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

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

Physical functioning outcome measures in the lumbar spinal surgery population and measurement properties of the physical outcome measures: protocol for a systematic review

“…For example, preoperative and early postoperative physical outcome measures of physical functioning predict good outcome following lumbar spinal surgery. 23 32 33 Early identification of deficits in physical outcome measures will enable targeted rehabilitation interventions to improve patient outcomes following lumbar spinal surgery. Use of physical outcome measures also aligns with recently updated physical therapy clinical practice guidelines for the management of acute and chronic low back pain.…”

“… 5 6 Further highlighting the importance of physical outcome measures, studies suggest good outcome after lumbar spinal surgery is associated with preoperative and postoperative physical outcome measures of physical functioning. 23 31–33 …”

“…However, given the multidimensional nature of physical functioning, content validity of the ODI and other physical functioning PROMs is lacking in the lumbar spinal pain population 17 22. This is also suggested in the lumbar spinal surgery population as PROMs do not provide a comprehensive evaluation of physical functioning 5 6 23. Further, a range of contextual factors can influence a patient’s perspective of their physical functioning, such as pain and psychological functioning,10 24 25 limiting the responsiveness and interpretability of PROMs 26 27.…”

“…Compared with PROMs, physical outcome measures evaluate distinct aspects of physical functioning, and when used in combination, provide a comprehensive evaluation of physical functioning 5 6 10 15 23 24. International recommendations in other surgical disciplines (eg, hip and knee arthroplasty) are to measure both PROMs and physical outcomes in evaluations of physical functioning 28 29.…”

“…For example, after lumbar spinal surgery the trajectory of recovery differs between PROMs and physical outcome measures as there is a rapid improvement in ODI scores with slower improvement in Timed Up and Go performance and accelerometry measures of daily activity 5 6. Further highlighting the importance of physical outcome measures, studies suggest good outcome after lumbar spinal surgery is associated with preoperative and postoperative physical outcome measures of physical functioning 23 31–33…”