Conducting a trial in a single centre removes between-centre heterogeneity, but when such trials (for example, those of early goal-directed therapy for severe sepsis [ 2] and of tight glycaemic control in critically ill patients [ 3]) find treatment effects, physicians can be reluctant to implement the findings if they suspect they were unique to the study institution [ 4, 5].
As a result, the protocol-specified time interval between radiological assessments used in clinical trials (for example, every 6 weeks vs every 12 weeks) may have an impact on the PFS, thus making cross-trial comparisons of clinical benefits with treatment particularly problematic.
For standard object recognition trials, for example as part of Experiment 1a, the rat now had a free choice between object A, now familiar, and novel object B (Trial 1; Table 1A; Fig. 1B).
Dudley Field Malone on return from Scopes trial, for example.
Trial-level factors apply to all patients in each trial: for example, drug dose.
The cluster design prevents potential "contamination" of the intervention between trial arms (if, for example, staff who had received the training at a unit randomised to receive the training were to move to a comparison unit).
111 Thirdly, there was heterogeneity between trial populations for example, in baseline lung function.
For a between-trial variance parameter, an example of a non-informative prior could be a gamma distribution with shape and scale parameters of both 10-10.
That is, unless a significant and undetected between-trial heterogeneity exists for the intervention effect, for example, outcomes incorrectly termed similarly, but representing different pathologies, in different trials.
Sixth, a systematic review of reasons may identify, as did ours, empirical assumptions that differ between publications, for example, assumptions about the cost, feasibility or legality of ensuring post-trial access to trial drugs.
