The Neck Disability Index-Russian Language Version (NDI-RU): A Study of Validity and Reliability.

STUDY DESIGN: Cross-cultural adaptation and psychometric testing. OBJECTIVE: To perform a validated Russian translation and then to evaluate the validity and reliability of the Russian language version of the Neck Disability Index (NDI-RU). SUMMARY OF BACKGROUND DATA: Neck pain is highly prevalent and can greatly affect daily activity. The Neck Disability Index (NDI) is the most frequently used scale for self-rating of disability due to neck pain. Its translated versions are applied in many countries. However, the Russian language version of the NDI has not been developed yet. METHODS: Cross-cultural adaptation of the NDI-RU was performed according to established guidelines. Then, the NDI-RU was evaluated for content validity, concurrent criterion validity, internal consistency, test-retest reliability, factor structure, and minimum detectable change. RESULTS: Two hundred thirty-two patients took part in the study in total: 109 in validity (39.5 ± 10 yr), 123 in reliability (38.4 ± 11 yr; 80 in the test-retest phase). A culturally valid translation was achieved. NDI-RU total scores were distributed normally. Floor/ceiling effects were absent. Good values of Cronbach α were obtained for each item (from 0.80 to 0.84) and for the total NDI-RU (0.83). A 2-factor solution was found for the NDI-RU. The average interitem correlation coefficient was 0.53. Intraclass correlation coefficients for test-retest reliability coefficients ranged from 0.65 to 0.92 for different items and 0.91 for the total NDI-RU. Moderate correlation (Spearman rs = 0.62; P < 0.05) was found between the NDI-RU total score and graphic rating scalepain score. Completion of the NDI-RU takes 3.6 ± 1 minutes. CONCLUSION: The development of a Russian language version of the Neck Disability Index resulted in a valid, reliable instrument that can be used both in clinical practice and scientific investigations. LEVEL OF EVIDENCE: 1.

Cerebral perfusion in patients with chronic neck and upper back pain: preliminary observations.

OBJECTIVE: The purpose of this study was to determine the correlation between cerebral perfusion levels, Neck Disability Index (NDI) scores, and spinal joint fixations in patients with neck pain. METHODS: Forty-five adult patients (29 were female) with chronic neck/upper thoracic pain during exacerbation were studied. The subjects were grouped according to NDI scores: mild, moderate, and severe. The number of painful/blocked segments in the cervical and upper thoracic spine and costovertebral joints, pain intensity using the visual analog scale, and regional cerebral blood flow of the brain using single-photon emission computed tomography (SPECT) were obtained. The SPECT was analyzed semiquantitatively. Analysis of variance tests were conducted on total SPECT scores in each of the NDI groups (P < .05). Univariate correlations were obtained between blockage, pain, and SPECT scores, as well as age and duration. A multivariate analysis was then conducted. RESULTS: Group 1 (mild) consisted of 14 patients. Cerebral perfusion measured by SPECT was normal in all 8 brain regions. Group 2 (moderate) consisted of 16 patients. In this group, a decrease in cerebral perfusion was observed (range, 20%-35%), predominantly in the parietal and frontal zones. Group 3 (severe) consisted of 15 patients. In this group, the decrease in cerebral perfusion observed was from 30% to 45%, again predominantly in the parietal and frontal zones. A significant difference was found between NDI groups ("moderate" and "severe" showed significantly greater hypoperfusion than "mild"). Total blockage score correlated with SPECT scores at r = 0.47, P = .001. In a multivariate analysis, NDI scores contributed 39% of the variance of SPECT scores. CONCLUSION: In this group of patients with neck and/or upper back pain, NDI scores strongly predicted cerebral hypoperfusion. Spinal joint dysfunction may be involved via hyperactivity in the regional sympathetic nervous system.