Evaluating Performance of the Spetzler-Martin Supplemented Model in Selecting Patients With Brain Arteriovenous Malformation for Surgery

Background and Purpose—Our recently proposed point scoring model includes the widely-used Spetzler-Martin (SM)-5 variables, along with age, unruptured presentation, and diffuse border (SM-Supp). Here we evaluate the SM-Supp model performance compared with SM-5, SM-3, and Toronto prediction models using net reclassification index, which quantifies the correct movement in risk reclassification, and validate the model in an independent data set. Methods—Bad outcome was defined as worsening between preoperative and final postoperative modified Rankin Scale score. Point scores for each model were used as predictors in logistic regression and predictions evaluated using net reclassification index at varying thresholds (10%–30%) and any threshold (continuous net reclassification index >0). Performance was validated in an independent data set (n=117). Results—Net gain in risk reclassification was better using the SM-Supp model over a range of threshold values (net reclassification index=9%–25%) and significantly ...