Any infection among patients with hip fracture: Predictive ability of Charlson, Elixhauser, Rx-Risk, and Nordic comorbidity indices.

Background: In studies on infection after hip fracture surgery, a common and serious complication, it remains unknown which comorbidity index is best for case-mix confounder adjustment. We evaluated the predictive ability of Charlson Comorbidity Index (CCI), Elixhauser Comorbidity Index (ECI), Rx-Risk Index (Rx-Risk), and Nordic Multimorbidity Index (NMI) for any infection up to 1 year from discharge after hip fracture surgery.

Methods: Using Danish medical registries, we included 92,600 patients (mean age 83 years) surgically treated for hip fracture between 2004 and 2018.