392,095 papers found

It is widely assumed that body image dissatisfaction is increasing, particularly in females. We examined data from comparable samples, University of Pennsylvania introductory psychology students, over a span of about 15 years (1983-1984 versus 1995-1998). Ratings of current and ideal body figure were obtained using sil…

Numbers needed to treat (NNTs) may be used to present the effects of treatment and are the reciprocal of the absolute difference between treatment and control groups in a randomized controlled trial. NNTs are sensitive to factors that change the baseline risk of trial participants: the outcome considered; characteristi…

The random effects model is often used in meta-analyses. A corresponding significance test based on a normal approximation has been established. Its type I error is derived in this article by theoretical considerations and computer simulations. The test can be conservative as well as unacceptably anti-conservative. The…

Although laboratory stress research is a popular and vibrant area of research activity, there is surprisingly little evidence that laboratory stress models are clinically useful (i.e. that they can explain and predict the development of disease). This article summarizes evidence that the usefulness of lab stress resear…

This paper reviews recent developments in the area of computer-assisted analysis of mixture distributions (C.A.MAN). Given a biometric situation of interest in which, under homogeneity assumptions, a certain parametric density occurs, such as the Poisson, the binomial, the geometric, the normal, and so forth, then it i…

According to an unreliable meta-analysis, epoetin beta reduces the number of premature neonates needing transfusions for anaemia by 18% on average. When such children do require transfusions, two comparative trials have shown a reduction in the frequency of transfusions and total volume of blood transfused, but the cli…

The reliable detection of moderate differences in major health outcomes that arise as a result of treatment requires large-scale randomized evidence (and the appropriate interpretation of this evidence once it has been generated). This may take the form of a single mega-trial or, exceptionally, a meta-analysis of many…

The concept that patients with advanced prostate cancer will survive longer if treated by a combination of castration and the blockade of androgens of non-testicular origin cannot be substantiated. When all of the available studies are reviewed, meta-analysis does not show any significant improvement in mortality when…

Research review has long been one of the most important scholarly activities in all branches of science. While there is sometimes a single study so well-designed, well carried out, and difficult to replicate that its findings are accepted as conclusive, more often there are many studies on a given topic, no one of whic…

I begin by considering origins and meanings for the term met-analysis/meta-analysis. The underlying ideas have a long history, not only in medical but also in the agricultural and social sciences. Met-analysis is a form of critical review of research on a stated topic, distinctive for its emphasis on producing quantita…

Studies carried out over the last 12 years in northern Italy on a case list of 105 cadmium (Cd) workers showed that blood levels (B-Cd) were influenced not only by current exposure but also by body burden, while urinary levels (U-Cd) were influenced predominantly by body burden. Moreover, no advantages were gained by a…

The results of therapeutic trials of Class I antiarrhythmic agents after myocardial infarction are not identical or always compatible with those of the CAST. It is important to determine the reason for this disparity in order to try and identify the patients who should not be given these drugs and those in whom they co…

Our efforts to identify published articles describing meta-analyses of clinical trials illustrate the need for standard terminology to facilitate retrieval. We found 119 articles describing meta-analyses and eligible for inclusion in MEDLINE, and yet when we searched MEDLINE, using strategies based on textwords and med…

Limited evidence on relative effectiveness is common in Health Technology Assessment (HTA), often due to sparse evidence on the population of interest or study-design constraints. When evidence directly relating to the policy decision is limited, the evidence base could be extended to incorporate indirectly related evi…

The conduct of dose-finding trials can be specifically challenging in small populations, for example, in pediatric settings. Recently, research has shown that Bayesian borrowing from adult trials combined with appropriately robust prior distributions enables the conduct of pediatric dose-finding trials with very small…

BACKGROUND: Inconsistency has been reported to be ubiquitous in network meta-analysis. However, this evidence is based on statistical tests for inconsistency with well-documented power limitations. A novel interpretation index was developed that is founded on the Kullback-Leibler divergence measure and warrants a semi-…

Cellular therapy is a promising treatment option for Peripheral Arterial Disease (PAD). Different cell types can be used to regenerate and repair tissues affected by PAD. Many studies have proposed the use of stem cells, such as mesenchymal stem cells, or even mononuclear cells isolated from peripheral blood or bone ma…

BACKGROUND: The current practice in guideline development is to use the control group event rate (CR) as a surrogate of baseline risk and to assume portability of the relative treatment effect across populations with low, moderate and high baseline risk. We sought to emulate this practice in a very large sample of meta…

OBJECTIVES: To explore the use of prediction interval (PI) for the simultaneous evaluation of the imprecision and inconsistency domains of Grading of Recommendations, Assessment, and Evaluation using stakeholder-provided decision thresholds. STUDY DESIGN AND SETTING: We propose transforming the PI of a meta-analysis f…

OBJECTIVES: To review methodological guidance for nonlinear covariate-outcome associations (NL), and linear effect modification and nonlinear effect modification (LEM and NLEM) at the participant level in individual participant data meta-analyses (IPDMAs) and their power requirements. STUDY DESIGN AND SETTING: We…