Spinal Surgery in Patients Aged 80 Years and Older: Risk Stratification Using the Modified Frailty Index

Barry Kweh; Hui Lee; Terence Tan; Tom O'Donohoe; Joseph Mathew; Mark Fitzgerald; Dashiell Gantner; Tony Kambourakis; Kim Tew; Martin Hunn; Jeffrey Rosenfeld; Jin Tee

doi:10.1177/2192568220914877

Spinal Surgery in Patients Aged 80 Years and Older: Risk Stratification Using the Modified Frailty Index

Global Spine J. 2021 May;11(4):525-532. doi: 10.1177/2192568220914877. Epub 2020 Mar 30.

Authors

Barry Kweh¹, Hui Lee^{1

2}, Terence Tan^{1

2}, Tom O'Donohoe¹, Joseph Mathew^{1

2}, Mark Fitzgerald^{1

2}, Dashiell Gantner^{2

3}, Tony Kambourakis², Kim Tew⁴, Martin Hunn^{2

3}, Jeffrey Rosenfeld^{2

3

5}, Jin Tee^{1

2

3}

Affiliations

¹ National Trauma Research Institute (NTRI), Melbourne, Australia.
² 5392Alfred Health, Melbourne, Australia.
³ Monash University, Melbourne, Australia.
⁴ 5644Peninsula Health, Melbourne, Australia.
⁵ Uniformed Services University of the Health Sciences, Bethesda, MD, USA.

Abstract

Study design: This was an ambispective clinical quality registry study.

Objective: To evaluate utility of 11-variable modified Frailty Index (mFI) in predicting postoperative outcomes among patients ≥80 years undergoing spinal surgery.

Methods: Consecutive patients ≥80 years who underwent spinal surgery between January 1, 2013, and June 30, 2018, were included. Primary outcome measure was rate of major complication. Secondary outcome measures were (1) overall complication rate, (2) surgical site infection, and (3) 6-month mortality.

Results: A total of 121 operations were performed. Demographic metrics were (1) age (mean ± SD) = 83.1 ± 2.8 years and (2) mFI (mean ± SD) = 2.1 ± 1.4 variables. As mFI increased from 0 to ≥4 variables, risk of major complication increased from 18.2% to 40.0% (P = .014); overall complication increased from 45.5% to 70.0% (P = .032); surgical site infection increased from 0.0% to 25.0% (P = .007). There were no significant changes in risk of 6-month mortality across mFIs (P = .115). Multivariate analysis showed that a higher mFI score of ≥3 variables was associated with a significantly higher risk of (1) major complication (P = .025); (2) overall complication (P = .015); (3) surgical site infection (P = .007); and (4) mortality (P = .044).

Conclusions: mFI scores of ≥3/11 variables were associated with a higher risk of postoperative morbidity in patients aged ≥80 years undergoing spinal surgery. The mFI-associated risk stratification provides a valuable adjunct in surgical decision making for this rapidly growing subpopulation of patients.

Keywords: elderly; frailty; infection; modified Frailty Index; mortality; postoperative complications; predictors; risk stratification; spinal surgery; spine trauma.