OBJECTIVE The lack of a standard methodology in diagnostic research impedes adequate evaluation before implementation of constantly developing diagnostic techniques. We discuss the methodology of diagnostic research and underscore the relevance of decision analysis in the process of evaluation of diagnostic tests. STUDY DESIGN AND SETTING Overview and conceptual discussion. RESULTS Diagnost...

Well-conducted randomized clinical trials (RCT) are essential for the objective assessment of the value of new diagnostic or therapeutic medical interventions. They also will give us information about the effect of the intervention on cost and quality of life. Although the RCT was introduced 50 years ago, the requirements to ensure the best possible quality are continuously scrutinized.1–4 That...

BACKGROUND If trials of therapeutic interventions are to serve society's interests, they must be of high methodological quality and must satisfy moral commitments to human subjects. The authors set out to develop a clinical-trials compendium in which standards for the ethical treatment of human subjects are integrated with standards for research methods. METHODS The authors rank-ordered the w...

Meta-analysis of multi-arm trials has been used increasingly in recent years. The aim of meta-analysis for multi-arm trials is to combine evidence from all possible similar studies. In this paper we propose normal approximation models by using empirical logistic transform to compare different treatments in multi-arm trials, allowing studies of both direct and indirect comparisons. Additionally,...

The REACH Forgiveness intervention has been used in psychoeducational groups, couple and individual counseling and psychotherapy, and workbooks. It has been investigated in over 20 randomized clinical trials (RCTs) worldwide. It has been accommodated to treat Christians and shown to be effective in RCTs. But most research has established it to be effective when not accommodating it to religious...

There is currently no International Standard suitable for the standardization of assays of vaccines from the manufacturer. The manufacturer has therefore established a product-specific reference preparation which is traceable to a lot of vaccine shown to be efficacious in clinical trials. This vaccine will serve as a working standard and will be included in all potency tests. The NRA approves t...

This paper briefly describes Jerome Cornfield's approach to Bayesian statistics, his discomfort with frequentist inference, and his contribution to two major clinical trials, the University Group Diabetes Program and the Coronary Drug Project. I mention the role of Bayesian statistics in current randomized clinical trials and conjecture why Cornfield's contributions to Bayesian methods are not ...

BACKGROUND Noncompliance to treatment assignment is an inevitable occurrence in randomized clinical trials (RCTs). Intention to treat (ITT) is generally considered the best method for addressing noncompliance in RCTs. Alternatives to ITT exist, including per protocol (PP), as treated (AT), and instrumental variables (IV). These three methods define participant compliance dichotomously, but part...

After a non-inferiority clinical trial, a new therapy may be accepted as effective, even if its treatment effect is slightly smaller than the current standard. It is therefore possible that, after a series of trials where the new therapy is slightly worse than the preceding drugs, an ineffective or harmful therapy might be incorrectly declared efficacious; this is known as 'bio-creep'. Several ...

BACKGROUND Recruitment to clinical trials is often problematic, with many trials failing to recruit to their target sample size. As a result, patient care may be based on suboptimal evidence from underpowered trials or non-randomised studies. METHODS For many conditions patients will require treatment on several occasions, for example, to treat symptoms of an underlying chronic condition (suc...