382,346 papers found

A meta-analysis of the reliability of the scores from a specific test, also called reliability generalization, allows the quantitative synthesis of its properties from a set of studies. It is usually assumed that part of the variation in the reliability coefficients is due to some unknown and implicit mechanism that re…

Surgical approach for radical prostatectomy is even today a subject of debate in the urologic community. Many comparative studies between retropubic and laparoscopic approach (robotic assisted or not) were reported since 10 years without being able to decide between the supporters of retropubic or laparoscopic app…

BACKGROUND: The exponential rise in published medical research on a yearly basis demands a method to summarise best evidence towards its application to patient care in clinical practice. A robust meta-analysis is a valid tool. It is often considered to be a simple process of pooling results from different studies. This…

Systematic reviews with meta-analysis of studies on diagnostic tests or prognostic factors are research tools that are still being developed. The objective of the present paper is to describe the methodology of systematic review and meta-analysis of this type of studies, step by step. A literature review on the subject…

The use of standard univariate fixed- and random-effects models in meta-analysis has become well known in the last 20 years. However, these models are unsuitable for meta-analysis of clinical trials that present multiple survival estimates (usually illustrated by a survival curve) during a follow-up period. Therefore,…

Meta-analysis of individual patient data (MIPD) is considered as one of the statistical approaches to provide integrated information on the effect of a treatment or an intervention. Statistical analysis of such meta-analyses should account for the clustered structure of data which is induced by all factors varying acro…

Although spondylitis is the most common of the complications of brucellosis, and is often debilitating and difficult to treat, there is no consensus on the preferred combination of antibiotics used. We attempted to perform a meta-analysis based on series on brucellar spondylitis published in the last 22 years. Meta-ana…

Systematic literature reviews with meta-analysis of reported data in diagnostic research studies about the accuracy of tests assist clinicians in decision-making. However, there are limitations to this approach as the analysis of such data often does not allow reviewers to explore the diagnostic information gained from…

Among clinical trials assessing a given treatment, often parallel and cross-over designs are used together. In the first paper of a series of three, we explore two methods to pool continuous outcomes in a meta-analysis combining parallel and cross-over trial designs: the weighted mean difference (WMD) and the standardi…

Meta-analyses are subject to bias for many of reasons, including publication bias. Asymmetry in a funnel plot of study size against treatment effect is often used to identify such bias. We compare the performance of three simple methods of testing for bias: the rank correlation method; a simple linear regression of the…

Meta-analysis is a popular tool for combining evidence from several related studies. The technique is usually used to combine randomized clinical trials, case-control studies or prospective studies where each study has its own exposed and unexposed groups. By including separate 'study effects' (either fixed or random),…

Sequential designs are now a familiar part of clinical trial methodology. In particular, the triangular test has been used in several individual studies. Methods of combining studies are also well-known from the literature on meta-analysis. However, the combination of the two approaches is new. Consider the situation w…

Meta-analysis was proposed more than 20 years ago as an innovative technique for pooling the results of a series of clinical studies. This technique has a two-fold purpose: i) to retrieve pertinent clinical information without introducing selection biases; ii) to combine these clinical data obtained from different sour…

Reliable syntheses are more and more needed by physicians. In the therapeutic field, this need is illustrated by the growing number of syntheses using meta-analysis tools. Some of these syntheses are based on individual patient data, and this offers three kinds of advantages: the favourable consequences of a collaborat…

A fairly new type of research, termed meta-analysis, attempts to analyze and combine the results of previous reports. In 1992 we updated our 1987 survey of 86 meta-analyses of randomized control trial reports in the english language literature with an additional 78. We evaluated the quality of these meta-analyses using…

Use of meta-analytical (quantitative overview) techniques is now commonplace in a large range of medical-research contexts, with a rapid rise in its frequency of use being particularly apparent in the last decade. Many methods of meta-analysis have been proposed and used, from crude 'vote-counting' of studies showing s…

A meta-analysis of all nine available controlled trials of corticosteroids for adjunctive therapy for bacterial meningitis was performed. Risks of various outcomes were assessed for control and treatment groups from each study, and risk differences were determined. For each outcome a weighted average of the individual…

BACKGROUND: Intensive care unit-acquired weakness (ICU-AW) is an acquired neuromuscular lesion and a common occurrence in patients who are critically ill. We will systematically summarize and incorporate the important risk factors and prevalence from previously published multivariate analyses for ICU-AW. METHODS: We w…

Several researchers have relied on, or advocated for, internal meta-analysis, which involves statistically aggregating multiple studies in a paper to assess their overall evidential value. Advocates of internal meta-analysis argue that it provides an efficient approach to increasing statistical power and solving the fi…

In this column, we comment on the state of the science regarding psychotherapy for youths (including children and adolescents) with depression. We begin by discussing our recent meta-analysis of the youth depression clinical trials literature to illustrate how meta-analysis can be of use to clinicians. We consider how…