TY - JOUR
T1 - Development and validation of risk stratification models for adult spinal deformity surgery
AU - International Spine Study Group
AU - European Spine Study Group
AU - Pellisé, Ferran
AU - Serra-Burriel, Miquel
AU - Smith, Justin S.
AU - Haddad, Sleiman
AU - Kelly, Michael P.
AU - Vila-Casademunt, Alba
AU - Pérez-Grueso, Francisco Javier Sánchez
AU - Bess, Shay
AU - Gum, Jeffrey L.
AU - Burton, Douglas C.
AU - Acaroğlu, Emre
AU - Kleinstück, Frank
AU - Lafage, Virginie
AU - Obeid, Ibrahim
AU - Schwab, Frank
AU - Shaffrey, Christopher I.
AU - Alanay, Ahmet
AU - Ames, Christopher
N1 - Publisher Copyright:
©AANS 2019, except where prohibited by US copyright law.
PY - 2019/10
Y1 - 2019/10
N2 - OBJECTIVE Adult spinal deformity (ASD) surgery has a high rate of major complications (MCs). Public information about adverse outcomes is currently limited to registry average estimates. The object of this study was to assess the incidence of adverse events after ASD surgery, and to develop and validate a prognostic tool for the time-to-event risk of MC, hospital readmission (RA), and unplanned reoperation (RO). METHODS Two models per outcome, created with a random survival forest algorithm, were trained in an 80% random split and tested in the remaining 20%. Two independent prospective multicenter ASD databases, originating from the European continent and the United States, were queried, merged, and analyzed. ASD patients surgically treated by 57 surgeons at 23 sites in 5 countries in the period from 2008 to 2016 were included in the analysis. RESULTS The final sample consisted of 1612 ASD patients: mean (standard deviation) age 56.7 (17.4) years, 76.6% women, 10.4 (4.3) fused vertebral levels, 55.1% of patients with pelvic fixation, 2047.9 observation-years. Kaplan-Meier estimates showed that 12.1% of patients had at least one MC at 10 days after surgery; 21.5%, at 90 days; and 36%, at 2 years. Discrimination, measured as the concordance statistic, was up to 71.7% (95% CI 68%–75%) in the development sample for the postoperative complications model. Surgical invasiveness, age, magnitude of deformity, and frailty were the strongest predictors of MCs. Individual cumulative risk estimates at 2 years ranged from 3.9% to 74.1% for MCs, from 3.17% to 44.2% for RAs, and from 2.67% to 51.9% for ROs. CONCLUSIONS The creation of accurate prognostic models for the occurrence and timing of MCs, RAs, and ROs following ASD surgery is possible. The presented variability in patient risk profiles alongside the discrimination and calibration of the models highlights the potential benefits of obtaining time-to-event risk estimates for patients and clinicians.
AB - OBJECTIVE Adult spinal deformity (ASD) surgery has a high rate of major complications (MCs). Public information about adverse outcomes is currently limited to registry average estimates. The object of this study was to assess the incidence of adverse events after ASD surgery, and to develop and validate a prognostic tool for the time-to-event risk of MC, hospital readmission (RA), and unplanned reoperation (RO). METHODS Two models per outcome, created with a random survival forest algorithm, were trained in an 80% random split and tested in the remaining 20%. Two independent prospective multicenter ASD databases, originating from the European continent and the United States, were queried, merged, and analyzed. ASD patients surgically treated by 57 surgeons at 23 sites in 5 countries in the period from 2008 to 2016 were included in the analysis. RESULTS The final sample consisted of 1612 ASD patients: mean (standard deviation) age 56.7 (17.4) years, 76.6% women, 10.4 (4.3) fused vertebral levels, 55.1% of patients with pelvic fixation, 2047.9 observation-years. Kaplan-Meier estimates showed that 12.1% of patients had at least one MC at 10 days after surgery; 21.5%, at 90 days; and 36%, at 2 years. Discrimination, measured as the concordance statistic, was up to 71.7% (95% CI 68%–75%) in the development sample for the postoperative complications model. Surgical invasiveness, age, magnitude of deformity, and frailty were the strongest predictors of MCs. Individual cumulative risk estimates at 2 years ranged from 3.9% to 74.1% for MCs, from 3.17% to 44.2% for RAs, and from 2.67% to 51.9% for ROs. CONCLUSIONS The creation of accurate prognostic models for the occurrence and timing of MCs, RAs, and ROs following ASD surgery is possible. The presented variability in patient risk profiles alongside the discrimination and calibration of the models highlights the potential benefits of obtaining time-to-event risk estimates for patients and clinicians.
KW - Adult spinal deformity surgery
KW - Prognostic models
KW - Risk stratification
UR - https://www.scopus.com/pages/publications/85072776080
U2 - 10.3171/2019.3.SPINE181452
DO - 10.3171/2019.3.SPINE181452
M3 - Article
C2 - 31252385
AN - SCOPUS:85072776080
SN - 1547-5654
VL - 31
SP - 587
EP - 599
JO - Journal of Neurosurgery: Spine
JF - Journal of Neurosurgery: Spine
IS - 4
ER -