The Statistical Comparison of Clinical Trials

Being able to compare clinical trials using statistically proven analyses is essential, but certain protocols must be followed if such a comparison is to be made. The difficulty of making meaningful statistical comparisons is illustrated in 5 clinical trials comparing atypical antipsychotics. Certain judgments can be made on the basis of internal and external validity, for example, but there are many other areas—effect size, for example—in which it is impossible to make any statistical comparisons across these trials because they were not conducted in a uniform fashion. In the final analysis, it is doubtful that the differences between atypical antipsychotics covered in these trials are greater than those due to chance.