OBJECTIVES To consider the effects of contamination on the magnitude and statistical significance (or precision) of the estimated effect of an educational intervention, to investigate the mechanisms of contamination, and to consider how contamination can be avoided. DATA SOURCES Major electronic databases were searched up to May 2005. METHODS An exploratory literature search was conducted. ...

OBJECTIVE Confirmatory randomised controlled trials require solid justifications, especially with regard to whether the experimental intervention is promising. Such evidence is generated in exploratory trials. However, empirical evidence shows that the quality of such trials is still suboptimal. More generally, the development process of healthcare interventions and especially of drugs, remains...

OBJECTIVE To investigate the planning of subgroup analyses in protocols of randomised controlled trials and the agreement with corresponding full journal publications. DESIGN Cohort of protocols of randomised controlled trial and subsequent full journal publications. SETTING Six research ethics committees in Switzerland, Germany, and Canada. DATA SOURCES 894 protocols of randomised contro...

BACKGROUND During thoracoabdominal aortic aneurysm (TAAA) surgery, decreased spinal cord perfusion can result in neurological deficits such as paraplegia and paraparesis. Distal aortic perfusion, alone or in combination with other adjuncts, may counter the decrease in spinal cord perfusion and hence reduce the risk of spinal cord injury. OBJECTIVES To determine the effectiveness of distal aor...

Objective To investigate the planning of subgroup analyses in protocols of randomised controlled trials and the agreement with corresponding full journal publications. DesignCohort of protocols of randomised controlled trial and subsequent full journal publications. Setting Six research ethics committees in Switzerland, Germany, and Canada. Data sources 894 protocols of randomised controlled tr...

OBJECTIVE To assess the quality of reported consent processes of cluster-randomised trials conducted in residential facilities for older people and to explore whether the focus on improving the general conduct and reporting of cluster-randomised trials influenced the quality of conduct and reporting of ethical processes in these trials. DESIGN Systematic review of cluster-randomised trials re...

BACKGROUND Randomised trials remain the gold standard for evaluating health interventions. This applies to the criminal justice system as well as to health. AIMS To identify and survey randomised trials relevant to forensic mental health services. METHOD We searched 29 electronic bibliographic databases and acquired randomised trials involving sex offenders, arsonists or people clearly and ...