381,819 papers found

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…

A series of studies have been published that evaluate the chromosomal copy number changes of different tumor classes using array comparative genomic hybridization (array CGH); however, the chromosomal aberrations that distinguish the different tumor classes have not been fully characterized. Therefore, we performed a m…

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A major problem for meta-analysis of multiple outcomes is the unavailability of some estimates from published and unpublished studies.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…

This article continues a series of reports on recent research developments in the field of heart failure. Key presentations made at the European Society of Cardiology Heart Failure Update meeting, held in Wroclaw, Poland, in June 2004 are reported. The SHAPE study identified a need to educate general practitioners (GPs…

Meta-analyses are being undertaken in an increasing diversity of diseases and conditions, some of which involve outcomes measured on an ordered categorical scale. We consider methodology for undertaking a meta-analysis on individual patient data for an ordinal response. The approach is based on the proportional odds mo…

We applied a mixed effects model to investigate between- and within-study variation in improvement rates of 180 schizophrenia outcome studies. The between-study variation was explained by the fixed study characteristics and an additional random study effect. Both rate difference and logit models were used. For a binary…

We developed and evaluated methods for the analysis and interpretation of the baseline risk heterogeneity in meta-analysis of individual patient data (MIPD) based on information on predictive factors. We used data from a typical MIPD of eight clinical trials (1792 patients, 2947 years of follow-up) on the efficacy of h…

OBJECTIVE: We conducted this meta-analysis to determine the magnitude of risk conferred by bacterial vaginosis during pregnancy on preterm delivery. SEARCH STRATEGY: We selected articles from a combination of the results of a MEDLINE search (1966-1996), a manual search of bibliographies, and contact with leading resea…

For meta-analysis, substantial uncertainty remains about the most appropriate statistical methods for combining the results of separate trials. An important issue for meta-analysis is how to incorporate heterogeneity, defined as variation among the results of individual trials beyond that expected from chance, into sum…

OBJECTIVES: Head injury is a common event. Most patients sustain a mild head injury (MHI), and management depends on the risk of an intracranial haemorrhage (ICH). The value of a plain skull radiograph as a screening tool for ICH is controversial. The aim of this meta-analysis was to estimate and explain differences in…

The identification of heterogeneity in effects between studies is a key issue in meta-analyses of observational studies, since it is critical for determining whether it is appropriate to pool the individual results into one summary measure. The result of a hypothesis test is often used as the decision criterion. In thi…

Overviews that combine single effect estimates from published studies generally use a summary statistic approach where the effect of interest is first estimated within each study and then averaged across studies in an appropriately weighted manner. Combining multiple regression coefficients from publications is more pr…

Systematic reviews have a central role in evidence-based medicine. The quantitative systematic review, also known as meta-analysis, provides a logical structure for quantifying evidence and for exploring bias and diversity in research systematically. It is essential that clinicians, educators, and researchers understan…

We have applied meta-analysis to investigate the relationship between birth place and the likelihood of neonatal survival, for infants of low birth weight (less than 2501 grams) in a series of 19 non-randomized studies. This paper illustrates the utility meta-analysis in evaluating medical technologies described in non…

Intermediate thickness (0.76-1.69 mm) clinical stage I melanomas at BANS locations (upper Back, posterior Arm, posterior Neck, posterior Scalp) were initially reported to have worse prognosis than similar thickness lesions at other subsites. Subsequent investigation did not support this observation. We re-examined the…

Network meta-analyses (NMAs) of seasonal vaccines face distinct challenges that can compromise the validity and relevance of findings. While established frameworks offer guidance for evaluating the feasibility of NMAs, they do not address factors specific to seasonal vaccines. This study aims to highlight unique method…

INTRODUCTION: Depression is a common complication of stroke that adversely affects functional recovery. Although a wide range of pharmacological and non-pharmacological interventions are used in clinical practice, evidence regarding their comparative efficacy and acceptability remains inconclusive. Therefore, we will c…

INTRODUCTION: Exergaming shows great potential in the intervention of individuals with mild cognitive impairment (MCI). However, further research is needed on the use of exergaming in people with MCI. The current evidence of the use of exergaming in MCI has conflicting results. Which kind of exergaming is the most effe…

BACKGROUND: Intravenous loop diuretics are the cornerstone of acute heart failure treatment. Diuretic resistance limits the efficacy and reduces the effectiveness of decongestion, which is associated with increased mortality in AHF patients. We aim to investigate the effect of adding hypertonic saline solution (HSS) to…