The Neck Disability Index (NDI) is a common self-report questionnaire designed to assess how neck pain influences a patient’s daily life. This tool provides a structured way to quantify the severity of neck-related disability. Healthcare professionals utilize the NDI to gain a clearer understanding of a patient’s functional limitations.
Understanding the NDI Questionnaire
The NDI questionnaire comprises ten distinct items, each addressing a specific aspect of daily living potentially affected by neck pain. These items include:
Pain intensity
Personal care
Lifting
Reading
Headaches
Concentration
Work
Driving
Sleeping
Recreation
For each of these ten items, a patient selects one of six possible responses. These responses typically range from 0 to 5, with higher numbers indicating greater difficulty or pain associated with that activity. The patient is instructed to choose only the single response that best describes their situation for each item.
Calculating the NDI Score
Calculating the NDI score involves a straightforward process to quantify a patient’s self-reported disability. For each of the ten items on the questionnaire, the selected response is assigned a numerical value from 0 to 5. A score of 0 indicates no disability or pain for that item, while a score of 5 represents the highest level of disability or pain. Once each item has been assigned its corresponding score, these individual scores are summed together to obtain a total raw score. The maximum possible raw score is 50, which would signify complete disability across all assessed areas.
Should a patient omit an answer for one or more items, the calculation needs adjustment to maintain accuracy. A common method involves calculating the average score of the completed items and then using this average to estimate the total score as if all items were completed. The raw score, which ranges from 0 to 50, is commonly converted into a percentage for easier interpretation by multiplying the raw score by two.
Interpreting NDI Scores
Once the NDI score is calculated, it can be interpreted to categorize the level of neck-related disability a patient experiences. The categories are:
A raw score of 0 to 4 (or 0-8% as a percentage) generally indicates no disability.
Mild disability is typically represented by a raw score ranging from 5 to 14 (10-28% as a percentage).
Patients with moderate disability usually score between 15 and 24 (30-48% as a percentage).
A score of 25 to 34 (50-68% as a percentage) suggests severe disability.
A raw score greater than 34 (70-100% as a percentage) indicates complete disability.
These ranges provide a general framework for understanding the impact of neck pain on a patient’s life, though clinical judgment always plays a role in the overall assessment.
Significance in Patient Care
The NDI serves as a valuable instrument for healthcare professionals within clinical settings. It provides a standardized, objective measure of a patient’s subjective experience of pain and disability. This allows clinicians to effectively track changes in a patient’s condition over time. By comparing NDI scores at different points, healthcare providers can assess the effectiveness of various treatments and interventions. The NDI also facilitates clearer communication between patients and their clinicians regarding the impact of neck pain.