On the day of the experiment, 30 min before the first sample trial, the rat was habituated to the empty open field for 5 min and then placed in the container for 25 min. After this preliminary habituation session, each animal underwent 2 sample trials and a test trial (Fig. 5).
A specific treatment plan was created based upon the results of each patient's radiographic measurements before and after a sample trial of the proposed clinical procedures.
As the trial was stopped before the sample size was reached, we post hoc decided to conduct sequential analysis to assess the results of significance testing taking sparse data and repetitive testing into consideration.
On completion of a sample run and test run, the trial ended, and the maze locked the animal in the test side of the home cage for 10 min, before beginning the sample run of the next trial.
This ranged from 1984 to 2005 but was skewed by a North American trial (20 participants) published in 1984, five years before the next trial in the sample was published, in 1989 [23].
We noted that omega-3 fatty acid supplementation reduced the risk of total mortality only when we included trials published before 2000, the sample size was less than 1000, the proportion of men in the population was more than 80%, or participants received alpha-linolenic acid.
Before starting the trial, the sample size of the study (310 patients) was calculated so that the non-inferiority of iobitridol (350 mgI/ml) in providing the same level of diagnostic information as iomeprol (400 mgI/ml) could be statistically demonstrated with 80% power and 5% type-one error.
A recent study of 100 patients, who underwent a 48-hour spontaneous breathing trial before extubation, underwent echocardiographic evaluation and NP sampling immediately before the trial commenced and at the end, before extubation.
Deviations of intervention effects far from the anticipated values should a priori be regarded as unlikely and this is one reason for using a lower statistical threshold to stop a trial before the planned sample size has been reached [ 33].
Sometimes there is limited information available before the trial, making it highly desirable to adjust the sample size after seeing actual trial data.
