382,148 papers found

A study has 2 evidence factors if it permits 2 statistically independent inferences about 1 treatment effect such that each factor is immune to some bias that would invalidate the other factor. Because the 2 factors are statistically independent, the evidence they provide can be combined using methods associated with m…

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Do HEMA-free adhesive systems have better clinical performance than HEMA-containing systems in noncarious cervical lesions? A systematic review and meta-analysis. da Silva TSP, de Castro RF, Magno MB, Maia LC, da Silva 3 Souza Júnior. J Dent 2018; 74: 1-14. SOURCE OF F…

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Single-visit or multiple-visit root canal treatment: systematic review, meta-analysis and trial sequential analysis. Schwendicke F, Göstemeyer G. BMJ Open 2017;7(2):e013115. SOURCE OF FUNDING: This study was funded by the authors and their institution. TYPE OF STUDY/D…

When enteral nutrition is indicated to prevent or to treat a patient with denutrition choosing between a nasogastric tube (NGT) and a percutaneous endoscopic gastrostomy (PEG) is not always an easy decision. In neurological patients with swallowing disturbances or in patients with head and neck tumors, PEG is associate…

Systematic reviews represent a specific type of medical research in which the units of analysis are the original primary studies. They are essential tools in synthesizing available scientific information, increasing the validity of the conclusions of primary studies, and identifying areas for future research. They are…

The publication of the updated individual patient data meta-analysis of the larger randomised trials of intravenous rt-PA for acute ischaemic stroke has re-opened the debate about how the treatment should be used in routine practice, and what information can be expected to emerge in the next 2-3 years from the ongoing…

Systematic reviews and meta-analyses are being submitted to, and being published by biomedical journals with increasing frequency. In order to maintain the utility of such publications and avoid misguidance it is important that these studies are conducted to a high standard. This article aims to provide guidance both f…

Meta-analysis is the statistical process of combining information from several studies addressing the same question. Meta-analyses based on individual patient data are far more reliable and informative than those based on summary statistics obtained from the trialists or extracted from the published literature. Meta-an…

Over the past years, systematic reviews and meta-analyses have led to significant changes in clinical medicine and health policy. To date, they can be viewed as the most objective instruments to answer clinical as well health policy questions. In addition, systematic reviews are an important tool to synthesize the enor…

Encouraged by recent studies on the MTHFR 677C>T polymorphism and breast cancer risk that suggested an association of the 677 TT genotype with increased breast cancer susceptibility in premenopausal women, we performed an analysis of the relationship between breast cancer risk and the MTHFR 677C>T polymorphism in 210 p…

Fasciolosis, caused by trematodes of the genus Fasciola, is an emerging disease of humans. One of the highest levels of human fasciolosis hepatica is found amongst the indigenous Aymaran people of the Northern Bolivian Altiplano. A meta-analysis of epidemiological surveys from 38 communities in the region demonstrates…

A risk ratio or difference from a meta-analysis is as many as ten steps away from the unobservable causal risk ratios and differences in target populations. The steps are like lenses, filters, or other fallible components of the epidemiologist's "telescope" for observing populations. Each step is another domain where d…

The objective was to review the current status of meta-analysis, the process of combining the results of similar investigations, which was described in 1976. It has evolved rapidly, and thousands have already been published. Meta-analysis may be performed in a narrative form or in the preferred statistical format, whic…

This article considers the dominant role of trials involving thousands of patients--the mega-trials--in cardiovascular disease. Problems with large trials mean that alternative strategies must be developed to aid the introduction of new drugs. The limitations of meta-analysis, and of trials with combined and surrogate…

Results from external studies often play an important role in many aspects of a clinical trial. Their incorporation into the decision making process of a trial, however, is rarely conducted in a formal manner. This conference will address what formal role, if any, meta-analytic summaries of external results should have…

Effectiveness research aims to base medical decision making more on rigorous evidence than on intuition and anecdote. The methods used to generate new data include, in order of decreasing rigor, clinical trials, observational studies, claims data analysis, and anecdotal studies. The methods that synthesize existing dat…