randomization to derive an estimate of the association between phenotype (…

Meta-analysis involves combining summary information from related but independent studies. The objectives of a meta-analysis include increasing power to detect an overall treatment effect, estimation of the degree of benefit associated with a particular study treatment, assessment of the amount of variability between s…

We consider the problems arising in clinical research on childhood acute lymphoblastic leukemia (ALL). Given the therapeutic progress achieved over the last few decades, any improvement in the outcome for the majority of children with ALL is difficult to assess with the usual size trials. Furthermore, the progress in g…

OBJECTIVE: To demonstrate how the results of a meta-analysis can confuse rather than clarify therapeutic dilemmas if clinical heterogeneity among trials is ignored. Then to further discuss the qualities emergency physicians should expect from published meta-analyses if they are to affect clinical practice. SUBJECTS AN…

A meta-analysis was done on grip strength, the most common variable in comparative NSAID trials. The median grip strength was 133 mm Hg (SD 64). The drugs were better than placebo (11.9 mm Hg, confidence interval (CI): 8.9-14.9), but the full dose was not significantly superior to half the dose (3.5 mm Hg, CI: -1.4 to…

Controversy persists over the best choice of fluid to use for resuscitation. A number of published articles promote the use of either colloid or crystalloid fluids. Most of the arguments for use of one fluid or the other are based on cardiopulmonary data collected during and after fluid resuscitation. Although many stu…

This article presents a stepwise approach for conducting a meta-analysis of epidemiological studies based on proposed guidelines. This systematic method is recommended for practitioners evaluating epidemiological studies in the literature to arrive at an overall quantitative estimate of the impact of a treatment. Bende…

AIM: No consensus exists on the ideal nutrition for preterm infants. This leads to significant practice variation. Fortification of expressed breast milk (EBM) and nutrient supplementation of the preterm infant's diet have become common practices to enhance growth. This systematic review aims to review the comparative…