Retrospective study of online ligation student practice incorporating flipped learning into e-learning.

"Declarations Conflict of interestThe authors declare no conflicts of interest in association with the present study. Conflict of interest The authors declare no conflicts of interest in association with the present study."

"This study was approved by the Ethics Committee of Gunma University Hospital (registration number: HS2020-252) and was performed in accordance with the ethical standards of the 1964 Declaration of Helsinki and its later amendments. We verbally explained the study and questionnaire survey to the students and obtained their consent. We also disclosed the information and provided the opportunity to opt out of the study. We performed statistical analyses using JMP Statistical Discovery TM (ver. 15.2., SAS Institute Japan Ltd., Tokyo, Japan). Welch’s t test was used to determine whether the final exam score increased before or after the mid-term check, and to compare scores between experienced and inexperienced students. p Values of < 0.05 were considered statistically significant."