Personalising the risk of conversion from laparoscopic to open hysterectomy in benign conditions: Development and external validation of risk prediction models.

Abstract

To develop and validate novel prediction models to personalise the risk of conversion from laparoscopic to open hysterectomy in benign conditions. Retrospective cohort study. English NHS Hospitals between 2011 and 2018. 68752 women undergoing laparoscopic hysterectomy for benign conditions. We developed two multivariable logistic models using readily available clinical information, one for the pre-operative setting and another for operative decision-making using additional surgical information, using 2011-2016 data in five regions (24806 women). We validated them (a) temporally in the same regions using 2017-2018 data (12438 women); (b) geographically in the same time-period using data from three different regions (22024 women); and (c) temporally and geographically using 2017-2018 data in three different regions (9484 women). Conversion from laparoscopic to open hysterectomy. Conversions occurred in 6.8% (1687/24806) of hysterectomies in the development group, and in 5.5% (681/12438) in the temporal, 5.9% (1297/22204) in the geographical and 5.2% (488/9484) in the temporal and geographical validation groups. In the development cohort, the area under the receiver operating characteristic curve values for the pre-operative and operative models were 0.65 and 0.67, respectively. In the validation cohorts the corresponding values were 0.65 and 0.66 (temporal), 0.66 and 0.68 (geographical) and 0.65 and 0.68 (temporal and geographical), respectively. Factors predictive of conversion included age, Asian ethnicity, obesity, fibroids, adenomyosis, endometriosis and adhesions. Adhesions were the most predictive (odds ratio 2.54, 95% confidence interval 2.22-2.90). The models for predicting conversions showed acceptable performance and transferability. Novel tool to personalise the risk of conversion from laparoscopic to open hysterectomy in benign conditions.