How many participants do you need to conduct historical control trials?

The continual search for new treatments is a vital part of modern health care, and finding new drugs to treat conditions like cancer and heart diseases is a lengthy and often expensive process. A new method of determining the number of participants needed for historical control trials has been developed by a Texas A&M University School of Public Health professor.

Randomized control trials, where some patients receive the new medication and others get a placebo, have long been the gold standard. In recent years the historical control trial has gained popularity in studies of personalized treatments that target specific disease subtypes or patient populations because of the limited number of qualified participants in such clinical trials. Historical control trials compare an experimental treatment with a control treatment that has already been completed. This method can serve as an effective alternative to randomized control trials; however, correctly determining how many subjects a trial needs remains challenging.

Gang Han, associate professor in the Department of Epidemiology and Biostatistics at the Texas A&M School of Public Health, recently published a paper exploring methods for determining the number of subjects needed for a trial, and introduced a new method that could be more effective and accurate than existing techniques, especially when sample sizes are small.

Published in the journal Pharmaceutical Statistics, the new method is described and compared against a popular existing method using both real examples of historical control trials and simulations.