Although randomized controlled trials (RCTs) play a key role in modern medicine, considerable variability exists in their quality and in the reliability (reproducibility) of their results. The present article discusses features that characterize high-quality trials, such as intent-to-treat (ITT) analysis, the avoidance of patient exclusions, and a procedure for evaluating the reliability of stu...

We study reactions to entry in a Cournot model, contrasting the case where firms are endowed with unchangeable technologies against that where technologies are flexible. By the latter we mean that firms can change the installed production technique at zero cost (fully flexible technologies). We show that when firms are technologically flexible, entry can increase equilibrium prices. The analysi...

The concept of evidence-based medicine has gained broad support in the medical community, because clinical decisions based on information from rigorous scientific study are most likely to provide optimal care. Researchers attempt to answer clinical questions using either observational studies or randomized controlled trials (RCTs). Observational studies currently dominate the surgical literatur...

OBJECTIVE The objective of this systematic review was to assess the effectiveness of yoga as a treatment option for asthma. METHOD Seven databases were searched from their inception to October 2010. Randomized clinical trials (RCTs) and non-randomized clinical trials (NRCTs) were considered, if they investigated any type of yoga in patients with asthma. The selection of studies, data extracti...

The randomized clinical trial (RCT) is generally accepted as the best method of comparing effects of therapies. Most often the aim of an RCT is to show that a new therapy is superior to an established therapy or placebo, i.e. they are planned and performed as superiority trials. Sometimes the aim of an RCT is just to show that a new therapy is not superior but equivalent to or not inferior to a...

OBJECTIVES Findings from nonrandomized studies on safety or efficacy of treatment in patient subgroups may trigger postlaunch randomized clinical trials (RCTs). In the analysis of such RCTs, results from nonrandomized studies are typically ignored. This study explores the trade-off between bias and power of Bayesian RCT analysis incorporating information from nonrandomized studies. STUDY DESI...

Randomized clinical trial (RCT) study design leads to one of the highest levels of evidence, and is a preferred study design over cohort studies, because randomization reduces bias and maximizes the chance that even unknown confounding factors will be balanced between treatment groups. Recent randomized clinical trials and observational studies in amblyopia can be taken together to formulate an...

OBJECTIVE The researchers sought to assess whether the widely used 1994 Cochrane Highly Sensitive Search Strategy (HSSS) for randomized controlled trials (RCTs) in MEDLINE could be improved in terms of sensitivity, precision, or parsimony. METHODS A gold standard of 1,347 RCT records and a comparison group of 2,400 non-trials were randomly selected from MEDLINE. Terms occurring in at least 1%...

The Journal of Antimicrobial Chemotherapy welcomes submissions of well-reported randomized controlled trials (RCTs) with solid methodology based on the CONSORT statement (http://www.consort-statement.org). The Journal would be especially happy to publish RCTs in the area of antimicrobial chemotherapy if they address significant problems and look at measurable outcomes that matter to patients.

background: this study aimed to assess the effectiveness of topiramate, a glutamate-modulating agent, in patients with treatment-resistant obsessive-compulsive disorder (ocd) as an adjunct to serotonin reuptake inhibitors (sris). materials and methods: thirty-eight patients with refractory ocd, were randomly assigned to receive topiramate or placebo. this study was designed as a 12-week, double...