Comparison of Rmi (Risk Malignancy Index) and Simple Rules Risk Model In Evaluation of Adnexal Masses Taking Histopathology As Gold Standard

Objective: To compare ultrasound grounded International Ovarian Tumor Analysis (IOTA) prediction models, specifically, the ADNEX models, the Simple Rules (SRs) and the Risk of Malignancy Index (RMI), for the adnexal masses’ diagnosis before any surgical intervention Study Design: Cross-sectional analytical study Place and Duration of Study: Obstetrics and Gynecology Department. Pakistan Emirates Military Hospital, Rawalpindi, Pakistan from Aug 2019 to Jun 2020. Methodology: Five hundred and twenty-four patients took part in this cross-sectional Analytical study. All findings on ultrasound were evaluated and prognostic models were used. Histopathology findings were used as standard for comparison. Diagnostic performances of the prediction models were assessed by estimating sensitivities, ROC curves, negative predictive values and positive predictive values, specificities, diagnostic odds ratios and negative and positive likelihood ratios. Results: The ROC under curves (AUC) areas for ADNEX models were 0.94 (0.92-0.96, 95% CI) with CA125 and 0.94 (0.91-0.96, 95% CI) without CA-125 for RMI I-III It was expressively advanced than AUC: 0.83 (CI95%, 0.80 to 0.86), 0.82 (CI95%, 0.78 to 0.86 and 0.87 (CI95% 0.83 to 0.90) (all p <0.0001). The CA-125 had a cut-off point of 10% in ADNEX model had the maximum precision (CI: 95%, 0.87 to 0.97) equated to other models. The SR model achieved 0.93 (95% CI 0.86 to 0.97) sensitivity and 0.86 (95% CI 0.82 to 0.89) specificity when not diagnosed was classified as definite (11.7%) malignant. Conclusions: ADNEX and Simple rules risk models were excellent for characterizing adnexal masses better than RMI in Pakistani patients.