 This study examined the factors affecting the length of time it takes to get institutional review board, IRB, approval for clinical trials. It found that high workloads, low staff ratios, limited training, and the number and types of ancillary reviews all contribute to longer approval times. Additionally, billing coverage analysis and federally funded studies have shorter approval times than non-fedrally funded studies. Finally, variability in approval times among different institutions reviewing the same protocol can be seen when comparing phase three multi-site clinical trials. Overall, this study suggests that a quality improvement framework should consider both operational and study characteristics, as well as the larger institutional regulatory environment, in order to reduce unnecessary delays in obtaining IRB approval. This article was authored by Michael Callaguri, Karen Allen, Nate Busher, and others.