382,895 papers found

SUMMARY: MASS is a command-line program to perform meta-analysis of sequencing studies by combining the score statistics from multiple studies. It implements three types of multivariate tests that encompass all commonly used association tests for rare variants. The input files can be generated from the accompanying sof…

SUMMARY: Compilation of genetic maps combined to quantitative trait loci (QTL) meta-analysis has proven to be a powerful approach contributing to the identification of candidate genes underlying quantitative traits. BioMercator was the first software offering a complete set of algorithms and visualization tool covering…

Systematic reviews are designed to answer a focused clinical question. They employ a predetermined explicit methodology to comprehensively search for, select, appraise, and analyze studies. Meta-analysis is the statistical pooling of the results of studies that are part of a systematic review. Systematic reviews are re…

The random-effects model is often used for meta-analysis of clinical studies. The method explicitly accounts for the heterogeneity of studies through a statistical parameter representing the inter-study variation. We discuss several iterative and non-iterative alternative methods for estimating the inter-study variance…

In a random-effects meta-analysis, a new confidence interval for the heterogeneity parameter is proposed. With this interval, the amount of heterogeneity in a meta-analysis can be assessed so that it can be judged whether the pooling of the estimates is meaningful. Through suitable corrections of the lower bound, based…

It has been suggested that the standard test for the presence of heterogeneity in meta-analysis has low power. Although this has been investigated using simulation, there is little direct analytical evidence of the validity of this claim. Using an established approximate distribution for the test statistic, a procedure…

Perhaps the greatest threat to the validity of a meta-analysis is the possibility of publication bias, where studies that are interesting or statistically significant are more likely to be published than those with less encouraging results. In particular, there is the concern that this bias might be 'one-sided', where…

BACKGROUND: Although publication bias is a concern when using meta-analysis, techniques for assessing for its potential appear to be underused in nursing. OBJECTIVES: To demonstrate several methods, both graphical and statistical, of assessing for publication bias. METHODS: Four methods are described and demonstrated…

Empirical Bayes meta-analysis provides a useful framework for examining test validation. The fixed-effects case in which rho has a single value corresponds to the inference that the situational specificity hypothesis can be rejected in a validity generalization study. A Bayesian analysis of such a case provides a simpl…

Meta-analysis is a systematic, quantitative approach to the combination of data from several clinical trials that address the same question. This analytic approach can help resolve questions that remain unclear from the results of individual trials. Meta-analysis is of particular interest in oncology because of the sma…

The overall effect of antihypertensive drug treatment has been well documented. The proportion of patients who benefit varies according to their baseline cardiovascular risk, and is small for the majority of people treated. Some investigators propose limiting the treatment target population to patients at high cardiova…

The paper discusses some of the most common criticisms to meta-analysis presented by Professor Feinstein in this Conference. As many of the points raised in his contributions are not new, a critique to them is presented in the context of the type of contribution given by systematic reviews (meta-analysis) to the analys…

BACKGROUND: Meta-analysis is now widely used in order to increase the power of individual clinical studies. Important far-reaching conclusions have been derived by pooling the results of studies which in isolation would not be large enough to reach definitive conclusions. While the statistical power is thereby amplifie…

Meta-analysis is the process of formally combining the quantitative results of separate studies in order to increase the statistical precession of estimated effects. It has become fashionable when individual studies fail to yield conclusive results. A recent update of a meta-analysis (overview) for treatments of patien…

Meta-analysis is a technique for summarizing the results of many studies which can allow reviewers in a particular field to arrive at a synthesis of the various findings in a more objective manner than relying on expert opinion and combine the results of these studies to arrive at an overall estimate of the magnitude o…

Bowen's disease frequently has been reported to be associated with internal malignancy, although this association has been extremely controversial. The present study uses the technique of meta-analysis to address this issue by pooling the results of the 12 studies published in the English-language literature that previ…

A meta-analysis of studies on consumer satisfaction with medical care yielded 221 studies that reported relations between satisfaction and other variables, of which 107 reported satisfaction levels for two or more aspects of medical care. A method was developed to derive the relative levels of patient satisfaction with…

INTRODUCTION: An increasing number of randomised controlled trials (RCTs) have compared the analgesic effects of erector spinae plane block with those of intercostal nerve block for postoperative analgesia in various surgeries, but the results have been inconsistent. This protocol of a systematic review and meta-analys…

INTRODUCTION: In light of the rising prevalence of sedentary behaviour worldwide, its impact on health has become a subject of growing interest. To clarify whether there is a significant correlation between sedentary behaviour and chronic pelvic pain in women and to explore its potential clinical implications, this stu…

BACKGROUND: Improving patient outcomes will be enhanced by understanding "what works, for whom?" enabling better matching of patients to available treatments. However, answering this "what works, for whom?" question requires sample sizes that exceed those of most individual trials. Conventional methods for combining da…