GlobalData analyzed average enrollment efficiency values for clinical trials with a start date from January 1, 2017 across a variety of therapeutic areas and indications. Enrollment efficiency corresponds to the percentage achievement of the targeted enrollment population, where a value of 100% indicates that enrollment targets have been met.

The majority of the clinical trials initiated in this timeframe (78.6%) did not have contract research organization (CRO) involvement. A total of 19.6% of clinical trials had enrollment efficiency data available; of these, only 35.6% had CROs involved in the organization and conduct of their trials. Across all phases, better average enrollment efficiencies were attained with CRO involvement.

The greatest discrepancies in values were obtained in Phase IV clinical trials, where enrollment targets were exceeded in CRO involved trials (105.8%) and targets were not met in trials without CRO involvement (80.5%). Similar findings were observed in Phase III clinical trials, where CRO involvement resulted in the achievement of average enrollment efficiency values beyond the proposed target enrollment (108.7%), and trials without a CRO involved failed to meet planned targets (96.2%).

Although CRO involvement may be responsible for higher average enrollment efficiency values in Phase I and II clinical trials, enrollment in these clinical trials still fell below target values in both categories, despite these trials typically being smaller in size than their Phase III and IV counterparts.

This highlights the requirement for improved methods of enrollment in these earlier stage clinical trials. The most frequently investigated areas in Phase I and II trials were “Unspecified” indications and “Type 2 Diabetes”. These data also highlight the highly beneficial participation of CROs in larger Phase III and IV clinical studies.