Physical functioning in the lumbar spinal surgery population: A systematic review and narrative synthesis of outcome measures and measurement properties of the physical measures.

BACKGROUND

International agreement supports physical functioning as a key domain to measure interventions effectiveness for low back pain. Patient reported outcome measures (PROMs) are commonly used in the lumbar spinal surgery population but physical functioning is multidimensional and necessitates evaluation also with physical measures.

OBJECTIVE

1. To identify outcome measures (PROMs and physical) used to evaluate physical functioning in the lumbar spinal surgery population. 2) To assess measurement properties and describe the feasibility and interpretability of physical measures of physical functioning in this population.

STUDY DESIGN

Two-staged systematic review and narrative synthesis.

METHODS

This systematic review was conducted according to a registered and published protocol. Two stages of searching were conducted in MEDLINE, EMBASE, Health & Psychosocial Instruments, CINAHL, Web of Science, PEDro and ProQuest Dissertations & Theses. Stage one included studies to identify physical functioning outcome measures (PROMs and physical) in the lumbar spinal surgery population. Stage two (inception to 10 July 2023) included studies assessing measurement properties of stage one physical measures. Two independent reviewers determined study eligibility, extracted data and assessed risk of bias (RoB) according to COSMIN guidelines. Measurement properties were rated according to COSMIN criteria. Level of evidence was determined using a modified GRADE approach.

RESULTS

Stage one included 1,101 reports using PROMs (n = 70 established in literature, n = 67 developed by study authors) and physical measures (n = 134). Stage two included 43 articles assessing measurement properties of 34 physical measures. Moderate-level evidence supported sufficient responsiveness of 1-minute stair climb and 50-foot walk tests, insufficient responsiveness of 5-minute walk and sufficient reliability of distance walked during the 6-minute walk. Very low/low-level evidence limits further understanding.

CONCLUSIONS

Many physical measures of physical functioning are used in lumbar spinal surgery populations. Few have investigations of measurement properties. Strongest evidence supports responsiveness of 1-minute stair climb and 50-foot walk tests and reliability of distance walked during the 6-minute walk. Further recommendations cannot be made because of very low/low-level evidence. Results highlight promise for a range of measures, but prospective, low RoB studies are required.