Copenhagen Neck Functional Disability Scale

Original Editor ­ Laura Vander Goten Top Contributors - Berdien De Koster, Laura Vander Goten, George Prudden and Oyemi Sillo ­ 



Objective

The Copenhagen Neck Functional Disability Scale (CNFDS) is a self-administered questionnaire developed to measure the level of functional disabilities in patients with neck pain. Jordan et al. designed this questionnaire in 1998. [1] It is partially derived from both the Neck Disability Index (NDI) and the Low Back Pain Rating Scale. [2]


The Copenhagen Neck Functional Disability Scale has been developed for those who have neck pain and disabilities due to the pain. The scale includes questions relating to headache, ability to sleep and to concentrate and activities of daily living. There are also questions of a psychosocial nature such as: social contact, emotional relationships and attitudes toward the future. [3]


This scale, together with the NDI, the Northwick Park Pain Questionnaire (NPPQ) and the Neck Pain and Disability Scale (NPDS) are widely used for assessing neck pain or disability. [4]


The scale’s original version was developed in Danish. [5][3] In the meanwhile there are several translations, such as in English, French, Turkish and Polish. All of them are validated and shown to be reliable. [4] [6] [3]

Intended Population

The CNFDS was especially devised to overcome the Neck Disability Index’s lack of generalizability to European populations. [7]


It was developed on people who had undergone neck surgery for cervical disc herniation, chronic neck pain and chronic mechanical neck pain. (Level of evidence: 2C) [3] The CNFDS is a useful instrument for patients with neck complaints treated by physiotherapy. The questionnaire is available for patient from 20 to 75 years. (Level of evidence: 2A) [7][3]

Method of Use

It’s a very easy questionnaire to take off and it can be completed in only 10 minutes. Patients can complete the scale by using pen and paper, mail or telephone. The instrument is useful in the clinical setting, and therefore often used in the practice. [7]


The CNFDS consists of 15 items. These items are individually answered by either ‘yes’, ‘occasionally’ or ‘no’. For questions one till five, a ‘yes’ indicates a good function. For questions six till fifteen, a ‘no’ indicates a good function. A good function receives a score of zero, a poor function receives a score of two and the answer ‘occasionally’ always receives a score of one. [1]


Afterwards, we add up all the scores of the questions to form the total score. This total score ranges from 0 to 30. [1] The total score determines the level of functional disability, in which higher numbers represent a higher level of disability. A score of 0 indicates that there are no neck complaints present whereas 30 indicates that the patient is extremely disabled as a result of the neck complaints. [3]


Comparison between repeated scores could be made between raw scores, or as percentage change from baseline (original) score. [3]


Evidence

Reliability

The reliability of the Copenhagen neck functional disability scale was evaluated with short-term (same day) and between-day (2 days later). Respectively the result was Pearson correlation coefficient of 0.99 and 0.98. Which means that the test-retest reliability is very good. (Grades of Recommendation: B) [7]


There is an extremely high internal consistency of the total scores, with a Cronbach alpha coefficient of 0.9. The individual items scored high alpha values uniformly. (Grades of Recommendation: B) [3]

Validity

Construct validity: Construct validity investigates whether the correct variables were measured in relation to the predefined variables. The Copenhagen neck functional disability scale measures the level of disabilities due to the pain. [3]


The construct validity of the English version was assessed by comparing disability scores to self-reported pain scores and to doctors and patients global assessment. The Pearson correlation for pain and disability is high (r = 0.83). The disability score compared with patients global assessment gave a Spearman rank correlation of r = 0.89, high score. The disability score compared with doctors global assessments gave a Spearman rank correlation of r = 0.56, a moderate score. (Grades of Recommendation: B) [3] [7]


External construct/convergent validity: There is a significantly correlation between the CNFDS and other numerical variables. (Grades of Recommendation: B) [8]

  • CNFDS and Vas-score for current pain: Spearman’s correlation = 0.45
  • CNFDS and Vas-score for worst pain: Spearman’s correlation= 0.37
  • CNFDS and Vas-score for mean pain: Spearman’s correlation = 0.19
  • CNFDS and SF36 physical: Spearman’s correlation = -0.44
  • CNFDS and SF36 mental: Spearman’s correlation = -0.44 [8]

Responsiveness

The responsiveness of the CNFDS is similar to the responsiveness of the Neck Disability Index, the Northwick Park Pain Questionnaire and the Neck Pain and Disability Scale. All these scales showed good sensitivity to change with nearly identical SRM values. (SRMCNFDS=0,89; p<0,01). (Grades of Recommendation: B) [4] [3]


The short-term and long-term responsiveness correlate very well to self-reported changes in pain. [3] Studies showed that there is a small correlation demonstrated with pain scores at 6 weeks (r=0.49; p<0,0001), 4 months (r=0.48; p<0,0001), and a moderate correlation at 12 months (r=0.54; p<0,0001). (Grades of Recommendation: B) [7][9][3]


For the French version of the CNFDS the sensitivity to change is 0.33 in patients with marked worsening, in patients with worsening it is 0.02. In patients with no change and with an improvement and with a marked improvement the sensitivity to change is respectively 0.10, 0.51 and 0.68. (Grades of Recommendation: B) [8]


The designer of the questionnaire believes that the CNFDS’s possible decreased sensitivity regarding individual questions is compensated for by the greater number of questions included. (Grades of Recommendation: D) [3] No quantification estimated minimal clinically important difference was reported. [7]

Miscellaneous

  • There are no ceiling or floor effects detected in the CNFDS. [6] [5]
  • The total scoring is free of age and gender bias. [3]


Links


Recent Related Research (from PubMed)


References

  1. 1.0 1.1 1.2 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. (level of evidence:2C)
  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. 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 3.13 3.14 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. (level of evidence 2C)
  4. 4.0 4.1 4.2 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. (level of evidence 2C)
  5. 5.0 5.1 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. (level of evidence 2A)
  6. 6.0 6.1 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. . (level of evidence 2C)
  7. 7.0 7.1 7.2 7.3 7.4 7.5 7.6 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. (level of evidence 2A)
  8. 8.0 8.1 8.2 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. (level of evidence: 2C
  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. (level of evidence 2A)