To compare the associations between frailty indices and postoperative complications among older adults undergoing common urologic procedures. Frailty is known to be strongly associated with poor postoperative complications; however, the optimal way to measure frailty remains unknown.

We identified the 20 most common urologic procedures from 2013-2016 in the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. Frailty was measured using the NSQIP frailty index, simplified frailty index, and Risk Analysis Index. Multivariable logistic regression models were performed with each index and the American Society of Anesthesiologists (ASA) classification system with postoperative complications (any, major, or minor) as the outcomes. Statistical models were compared using the following fit parameters: area under the curve, Akaike information criterion, and Bayesian information criterion.

A total of 158,855 procedures were identified. All frailty indices (NSQIP frailty index, simplified frailty index, and Risk Analysis Index) and ASA were associated with increased odds for any, major, and minor complications (all P values <.001). ASA demonstrated stronger model fit parameters for any, major and minor complications compared to all other indices, with an area under the curve of 0.63, 0.64, and 0.64, respectively (all P values <.001). Adding ASA to each frailty index resulted in slight improvement of model fit parameters (P value <.001).

ASA slightly outperforms current frailty indices in predicting postoperative complications among individuals undergoing commonly performed urologic procedures. Our findings highlight the need for improved frailty measures for preoperative risk assessment.