Some worry that it is unethical to conduct a randomised trial – where half the schools or pupils are given one intervention, and half another – because it means some aspects of a child's education are determined arbitrarily.
However, in the study by Curtis et al [ 9] all patients received guideline-based care (advice and paracetamol) with half randomised to also receive a course of spinal manipulative therapy.
Two groups of 25 nephrologists were exposed to the six randomised combinations of half-life and administration interval.
The gold standard for research is the randomised controlled trial, where half the people receive the treatment and the other half don't.
The exposed group in the database study, however, was smaller than the treated cohort in half the randomised controlled trials.
Owing to the design of randomised controlled trials, roughly half of monitoring activities are conducted in control areas.
They explain the large prevalence difference with the available literature by including more prospective trials (50%% half of which randomised trials) that lack the confounder of patient selection of retrospective trials.
Almost half of all randomised patients were not available for a CC analysis.
Indeed, in the FREE trial almost half of all randomised patients were not available for the CC analysis.
In response to a questionnaire, 72% of participants in this non-randomised study said they would participate in a randomised trial in which only half the participants were treated during the trial.
