External validation of the smartphone-based 6-minute walking test in patients with degenerative lumbar disorders undergoing epidural steroid injection

Michal Ziga, MD; Martin N. Stienen, MD/FEBNS; Anna Maria Zeitlberger, MD; Stefanos Voglis, MD; Luca Regli, MD; Oliver Bozinov, MD; Nicolai Maldaner, MD

North American Spine Society Journal (Dec 2024)

External validation of the smartphone-based 6-minute walking test in patients with degenerative lumbar disorders undergoing epidural steroid injection

Michal Ziga, MD,
Martin N. Stienen, MD/FEBNS,
Anna Maria Zeitlberger, MD,
Stefanos Voglis, MD,
Luca Regli, MD,
Oliver Bozinov, MD,
Nicolai Maldaner, MD

Affiliations

Michal Ziga, MD: Department of Neurosurgery, Kantonsspital St. Gallen & Medical School of St.Gallen, St. Gallen, Switzerland; First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic; Spine Center of Eastern Switzerland, Kantonsspital St. Gallen & Medical School of St.Gallen, St. Gallen, Switzerland; Department of Neurosurgery and Spine Surgery, Luzerner Kantonsspital and University of Lucerne, Lucerne, Switzerland
Martin N. Stienen, MD/FEBNS: Department of Neurosurgery, Kantonsspital St. Gallen & Medical School of St.Gallen, St. Gallen, Switzerland; Spine Center of Eastern Switzerland, Kantonsspital St. Gallen & Medical School of St.Gallen, St. Gallen, Switzerland
Anna Maria Zeitlberger, MD: Department of Neurosurgery, Kantonsspital St. Gallen & Medical School of St.Gallen, St. Gallen, Switzerland; Spine Center of Eastern Switzerland, Kantonsspital St. Gallen & Medical School of St.Gallen, St. Gallen, Switzerland
Stefanos Voglis, MD: Department of Neurosurgery, University Hospital Zurich & Clinical Neuroscience Centre, University of Zurich, Zurich, Switzerland
Luca Regli, MD: Department of Neurosurgery, University Hospital Zurich & Clinical Neuroscience Centre, University of Zurich, Zurich, Switzerland
Oliver Bozinov, MD: Department of Neurosurgery, Kantonsspital St. Gallen & Medical School of St.Gallen, St. Gallen, Switzerland; Department of Neurosurgery, University Hospital Zurich & Clinical Neuroscience Centre, University of Zurich, Zurich, Switzerland
Nicolai Maldaner, MD: Department of Neurosurgery, University Hospital Zurich & Clinical Neuroscience Centre, University of Zurich, Zurich, Switzerland; Corresponding author. Department of Neurosurgery, University Hospital Zurich, Clinical Neuroscience Center, University of Zurich, Frauenklinikstrasse 10, Zurich 8091, Switzerland.

Journal volume & issue: Vol. 20
p. 100561

Abstract

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Background: The 6-minute walking test (6WT) has previously shown to be reliable and valid outcome measure in patients undergoing surgery for degenerative lumbar disorders (DLD). A role of 6WT in conservatively treated patients undergoing epidural steroid injection (ESI) remains unclear. Methods: About 50 patients with DLD, scheduled for ESI were assessed by the smartphone-based 6WT and common paper-based patient-reported outcome measures (PROMs), including the Core Outcome Measures Index [COMI] back, Oswestry Disability Index (ODI) and Short Form Survey (SF-12). Pearson correlation coefficient (PCC) was used to define the relationship between 6WT and PROMs. Reliability of the 6WT was determined by intraclass correlation coefficient (ICC). Age- and sex-adjusted objective functional impairment (OFI) z-scores were calculated for each patient. Results: A total of 50 patients (mean age 52 years, SD 13; 25% female), including 35 patients (70%) with lumbar disc herniation and 15 patients (30%) with lumbar spinal stenosis were included. The mean 6-minute walking distance (6WD) was 454.1 m (SD 89.1); the age- and sex-adjusted mean OFI z-score was −2.1 (SD 4.0). A total of 17 (34%) patients had mild, 8 (16%) moderate, and 4 (8%) severe OFI, while 21 (42%) had 6WT results within the normal population range (no OFI). The PCCs between the 6WD and VAS back pain were r=−0.30, ODI r=−0.43, COMI back r=−0.36, and PCS-12 r=0.51 (all p<.05). The ICC of the 6WT was β=0.92. Conclusions: This external validation in a patient cohort with DLD, which was managed conservatively, confirms the reliability and content validity of the 6WT with similar PCCs with PROMs compared to the original surgical cohort. The results confirm the 6WT as a valid and useful tool for assessing OFI in patients with DLD and a broad range of functional restrictions in an outpatient setting.

Published in North American Spine Society Journal

ISSN: 2666-5484 (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Medicine: Surgery: Orthopedic surgery; Medicine: Internal medicine: Neurosciences. Biological psychiatry. Neuropsychiatry: Neurology. Diseases of the nervous system
Website: https://www.journals.elsevier.com/north-american-spine-society-journal-nassj/

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