The 10-year increase in the number of unique and total procedures per protocol corresponds to an increase in the number of endpoints supported by these procedures. Research conducted by the Tufts Center for the Study of Drug Development (Tufts CSDD) finds that between 2004 and 2012, the number of endpoints per protocol has nearly doubled from an average of eight per protocol in the earlier period to 14 endpoints in the later period. Half of all procedures support supplemental secondary, tertiary, and exploratory endpoints—a proportion that has remained constant during this eight-year period. Sponsor companies have added more procedures for a variety of reasons: clinical scientists seek more contextual data to interpret and validate findings and guide development decisions; statisticians wish to collect more data to explain observations and potential new interactions; and sponsor companies also note that procedures supporting tertiary and exploratory endpoints are added in anticipation of perceived or real regulatory agency and payor inquiry, commercialization, and competitive pressures. 

—Tufts Center for the Study of Drug Development, 