Updated external validation of the SORG machine learning algorithms for prediction of ninety-day and one-year mortality after surgery for spinal metastasis.

Abstract Background Context Surgical decompression and stabilization in the setting of spinal metastasis is performed to relieve pain and preserve functional status. These potential benefits must be weighed against the risks of perioperative morbidity and mortality. Accurate prediction of a patient's post-operative survival is a crucial component of patient counseling. Purpose To externally validate the SORG machine learning algorithms for prediction of ninety-day and one-year mortality after surgery for spinal metastasis. Study Design/Setting Retrospective, cohort study Patient sample Patients 18 years or older at a tertiary care medical center treated surgically for spinal metastasis Outcome Measures mortality within ninety days of surgery, mortality within one year of surgery Methods This is a retrospective cohort study of 298 adult patients at a tertiary care medical center treated surgically for spinal metastasis between 2004 and 2020. Baseline characteristics of the validation cohort were compared to the derivation cohort for the SORG algorithms. The following metrics were used to assess the performance of the algorithms: discrimination, calibration, overall model performance, and decision curve analysis. Results Sixty-one patients died within ninety days of surgery and 133 died within one year of surgery. The validation cohort differed significantly from the derivation cohort. The SORG algorithms for ninety-day mortality and one-year mortality performed excellently with respect to discrimination; the algorithm for one-year mortality was well-calibrated. At both post-operative time points, the SORG algorithms showed greater net benefit than the default strategies of changing management for no patients or for all patients. Conclusions With an independent, contemporary, and geographically distinct population, we report successful external validation of SORG algorithms for pre-operative risk prediction of ninety-day and one-year mortality after surgery for spinal metastasis. By providing accurate prediction of intermediate and long-term mortality risk, these externally validated algorithms may inform shared decision-making with patients in determining management of spinal metastatic disease.