Copenhagen Neck Functional Disability Scale (CNFDS)

The Copenhagen Neck Functional Disability Scale (CNFDS) is a self-administered questionnaire developed to measure functional limitations in patients with neck pain. The scale was created by Jordan et al. in 1998 and is partly based on the Neck Disability Index (NDI) and the Low Back Pain Rating Scale¹.

Target Group

CNFDS was designed to improve the generalizability of the Neck Disability Index in European populations⁷. It is used for patients with:

• Chronic neck pain

• Cervical disc herniation

• Mechanical neck pain

• Patients undergoing physiotherapy³

The test has been validated for patients aged 20 to 75 years⁷.

Method

The scale consists of 15 questions, with three possible answers:

• “Yes,” “Sometimes,” or “No.”

Scoring is structured as follows:

• Items 1–5: “Yes” = good function

• Items 6–15: “No” = good function

Point allocation:

• 0 points = good function

• 1 point = moderate function

• 2 points = poor function

Total score:

• 0 = no neck disability

• 30 = maximum functional disability³

Scores can be compared as raw scores or expressed as percentage change from baseline³.

Validity and Reliability

Reliability

• Test–retest reliability:

  • Same day: Pearson r = 0.99

  • Two days later: Pearson r = 0.98

• Internal consistency: Cronbach’s α = 0.90, indicating excellent reliability³,⁷.

Validity

• Construct validity: Measures functional limitations due to neck pain³.

• Comparison with patient self-rating: Spearman r = 0.89 (high)³.

• Comparison with physician rating: Spearman r = 0.56 (moderate)³,⁷.

• Correlation with VAS pain scores:

  • CNFDS and current pain: r = 0.45

  • CNFDS and worst pain: r = 0.37

  • CNFDS and average pain: r = 0.19⁸.

Responsiveness

• Responsiveness to the NDI, Northwick Park Pain Questionnaire, and Neck Pain and Disability Scale is nearly identical (SRM = 0.89, p < 0.01)⁴.

• Correlation with pain scores over time:

  • 6 weeks: r = 0.49, p < 0.0001

  • 4 months: r = 0.48, p < 0.0001

  • 12 months: r = 0.54, p < 0.0001³,⁷,⁹.

Other Factors

• No floor or ceiling effects observed⁶,⁵.

• No gender or age differences in scoring³.

• No established minimal clinically important difference (MCID) reported⁷.

Conclusion

The CNFDS is a reliable and validated tool for assessing functional disability in patients with neck pain. It is simple to administer, takes about 10 minutes, and can be delivered via paper, mail, or telephone. The questionnaire demonstrates high test–retest reliability and strong agreement with patients’ self-perceived disability.

Kilder:

1. FEJER, R., JORDAN, A. & HARTVIGSEN, J. 2005. Categorising the severity of neck pain: establishment of cut-points for use in clinical and epidemiological research. Pain, 119, 176-82.

2. PICKERING, P. M., OSMOTHERLY, P. G., ATTIA, J. R. & MCELDUFF, P. 2011. An examination of outcome measures for pain and dysfunction in the cervical spine: a factor analysis. Spine (Phila Pa 1976), 36, 581-8. (level of evidence 2C)

3. JORDAN, A., MANNICHE, C., MOSDAL, C. & HINDSBERGER, C. 1998. The Copenhagen Neck Functional Disability Scale: a study of reliability and validity. J Manipulative Physiol Ther, 21, 520-7.

4. KOSE, G., HEPGULER, S., ATAMAZ, F. & ODER, G. 2007. A comparison of four disability scales for Turkish patients with neck pain. J Rehabil Med, 39, 358-62.

5. SCHELLINGERHOUT, J. M., VERHAGEN, A. P., HEYMANS, M. W., KOES, B. W., DE VET, H. C. & TERWEE, C. B. 2012. Measurement properties of disease-specific questionnaires in patients with neck pain: a systematic review. Qual Life Res, 21, 659-70.

6. MISTERSKA, E., JANKOWSKI, R. & GLOWACKI, M. 2011. Cross-cultural adaptation of the Neck Disability Index and Copenhagen Neck Functional Disability Scale for patients with neck pain due to degenerative and discopathic disorders. Psychometric properties of the Polish versions. BMC Musculoskelet Disord, 12, 84. .

7. PIETROBON, R., COEYTAUX, R. R., CAREY, T. S., RICHARDSON, W. J. & DEVELLIS, R. F. 2002. Standard scales for measurement of functional outcome for cervical pain or dysfunction: a systematic review. Spine (Phila Pa 1976), 27, 515-22.

8. FORESTIER, R., FRANCON, A., ARROMAN, F. S. & BERTOLINO, C. 2007. French version of the Copenhagen neck functional disability scale. Joint Bone Spine, 74, 155-9.

9. FERREIRA, M. L., BORGES, B. M., REZENDE, I. L., CARVALHO, L. P., SOARES, L. P., DABES, R. A., CARVALHO, G., DRUMMOND, A. S., MACHADO, G. C. & FERREIRA, P. H. 2010. Are neck pain scales and questionnaires compatible with the international classification of functioning, disability and health? A systematic review. Disabil Rehabil, 32, 1539-46.