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

Peter G Passias; Katherine E Pierce; Jamshaid M Mir; Oscar Krol; Renaud Lafage; Virginie Lafage; Breton Line; Juan S Uribe; Richard Hostin; Alan Daniels; Robert Hart; Douglas Burton; Christopher Shaffrey; Frank Schwab; Bassel G Diebo; Christopher P Ames; Justin S Smith; Andrew J Schoenfeld; Shay Bess; Eric O Klineberg; International Spine Study Group

doi:10.1007/s43390-023-00808-5

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

Spine Deform. 2024 May;12(3):811-817. doi: 10.1007/s43390-023-00808-5. Epub 2024 Feb 2.

Authors

Peter G Passias¹, Katherine E Pierce², Jamshaid M Mir², Oscar Krol², Renaud Lafage³, Virginie Lafage³, Breton Line⁴, Juan S Uribe⁵, Richard Hostin⁶, Alan Daniels⁷, Robert Hart⁸, Douglas Burton⁹, Christopher Shaffrey¹⁰, Frank Schwab¹¹, Bassel G Diebo⁷, Christopher P Ames¹², Justin S Smith¹³, Andrew J Schoenfeld¹⁴, Shay Bess⁴, Eric O Klineberg¹⁵; International Spine Study Group

Affiliations

¹ Division of Spinal Surgery, Departments of Orthopaedic and Neurological Surgery, NYU Langone Medical Center, Orthopaedic Hospital - NYU School of Medicine, New York Spine Institute, 301 East 17th St, New York, NY, 10003, USA. Peter.Passias@nyumc.org.
² Division of Spinal Surgery, Departments of Orthopaedic and Neurological Surgery, NYU Langone Medical Center, Orthopaedic Hospital - NYU School of Medicine, New York Spine Institute, 301 East 17th St, New York, NY, 10003, USA.
³ Department of Orthopaedic Surgery, Lenox Hill Hospital, Northwell Health, New York, NY, USA.
⁴ Department of Spine Surgery, Denver International Spine Clinic, Presbyterian St. Luke's/Rocky Mountain Hospital for Children, Denver, CO, USA.
⁵ Department of Neurosurgery, Barrow Neurological Institute, Phoenix, AZ, USA.
⁶ Department of Orthopaedic Surgery, Baylor Scoliosis Center, Dallas, TX, USA.
⁷ Department of Orthopaedic Surgery, Warren Alpert School of Medicine, Brown University, Providence, RI, USA.
⁸ Department of Orthopaedic Surgery, Swedish Neuroscience Institute, Seattle, WA, USA.
⁹ Department of Orthopaedic Surgery, University of Kansas Medical Center, Kansas City, KS, USA.
¹⁰ Department of Neurosurgery, Duke University, Durham, NC, USA.
¹¹ Department of Orthopedics, Hospital for Special Surgery, New York, NY, USA.
¹² Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA.
¹³ Department of Neurosurgery, University of Virginia, Charlottesville, VA, USA.
¹⁴ Department of Orthopedic Surgery, Brigham and Women's Center for Surgery and Public Health, Boston, MA, USA.
¹⁵ Department of Orthopaedic Surgery, University of California, Davis, Davis, CA, USA.

PMID: 38305990
DOI: 10.1007/s43390-023-00808-5

Abstract

Purpose: To develop a simplified, modified frailty index for adult spinal deformity (ASD) patients dependent on objective clinical factors.

Methods: ASD patients with baseline (BL) and 2-year (2Y) follow-up were included. Factors with the largest R² value derived from multivariate forward stepwise regression 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 (LOS, > 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 clin-ASD-FI with ASD-FI scores and published cutoffs 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.

Results: Five hundred thirty-one ASD patients (59.5 yrs, 79.5% F) were included. The final model had a R² of 0.681, and significant factors were: < 18.5 or > 30 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 < 0.001). Frailty independently predicted occurrence of any complication (OR: 9.357 [2.20-39.76], P = 0.002) and reop (OR: 2.79 [0.662-11.72], P = 0.162).

Conclusions: Utilizing an existing ASD frailty index, we proposed a modified version eliminating the patient-reported components. This index is a true assessment of physiologic status, and represents a superior risk factor assessment compared to other tools for both primary and revision spinal deformity surgery as a result of its immutability with surgery, lack of subjectivity, and ease of use.

Keywords: Adult spinal deformity; Chronologic age; Frailty; Health-related quality of life; Physiologic age; Regression analysis.

MeSH terms

Adult
Aged
Female
Frailty* / complications
Humans
Length of Stay / statistics & numerical data
Male
Middle Aged
Postoperative Complications / epidemiology
Postoperative Complications / etiology
Risk Assessment / methods
Spinal Curvatures / surgery