Our primary objective was to determine the proportion of trials that report the number of patients assessed for eligibility before randomization. We performed the systematic retrieval and analysis of all phase II, III, and IV RCTs published between 2013 and 2015 in four high-impact-factor journals in the field of clinical oncology. Among 456 RCTs reviewed, 236 trials (51.8%) reported the number of patients assessed for eligibility. Among the 236 trials that reported the entire enrollment process, the reasons for patient exclusion could be found in 184 trials (78%). A flow diagram was presented in 452 trials (99.1%), and 98 trials (21.5%) included a discussion on generalizability. Reporting the parameters of external validity in medical oncology RCTs is challenging. Improving adherence to the 2010 CONSORT guidelines concerning the enrollment process could help clinicians and health policymakers establish to whom trial results apply.
Keywords: CONSORT; external validity; oncology; randomized trials.