Neck Disability Index (NDI)

Pain and function evaluation in patients with neck disability

The Neck Disability Index (NDI) is a validated 10-item-questionnaire for the assessment of neck pain. The items of the questionnaire assess deficits in physical and social functioning as well as pain and everyday activities. It is based on the Oswestry Disability Index, one of the most common PROMs in assessment of low back pain.

The NDI has already been used in a number of studies that deal with cervical spine diseases such as cervical spondylotic myelopathy, symptomatic disc herniation, symptomatic disc degeneration, and symptoms like radiculopathy. The items were constructed to represent different dimensions including pain intension, physical functioning, headache, concentration, and ability to work.

Indication

The questionnaire has been developed for the evaluation of neck pain and physical functioning.

In the past, the NDI has been used for patient groups with chronic, non-specific neck pain 1 2, cervical myelopathy, and radiculopathy due to spondylotic changes or herniating/degenerative disc diseases 3. Moreover, the tool has found use in the evaluation of patient outcomes after cervical disc arthroplasty surgery. 4 5 6

Items - Dimensions - Completion time

The questionnaire has to be answered by selecting 1 of 6 response options per item.

One main dimension of the NDI is pain, including general pain and pain linked with physical parameters like personal care, lifting, reading, driving and recreation. Parameters like headache, concentration, sleeping and the ability to work are also evaluated.

There is different information about how much time it takes to complete the NDI. Stratford 7 reported a completion time of 3 minutes. Meanwhile, Wlodyka-Demaille et al. 8 found out that it took a mean of 7.4 minutes to finish the questionnaire.

Scoring method

The responses concerning each item are given a score of 0 to 5. All 10 items are scored in this manner. After all items have been completed, the final score is calculated as follows:

(Sum of all scored points / highest possible total score) × 100%

Example: (16 points scored / 50) x 100% = 32%

If an item is skipped or not applicable, the highest possible total score will be 45 instead of 50. The final score is always a percentage to allow for skipped or nonapplicable items. The minimal clinically important change is 21%. 9

Score interpretation

The lower the score, the better the patient’s state of neck related health.

0% – 10%: no disability

21% – 30%: mild disability

31% – 50%: moderate disability

50% – 70%: severe disability

71% – 100%: complete disability 10

The NDI is validated in several languages. 11 12 13 14 Version 2.0 is the most current English version.
MAPI Research Trust (Lyon, France) 15
For students, physicians, non-funded academic users and for routine clinical practice, there is a direct access to the questionnaire and available translations without costs. For funded academic users, healthcare organizations, commercial users, and IT companies, fees may apply and a licensing agreement must be entered. 16
The NDI is valid in several clinical indications. Moreover, the tool has a wide international use and acceptance. In comparison to other outcome measures, the Neck Disability Index is quick to answer, and its scoring method is easy and intuitive.
Ceiling- and floor effects (errors that occur when the measuring range is exceeded/undercutted) have been observed in high (>80%) and low (<20%) score area 17 which decreases the ability of detecting change in these score ranges. The NDI doesn’t including any aspects regarding psychological and psychosocial health.

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References

  1. Ylinen, Jari, et al. “Active neck muscle training in the treatment of chronic neck pain in women: a randomized controlled trial.” Jama 289.19 (2003): 2509-2516.
  2. Bronfort, Gert, et al. “A randomized clinical trial of exercise and spinal manipulation for patients with chronic neck pain.” Spine 26.7 (2001): 788-797.
  3. Fehlings, Michael G., et al. “Anterior versus posterior surgical approaches to treat cervical spondylotic myelopathy: outcomes of the prospective multicenter AOSpine North America CSM study in 264 patients.” Spine 38.26 (2013): 2247-2252.
  4. Vaccaro, Alexander, et al. “Clinical outcomes with selectively constrained SECURE-C cervical disc arthroplasty: two-year results from a prospective, randomized, controlled, multicenter investigational device exemption study.” Spine 38.26 (2013): 2227-2239.
  5. Mummaneni, Praveen V., et al. “Clinical and radiographic analysis of cervical disc arthroplasty compared with allograft fusion: a randomized controlled clinical trial.” Journal of Neurosurgery: Spine 6.3 (2007): 198-209.
  6. Heller, John G., et al. “Comparison of BRYAN cervical disc arthroplasty with anterior cervical decompression and fusion: clinical and radiographic results of a randomized, controlled, clinical trial.” Spine 34.2 (2009): 101-107.
  7. Stratford, Paul W. “Using the Neck Disability Index to make decisions concerning individual patients.” Physiother Can (1999): 107-119.
  8. Wlodyka-Demaille, Samantha, et al. “French translation and validation of 3 functional disability scales for neck pain.” Archives of physical medicine and rehabilitation 83.3 (2002): 376-382.
  9. Pool, Jan JM, et al. “Minimal clinically important change of the Neck Disability Index and the Numerical Rating Scale for patients with neck pain.” Spine 32.26 (2007): 3047-3051.
  10. MacDermid, Joy C., et al. “Measurement properties of the neck disability index: a systematic review.” Journal of orthopaedic & sports physical therapy 39.5 (2009): 400-417.
  11. Cramer, Holger, et al. “Validation of the German version of the Neck Disability Index (NDI).” BMC musculoskeletal disorders 15.1 (2014): 1-7.
  12. Vernon, Howard, and Silvano Mior. “The Neck Disability Index: a study of reliability and validity.” Journal of manipulative and physiological therapeutics (1991).
  13. Aslan, Emine, et al. “The cultural adaptation, reliability and validity of neck disability index in patients with neck pain: a Turkish version study.” Spine 33.11 (2008): E362-E365.
  14. Swanenburg, Jaap, et al. “Validity and reliability of a German version of the Neck Disability Index (NDI-G).” Manual therapy 19.1 (2014): 52-58.
  15. https://eprovide.mapi-trust.org/instruments/neck-disability-index
  16. https://eprovide.mapi-trust.org/instruments/neck-disability-index#contact_and_conditions_of_use
  17. Jorritsma, Wim, et al. “Neck pain and disability scale and neck disability index: validity of Dutch language versions.” European Spine Journal 21.1 (2012): 93-100.

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