The growing volume and the diversity of clinical research has led to related laws and regulations as well as the Institutional Review Board (IRB) approval process becoming more stringent. To conduct clinical research efficiently and while following regulations, information about the IRB approval process and feedback is important for investigators. This has yet to be studied.

We included 381 gastrointestinal disease research proposals (79 with inflammatory bowel disease [IBD], and 302 with non-IBD) reviewed by the IRB of Severance Hospital between January 2009 and December 2013. We retrospectively analyzed research characteristics including research risk levels, results of initial reviews, frequencies of continuing review, numbers of IRB comments, frequencies of IRB comments, and durations from submission to approval.

Investigators' decisions on risk level were higher in the IBD group than in the non-IBD group (P<0.05). Results of initial reviews, frequencies of continuing reviews, the numbers of IRB review comments, and durations from submission to approval were not different between the two groups, but IRB decisions on risk level were higher in the IBD group (P<0.05). In subgroup analysis, the number of IRB comments from initial review on informed consent forms and procedures as well were quest of more information were significantly higher in the IBD group than in the non-IBD group (P<0.001 and 0.01, respectively).

In Korea, rare diseases such as IBD require more information for the IRB process due to their distinct characteristics. IBD researchers should develop research protocols more carefully and make their research as subject-friendly as possible.