Psychometric properties of the 30-m walking test in patients with degenerative cervical myelopathy: results from two prospective multicenter cohort studies.
Study Goal
The researchers aimed to evaluate the test-retest reliability, validity, and responsiveness to change of the 30-meter walking test (30MWT) in patients with degenerative cervical myelopathy (DCM).
Results Summary
The 30MWT demonstrated high test-retest reliability and good convergent and divergent validity but was only responsive to change in patients with more severe myelopathy. The test is simple, quick, and affordable, suitable as an ancillary gait evaluation tool for DCM patients.
Population
Patients with symptomatic degenerative cervical myelopathy (DCM) enrolled in multicenter studies.
Effective Dosage
Not applicable (walking test, not a supplement).
Duration
Evaluated at baseline and 6 months postoperatively.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
30-m walking test (30MWT) | increase | test-retest reliability | patients with degenerative cervical myelopathy (DCM) | high | shows high test-retest reliability | #1 |
30-m walking test (30MWT) | increase | convergent and divergent validity | patients with degenerative cervical myelopathy (DCM) | good | demonstrated good convergent and divergent validity | #2 |
30-m walking test (30MWT) | increase | Nurick scale | patients with degenerative cervical myelopathy (DCM) | r=0.4932 | was moderately correlated with | #3 |
30-m walking test (30MWT) | decrease | modified Japanese Orthopaedic Association scale (mJOA) | patients with degenerative cervical myelopathy (DCM) | r=-0.4424 | was moderately correlated with | #4 |
30-m walking test (30MWT) | decrease | Short-Form-36 (SF-36v2) physical component score (PCS) | patients with degenerative cervical myelopathy (DCM) | r=-0.3537 | was moderately correlated with | #5 |
30-m walking test (30MWT) | increase | Neck Disability Index (NDI) | patients with degenerative cervical myelopathy (DCM) | r=0.2107 | was poorly correlated with | #6 |
30-m walking test (30MWT) | decrease | Short-Form-36 (SF-36v2) mental component score (MCS) | patients with degenerative cervical myelopathy (DCM) | r=-0.1984 | was poorly correlated with | #7 |
30-m walking test (30MWT) | no change | responsiveness to change | patients with degenerative cervical myelopathy (DCM) | standardized response mean (SRM)=0.30 | was not responsive to change | #8 |
30-m walking test (30MWT) | increase | responsiveness to change | patients with more severe myelopathy | standardized response mean (SRM)=0.45 | is responsive to change | #9 |
BACKGROUND CONTEXT: The timed 30-m walking test (30MWT) is used in clinical practice and in research to objectively quantify gait impairment. The psychometric properties of 30MWT have not yet been rigorously evaluated. PURPOSE: This study aimed to determine test-retest reliability, divergent and convergent validity, and responsiveness to change of the 30MWT in patients with degenerative cervical myelopathy (DCM). STUDY DESIGN/SETTING: A retrospective observational study was carried out. PATIENT SAMPLE: The sample consisted of patients with symptomatic DCM enrolled in the AOSpine North America or AOSpine International cervical spondylotic myelopathy studies at 26 sites. OUTCOME MEASURES: Modified Japanese Orthopaedic Association scale (mJOA), Nurick scale, 30MWT, Neck Disability Index (NDI), and Short-Form-36 (SF-36v2) physical component score (PCS) and mental component score (MCS) were the outcome measures. METHODS: Data from two prospective multicenter cohort myelopathy studies were merged. Each patient was evaluated at baseline and 6 months postoperatively. RESULTS: Of 757 total patients, 682 (90.09%) attempted to perform the 30MWT at baseline. Of these 682 patients, 602 (88.12%) performed the 30MWT at baseline. One patient was excluded, leaving601 in the analysis. At baseline, 81 of 682 (11.88%) patients were unable to perform the test, and their mJOA, NDI, and SF-36v2 PCS scores were lower compared with those who performed the test at baseline. In patients who performed the 30MWT at baseline, there was very high correlation among the three baseline 30MWT measurements (r=0.9569-0.9919). The 30MWT demonstrated good convergent and divergent validity. It was moderately correlated with the Nurick (r=0.4932), mJOA (r=-0.4424), and SF-36v2 PCS (r=-0.3537) (convergent validity) and poorly correlated with the NDI (r=0.2107) and SF-36v2 MCS (r=-0.1984) (divergent validity). Overall, the 30MWT was not responsive to change (standardized response mean [SRM]=0.30). However, for patients who had a baseline time above the median value of 29 seconds, the SRM was 0.45. CONCLUSIONS: The 30MWT shows high test-retest reliability and good divergent and convergent validity. It is responsive to change only in patients with more severe myelopathy. The 30MWT is a simple, quick, and affordable test, and should be used as an ancillary test to evaluate gait parameters in patients with DCM.