Number of Countries in Phase III Studies Remains Steady

Are pharmaceutical company Phase III clinical trials becoming more complex? The most broadly based database available, ClinicalTrials.gov, does not support the assertion that clinical trials have become more complex in study/protocol design or execution. Illustrative is the number of countries used in pharmaceutical company sponsored Phase III clinical studies. 

The number of countries used in commercially sponsored Phase III trials has not changed in recent years. It is essential to stratify the results or otherwise the data appear to show that the number of countries per study has actually declined. The chart at right stratifies the studies by planned study duration: less than one year, 1 to 2 years and 3 or more years. This is important because the longer the planned study, the more likely the study may be opening sites in additional countries. When stratified this way, the data show practically no change over the years covered.