Probability of severe frailty development among operative and nonoperative adult spinal deformity patients: an actuarial survivorship analysis over a 3-year period

Little is known of how frailty, a dynamic measure of physiological age, progresses relative to age or disability status. Operative treatment of adult spinal deformity (ASD) may play a role in frailty remediation and maintenance. Compare frailty status, severe frailty development, and factors influencing severe frailty development among ASD patients undergoing operative or nonoperative treatment. Retrospective review with maximum follow-up of 3 years. Prospective, multicenter, ASD database. Patients were consecutively enrolled from 13 participating centers. Inclusion criteria: ≥18 years undergoing either operative or nonoperative treatment for ASD, exclusion criteria: spinal deformity of neuromuscular etiology, presence of active infection, or malignancy. The mean age of the participants analyzed were 54.9 for the operative cohort and 55.0 for the nonoperative cohort. Frailty status, severe frailty development, and factors influencing severe frailty development. ASD patients (coronal scoliosis ≥20°, sagittal vertical axis (SVA) ≥5 cm, Pelvic Tilt (PT) ≥25°, or thoracic kyphosis ≥60°) >18 y/o, with Base Line (BL) frailty scores were included. Frailty was scored from 0 to 1 (not frail: 0.5) through the use of ASD-frailty index (FI) which has been validated using the International Spine Study Group (ISSG) ASD database, European Spine Study Group ASD database, and the Scoli-RISK-1 Patient Database. The ISSG is funded through research grants from DePuy Synthes and individual donations and supported the current work. Operative (Op) and Nonoperative (Non-Op) patients were propensity matched. T-tests compared frailty among treatment groups and BL, 1, 2, and ≥3 years. An actuarial Kaplan-Meier survivorship analysis with log-rank (Mantel-Cox) test, adjusting for patients lost to follow-up, determined probability of severe frailty development. Multivariate Cox Regressions gauged the effect of sagittal malalignment, patient and surgical details on severe frailty development. The analysis includes 472 patients (236 Op, 236 Non-Op) selected by propensity score matching from a cohort of 1,172. Demographics and comorbidities were similar between groups (p>.05). Op exhibited decreased frailty at all follow-up intervals compared with BL (BL: 0.22 vs Y1: 0.18; Y2: 0.16; Y3: 0.15, all p