IOTA phase 5 (interim analyses 1): Examination of short and long term outcomes of conservative management of benign-looking adnexal masses and the pre-operative characteristics of ovarian tumours

This is the first interim data of phase 5 of the IOTA study. This dataset contains the data of 8519 prospectively recruited patients presenting with at least one adnexal mass collected in 36 centers from 14 countries between 2012 and 2015, who were managed by surgery or follow-up. Additionally, the dataset of one center is uploaded seperately. This dataset contains the data of 2654 prospectively recruited patients presenting with at least one adnexal mass collected in a center in a low-risk setting between 2012 and 2016, who were managed by surgery or follow-up. The overall aim of the IOTA phase 5 study is the development of the optimal algorithm for the management of all adnexal masses. The specific objectives for the 2-year interim analysis are: (1) To study the 2-year occurrence of complications in patients with benign looking conservatively treated masses and (2) To test the published IOTA diagnostic models for predicting the risk that a mass is malignant at first visit.