Validation of the LOCOMO-25 and its minimum clinically important differences in domain scores for Chinese patients with low back pain and neck pain.

BACKGROUND

The 25-question Geriatric Locomotive Function Scale (LOCOMO-25) was developed to assess any decline in mobility functions. This study aims to validate the LOCOMO-25 in Chinese patients with chronic low back pain and/or neck pain.

METHODS

Adult patients with chronic low back pain and/or neck pain completed the LOCOMO-25, SF-36, EQ-5D-5L, ODI, VAS and/or NDI. Internal consistency was assessed by Cronbach's alpha coefficient (α). Test-retest reliability was assessed by intra-class correlation coefficients. Construct validity was assessed by Spearman correlation tests against other outcome measures. Sensitivity to detect differences between groups was assessed by Mann-Whitney U or Kruskal-Wallis H test, where appropriate. Intergroup comparison was performed further in terms of domain scores and their changes at test-retest.

RESULTS

A total of 111 patients were consecutively recruited. LOCOMO-25 demonstrated excellent internal consistency (α = 0.915) and test-retest reliability (Intraclass correlation: 0.705 to 0.826). LOCOMO-25 was significantly correlated with all domains of SF-36, EQ-5D, ODI, NDI, and VAS (p < 0.01). It was found to be sensitive in differentiating between patients with neural compression (32.8 ± 16.9) and without (21.2 ± 12.7), with history of fall(s) within the previous one year (30.8 ± 16.0) and without (24.2 ± 15.1), requires assistive devices for ambulation (40.6 ± 21.6) or independent (23.6 ± 13.1) and various pain levels (mild: 17.2 ± 10.6; moderate: 23.5 ± 11.7; severe: 38.5 ± 16.5). Patients with neural compression scored significantly higher in the domain of pain and patients requiring assistive devices for ambulation scored significantly higher in the domains of ADL and social functions. The minimum detectable differences for various domains of the LOCOMO-25 score included pain (2.76), activities of daily living (6.07), social function (1.59), and mental health status (2.06).

CONCLUSIONS

LOCOMO-25 has been validated in Chinese patients with chronic low back and neck pain with satisfactory psychometric properties, and with individual domain minimum clinically important differences. There is adequate internal consistency, test-retest reliability, construct validity and sensitivity to detect differences between patients with/without neural compression, different ambulatory statuses and pain severity.