The NDI is a modification of the Oswestry Low Back Pain Disability Index . It is a patient-completed, condition-specific functional status questionnaire with 10 items including pain, personal care, lifting, reading, headaches, concentration, work, driving, sleeping and recreation. The NDI has sufficient support and usefulness to retain its current status as the most commonly used self-report measure for neck pain .
The NDI is translated in many languages (greek, german, dutch, Korean, Spanish, french) each has its own validity and reliability outcomes. Because there is an impact of translation on validity.
The NDI can be used to evaluate the patients status presence and to evaluate the evolution during the therapy
Intended Population 
- Chronic neck pain
- musculoskeletal neck pain
- whiplash injuries and whiplash associated disorders
- cervical radiculopathy
Method of Use
The NDI can be scored as a raw score or doubled and expressed as a percent . Each section is scored on a 0 to 5 rating scale, in which zero means ‘No pain’ and 5 means ‘Worst imaginable pain’. Al the points can be summed to a total score. The test can be interpretated as a raw score, with a maximum score of 50, or as a percentage.
0 points or 0% means : no activity limitations ,
50 points or 100% means complete activity limitation.
A higher score indicates more patient-rated disability. There is no statement in the original literature on how to handle missing data. To use the NDI for patient decisions, a clinically important change was calculated as 5 points, with a sensitivity of 0.78 and a specificity of 0.80.
Mean duration of the test: 3 to 7.8 minutes 
Some benchmarks can be found in literature but methodologically they were not described and theire validity and reliability are questionable Vernon and Moir presented the following interpretation:
• 0-4 points (0-8%) no disability,
• 5-14 points ( 10 – 28%) mild disability,
• 15-24 points (30-48% ) moderate disability,
• 25-34 points (50- 64%) severe disability,
• 35-50 points (70-100%) complete disability
- Macdermid JC, Walton DM, Avery S, Blanchard A, Etruw E, McAlpine C, Goldsmith CH. Measurement properties of the neck disability index a sustematic review Journal of Orthopedic and Sports Physical Therapy. 2009 May;39(5):400-17.
- Vernon H, Mior S. The neck disability index: A study of reliability and validity. Journal of Manipulative and Physiological Therapeutics, 1991, 14:409-15 Riddle DL,
- Stratford PW. Use of generic versus region specific functional status measures on patients with cervical spine disorders. Physical Therapy, 1998;78:951-963
- Stratford PW, Riddle DL, Binkley JM et al (1999) Using the neck disability index to make decisions concerning individual patients Physiotherapy Canada, 2,107-112