(Part I)
by Áine Dillon

 Back in the mid 90’s, when I started out in the world of clinical research, there was a certain hauteur associated with working in Randomised Clinical Trials (RCTs). RCTs were the Theoretical Physics of the Natural Sciences. As for studies in the peri-approval/ post-authorization area...well you might as well have been counting pollen grains under a microscope. Roll on two decades and due to the competitive nature of health markets, determining safety and efficacy through RCTs is no longer sufficient, in isolation, to win market access. So, time to climb down from the ivory to tower, roll up those sleeves, and fully embrace the world of Pragmatic Clinical Trials (PCTs). Of course, the PCT concept is not new, having been introduced over half a century ago in the seminal paper published by Schwarz & Lellouch [1].  Pragmatic trials aim to measure the relative effectiveness of treatment strategies in real world clinical practise. Pragmatic and explanatory trials (which measure efficacy under ideal conditions, such as typical phase 3 RCTs) represent ends of a continuum rather than distinct entities (Thorpe et al, 2009)[2].  So why the need for PCTs? For most new market-approved treatments, the clinical evidence (mainly phase 3 RCTs) is still insufficient to fully guide clinicians and policy makers in choosing the optimal treatment for their patients. Pragmatic trials can help supplement this data with Real World Evidence (RWE).Non-Interventional Studies (NIS) such as Observational Studies & Patient Registries can also provide valuable RWE. They differ from PCTs, in that there is no randomisation used to assign a patient to a particular therapy. No additional diagnostic or monitoring procedures are applied to patients and epidemiological methods are used for the analysis of the collected data. In a recent report in the Economist Intelligence Unit[3], on the findings of a quantitative study conducted around drug development and market access, adaptive trial designs, patient-centric trials, precision medicine trials and real-world data trials consistently deliver against industry success criteria.


1.Schwartz, D. and Lellouch, J.Explanatory and pragmatic attitudes in therapeutical trials.J Chronic Dis.1967;20:637–6482. Thorpe, KE; et al. (2009), "A pragmatic-explanatory continuum indicator summary (PRECIS): a tool to help trial designers",J Clin Epidemiol,62(5):464475,doi:10.1016/j.jclinepi.2008.12.011,PMC26798243.