Drug treatment groups

Fig. 6 Effect of methylphenidate on Acquisition of the PAR in juvenile rat pups. Juvenile rat pups (day 15-16) were tested for acquisition of a multi-trial PAR. Littermates were equally divided into vehide or drug treatment groups. Methylphenidate salt was given ip at a dose of 3 mg/kg (base), 30 mins prior to training. Animals were returned to their home cage with their littermates for the intertrial time period. indicates statistically significant differences between drug-treatment group and vehide-treatment group at the specific trial. Non-parametric statistical analysis (Kruskal-Wallis test) was conducted on median latencies (sec). Mean + SEM entry latendes (sec) are presented (n = 12-18/group).

Calculate the difference between the mean change score for the drug treatment group and the mean change score for the placebo group, i.e., the effect size. 

In the present example, an effect size of 3.00 mmHg was observed. That is, the difference between the drug treatment group mean change score and the placebo treatment group mean change score was 3.00 mmHg. This effect size has been precisely calculated on the basis of the data obtained in the clinical trial. Recall, however, that in a randomized clinical trial the subjects used are a random sample of all the people in the disease population of interest. Our interest actually lies with the effect size in that population. The population effect size is not known, and a question of interest is How well does the effect size calculated in our sample reflect the unknown effect size in the population This question is at the heart of inferential statistics. 

Imagine that a randomized clinical trial was conducted to compare the mean change in SBP in the drug treatment group with the mean SBP change in the placebo treatment group, and the results were as follows ... 

Mean SBP decrease for the drug treatment group = 8.1 mmHg. 

The clinically relevant difference (CRD) that the test is required to detect. This is the treatment effect size, i.e., the difference between the mean drug treatment group response and the mean placebo treatment group response, that the sponsor deems clinically relevant. 

Table 10.2 provides an example of an in-text table that summarizes subject accountability. This in-text table of hypothetical data is identified by the title associated with it, and the information in the headers provides more detail concerning the. nature of the data presented. In this example, clinical trial ABC was conducted using a drug treatment group and a placebo treatment group, and data for the ITT population are presented. 

The drug treatment group and the placebo treatment group... 

The terms "drug treatment group" and "placebo treatment group" will become very familiar to you as you work your way through this book. Chapter 4 provides more detail, but it is helpful at this point to comment briefly on the following aspect of certain preapproval clinical trials. 

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