Physical Performance Tests Provide Distinct Information in Both Predicting and Assessing Patient-Reported Outcomes Following Lumbar Spine Surgery

Hiral Master, PT, PhD, MPH; Jacquelyn S. Pennings, PhD; Rogelio A. Coronado, PT, PhD; Abigail L. Henry, MPH; Michael T. O'Brien; Christine M. Haug, MPH; Richard L. Skolasky, ScD; Lee H. Riley III, MD; Brian J. Neuman, MD; Joseph S. Cheng, MD; Oran S. Aaronson, MD; Clinton J. Devin, MD; Stephen T. Wegener, PhD; Kristin R. Archer, PhD, DPT

Disclosures

Spine. 2020;45(23):E1556-E1563. 

In This Article

Abstract and Introduction

Abstract

Study Design: Secondary analysis of randomized controlled trial data.

Objective: The aim of this study was to examine whether preoperative physical performance is an independent predictor of patient-reported disability and pain at 12 months after lumbar spine surgery.

Summary of Background Data: Patient-reported outcome measures (PROMs) are commonly used to assess clinical improvement after lumbar spine surgery. However, there is evidence in the orthopedic literature to suggest that PROMs should be supplemented with physical performance tests to accurately evaluate long-term outcomes.

Methods: A total of 248 patients undergoing surgery for degenerative lumbar spine conditions were recruited from two institutions. Physical performance tests (5-Chair Stand and Timed Up and Go) and PROMs of disability (Oswestry Disability Index: ODI) and back and leg pain (Brief Pain Inventory) were assessed preoperatively and at 12 months after surgery.

Results: Physical performance tests and PROMs significantly improved over 12 months following lumbar spine surgery (P < 0.01). Weak correlations were found between physical performance tests and disability and pain (ρ = 0.15 to 0.32, P < 0.05). Multivariable regression analyses controlling for age, education, preoperative outcome score, fusion, previous spine surgery, depressive symptoms, and randomization group found that preoperative 5-Chair Stand test was significantly associated with disability and back pain at 12-month follow-up. Each additional 10 seconds needed to complete the 5-Chair Stand test were associated with six-point increase in ODI (P = 0.047) and one-point increase in back pain (P = 0.028) scores. The physical performance tests identified an additional 14% to 19% of patients as achieving clinical improvement that were not captured by disability or pain questionnaires.

Conclusion: Results indicate that physical performance tests may provide distinct information in both predicting and assessing clinical outcomes in patients undergoing lumbar spine surgery. Our findings suggest that the 5-Chair Stand test may be a useful test to include within a comprehensive risk assessment before surgery and as an outcome measure at long-term follow-up.

Level of Evidence: 3

Introduction

Accurate measurement of preoperative and postoperative outcomes has become an essential aspect of orthopedic surgical care due to its relevance in value-based reimbursement and postoperative management.[1] In particular, patient-reported outcome measures (PROMs) for perceived health status have been integrated into clinical care as medicine has become more patient-centered.[2] Common PROMs in spine surgery include the Oswestry/Neck Disability Index, Numeric Rating Scales for axial and extremity pain, Japanese Orthopaedic Association Outcome Questionnaire, and Short-Form Health Survey (SF-36).[3,4] PROMs in spine surgery have demonstrated responsiveness, the ability to predict long-term patient satisfaction, and the capacity to identify patients who will respond to surgical intervention.[5,6] However, there is a growing body of evidence in the orthopedic literature that suggests PROMs should be supplemented with objective physical performance tests to accurately evaluate long-term outcomes.[7–9]

Previous studies in the total joint population have found that PROMs and physical performance tests measure different constructs, and physical performance tests provide unique and relevant information on patient response to treatment.[10–13] To date, the literature on physical performance tests in patients undergoing spine surgery is limited. Preliminary data have found that objective physical performance test scores, such as gait speed and ambulation distance, improve up to 6 months after spine surgery.[14,15] However, additional studies are needed to better understand whether integrating physical performance tests into clinical practice can improve the assessment and management of patients undergoing spine surgery.

In this study, the primary aim was to determine whether objective physical performance tests are significant predictors of disability and pain at 1 year following lumbar spine surgery. We hypothesized that preoperative tests of strength and mobility, 5-Chair Stand and Timed Up and Go (TUG), would be significantly associated with disability and pain. An additional objective was to examine the relationship between physical performance tests and PROMs of disability and pain at the preoperative and 12-month follow-up timepoints. Results will help determine whether physical performance tests provide added value to surgeons by providing a greater understanding of their patients' baseline functional status and postoperative recovery.

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