386,649 papers found

In a meta-analysis of diagnostic accuracy studies, the sensitivities and specificities of a diagnostic test may depend on the disease prevalence since the severity and definition of disease may differ from study to study due to the design and the population considered. In this paper, we extend the bivariate nonlinear r…

PURPOSE: Systematic reviews and meta-analysis of published clinical datasets are important part of medical research. By combining results of multiple studies, meta-analysis is able to increase confidence in its conclusions, validate particular study results, and sometimes lead to new findings. Extensive theory has been…

Obesity among children and adults has become a highly recognized public health concern and there is an increasing need to discover causes and evaluate preventative measures. One putatively causal influence on obesity is breastfeeding (BF). The World Health Organization (WHO) recently published a report (WR) on 'Evidenc…

BACKGROUND: Meta-analysis of continuous outcomes traditionally uses mean difference (MD) or standardized mean difference (SMD; mean difference in pooled standard deviation (SD) units). We recently used an alternative ratio of mean values (RoM) method, calculating RoM for each study and estimating its variance by the de…

BACKGROUND: Several approaches are available for evaluating heterogeneity in meta-analysis. Sensitivity analyses are often used, but these are often implemented in various non-standardized ways. METHODS: We developed and implemented sequential and combinatorial algorithms that evaluate the change in between-study hete…

BACKGROUND AND AIMS: A great deal of money is spent controlling invasive weeds as part of international and national policies. It is essential that the funded treatments work across the region in which the policies operate. We argue that experiments across multiple sites are required to validate these programs as resul…

One of the least well understood regions of the human brain is rostral prefrontal cortex, approximating Brodmann's area 10. Here, we investigate the possibility that there are functional subdivisions within this region by conducting a meta-analysis of 104 functional neuroimaging studies (using positron emission tomogra…

OBJECTIVE: To evaluate the overall diagnostic capabilities of frequency-doubling technology (FDT) in patients of primary glaucoma, with standard automated perimetry (SAP) and/or optic disc appearance as the gold standard. METHODS: A comprehensive electric search in MEDLINE, EMBASE, Cochrane Library, BIOSIS, Previews,…

BACKGROUND: In meta-analyses of clinical trials, clinicians are often interested in examining subset effects. Meta-regression of aggregated data is a usual approach for relating sources of variation in treatment effects to specific study characteristics. However, it is known that study-level analyses can lead to biased…

Therapeutic goals for atrial fibrillation (AF) include ventricular rate control, stroke prevention, conversion to normal sinus rhythm, and maintenance of normal sinus rhythm. The optimal strategy of rate versus rhythm control for acute management of patients with AF is a continuing debate. However, selected patients ma…

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…

This systematic review aimed to collate randomized controlled trials (RCTs) of various interventions used to treat tardive dyskinesia (TD) and, where appropriate, to combine the data for meta-analysis. Clinical trials were identified by electronic searches, handsearches and contact with principal investigators. Data we…

OBJECTIVE: To quantify the impact of duplicate data on estimates of efficacy. DESIGN: Systematic search for published full reports of randomised controlled trials investigating ondansetron's effect on postoperative emesis. Abstracts were not considered. DATA SOURCES: Eighty four trials (11,980 patients receiving onda…

Using data from a meta-analysis of the effects of oestrogen replacement therapy on the development of breast cancer, we compared alternative methods for combining dose-response slopes from epidemiological studies. We evaluated issues related both to summarizing data from single studies and to combining results from mul…