Skip to Content  Predict the duration of your clinical trial
simon66217's picture  Researchers overpromise and undeliver on
patient accrual, the time frame in which they plan to obtain the
proposed sample sizes for their research studies. It is not
uncommon for a researcher to promise to get 100 patients within
a year, but then struggle to get even a dozen patients after two
years. Slow patient accrual leads to delays in completion of the
study or sample size shortfalls or both. This creates
substantial costs to the researcher but it also raises critical
issues for the ethical oversight for these studies by the
Institutional Review Board (IRB) and the Data Safety and
Monitoring Board (DSMB).  We have developed a formal Bayesian
model for accrual. It is a simple model with homogenous accrual:
a constant accrual rate across the entire study and exponential
waiting times between successive patients. The Bayesian model
requires specification of a prior distribution, which forces the
researcher to document expect