BMC Medical Research Methodology - Latest articlesThe latest articles from BMC Medical Research Methodology (ISSN 1471-2288) published by BioMed CentralSimpson's paradox visualized: The example of the Rosiglitazone meta-analysis- May 30, 2008 Background: Simpson's paradox is sometimes referred to in the areas of epidemiology and clinical research. It can also be found in meta-analysis of randomized clinical trials. However, though readers are able to recalculate examples from hypothetical as well as real data, they may have problems to easily figure where it emerges from.MethodFirst, two kinds of plots are proposed to illustrate the phenomenon graphically, a scatter plot and a line graph. Subsequently, these can be overlaid,...http://www.biomedcentral.com/1471-2288/8/34 On reporting results from randomized controlled trials with recurrent events- May 30, 2008 Background: Evidence-based medicine has been advanced by the use of standards for reporting the design and methodology of randomized controlled trials (RCT). Indeed, without this information it is difficult to assess the quality of evidence from an RCT. Although a variety of statistical methods are available for the analysis of recurrent events, reporting the effect of an intervention on outcomes that recur is an area that remains poorly understood in clinical research. The purpose of this...http://www.biomedcentral.com/1471-2288/8/35 Rasch fit statistics and sample size considerations for polytomous data- May 29, 2008 Background: Previous research on educational data has demonstrated that Rasch fit statistics (mean squares and t-statistics) are highly susceptible to sample size variation for dichotomously scored rating data, although little is known about this relationship for polytomous data. These statistics help inform researchers about how well items fit to a unidimensional latent trait, and are an important adjunct to modern psychometrics. Given the increasing use of Rasch models in health research the..http://www.biomedcentral.com/1471-2288/8/33 |