The Neck Disability Index (NDI)
The Neck Disability Index (NDI) is a modified version of the Oswestry Low Back Disability Index (ODI) used by clinicians and researchers to quantify disability related to — you guessed it — neck pain.
It was developed in the late 1980s, and first published in 1991. The NDI was the first instrument for measuring patient-reported disability in neck pain patients. Since 1991, a number of other questionnaires for neck pain patients have been developed, but the NDI remains the oldest and most widely-used of these instruments.
This 10 question survey is filled out by the patients, and asks condition-specific questions related to functional status such as pain, personal care, lifting, reading, headaches, concentration, work, driving, sleeping, and recreation. Each question is scored on a scale of 0-5, with zero indicating the least amount of disability. To obtain the index, the scores of all questions are summed and then multiplied by two.
The NDI has been rigorously tested over the years, and has proven to be a reliable, valid, and responsive PRO measure. It has sufficient support and usefulness to retain its current status as the most commonly used self- reported measure for neck pain.
License and Cost
For students, physicians, clinical practices and not-funded academic users, the NDI is free to use and download. For any funded academic user, healthcare organization, commercial users and IT companies, you are required to submit a request to obtain the needed information and license agreement.
To learn more about the NDI, please visit their website: eprovide.mapi-trust.org/instruments/neck-disability-index.