210. Development of a modified frailty index for adult spinal deformities independent of functional changes following surgical correction: a true baseline risk assessment tool

• Published in: The spine journal 2020-09, Vol.20 (9), p.S103-S104
• Main Authors: Passias, Peter G., Pierce, Katherine E., Lafage, Virginie, Lafage, Renaud, Line, Breton, Hamilton, D. Kojo, Uribe, Juan S., Hostin, Richard A., Daniels, Alan H., Hart, Robert A., Burton, Douglas C., Shaffrey, Christopher I., Schwab, Frank J., Ames, Christopher P., Smith, Justin S., Bess, Shay, Klineberg, Eric O., International Spine Study Group
• Format: Article
• Language: English
• ISSN: 1529-9430; 1878-1632
• DOI: 10.1016/j.spinee.2020.05.621

The Miller et al. adult spinal deformity frailty index (ASD-FI) correlates with increased complication risk after surgery; however, its development is rooted in health related quality of life metrics (HRQLs) that may be subjective, and the 40 factors needed for its calculation limit the index's utility in a clinical setting. Develop a simplified, modified frailty index for ASD patients Retrospective cohort study A total of 531 ASD patients HRQLs, length of stay (LOS) ASD patients (scoliosis≥20°, SVA≥5cm, PT≥25°, or TK ≥60°) with baseline (BL) and 2-year HRQL follow up. HRQL components were removed from the FI and top contributors to the ASD-FI score of the remaining were assessed via Pearson correlation, and included in forward multiple stepwise regressions. Factors with the largest R2 value were including in the modified, ASD-FI (clin-ASD-FI). Factors included in the clin-ASD-FI were regressed against mortality, extended length of hospital stay (>8 days), revisions, major complications and weights for the clin-ASD-FI were calculated via Beta/Sullivan. Total clin-ASD-FI score was created with a score from 0 to 1. Linear regression correlated the clin-ASD-FI with ASD-FI scores and published cut-offs for the ASD-FI were used to create the new frailty cutoffs: not frail (NF: < 0.11), frail (F: 0.11-0.21) and severely frail (SF: >0.21). Binary logistic regression assessed odds of complication or reop for frail patients. Logistic regressions were run to determine whether the clin-ASD-FI is superior to previously utilized measures predicting risk (age, ASA, previous FI, and CCI) for complications and reop. A total of 531 ASD patients (59.5yrs, 79.5%F). The final stepwise regression model R2 of 0.681: 20 BMI (weight: 0.0625 out of 1), cardiac disease (0.125), disability employment status (0.3125), diabetes mellitus (0.0625), hypertension (0.0625), osteoporosis (0.125), blood clot (0.1875), and bowel incontinence (0.0625). These factors calculated the score from 0 to 1, with a mean cohort score of 0.13±0.14. Breakdown by clin-ASD-FI score: 51.8% NF, 28.1% F, 20.2% SF. Increasing frailty severity was associated with longer LOS (NF: 7.0, F: 8.3, SF: 9.2 days; p