A Retrospective Analysis of the Effects of Protocol Design on Completion Rates in Outpatient Clinical Trials in Subjects with Schizophrenia or Schizoaffective Disorder

Subject attrition from randomized Schizophrenia trials is a significant problem and has been found in a meta-analysis to be as high as 76%. The problem of drop-out is sometimes not addressed until the statistical analysis stage of a study which can decrease the validity of the results increasing the likelihood of a failed trial. The authors previously examined the effect of 9 trial design variables on individual completion in 11 Phase I trials in subjects with stable Schizophrenia or Schizoaffective Disorder at two clinical research sites in the period from 2009 to 2014 (Krefetz et al, 2015) The analysis showed that shortening the length of the inpatient period, increasing the outpatient period, and shortening the longest period between outpatient visits had a positive impact on completion.