Neck Pain and Disability Scale (NPAD)

The Neck Pain and Disability Scale (NPAD), alongside the Neck Disability Index (NDI), is one of the most widely used self-report questionnaires for assessing disability in patients with neck pain. NPAD was developed to fill the gap left by earlier, more general pain and disability measures such as the Oswestry Disability Questionnaire and the Pain Disability Index, which were not neck-specific.

Originally developed in the United States by Wheeler and colleagues, NPAD has since been translated and validated in multiple languages, including French, German, Turkish, Portuguese, Italian, Dutch, and Korean. Across these versions, it has demonstrated high validity and reliability.

Purpose and Application

NPAD is designed for patients with:

• Neck syndromes

• Chronic neck pain

• Patients after cervical fusion (C1–C2) or surgery

It is suitable for both clinical practice and research, providing a patient-centered assessment of pain intensity and disability related to neck conditions.

Structure of the NPAD

The NPAD contains 20 items, covering:

• Neck pain intensity

• Movement restrictions

• Emotional and cognitive impact of neck pain

• Effects on daily living activities

• Social, occupational, and recreational function

Each item is scored using a 10 cm Visual Analogue Scale (VAS), with responses ranging from 0 (no problem) to 5 (severe problem).

• Total score range: 0–100 (higher = more severe disability).

• Completion time: under 5 minutes.

Method of Administration

1. The patient marks their response on the VAS line for each item.

2. The scores are summed to create a total NPAD score.

3. Valid scoring requires ≥85% of items completed (no more than 15% missing).

Evidence

Reliability

• German version (NPAD-d): Cronbach’s alpha = 0.94, indicating excellent internal consistency (Scherer et al.)

• Dutch version (NPAD-DLV): Cronbach’s alpha = 0.93 (Jorritsma et al.)

• Dutch version (NPAD-DLV): ICC = 0.76 (0.57–0.87), limits of agreement ±20.9 across repeated measurements (Jorritsma et al.)

• Bremerich et al.: Cronbach’s alpha = 0.97 (total scale), 0.95–0.97 (subscales), test-retest reliability = 0.97

Validity

NPAD has shown strong validity across multiple translations (Turkish, French, German, Portuguese, Italian, Korean, Iranian, Dutch).

• Content validity: Covers ICF domains (body functions, activities, participation).

• Construct validity:

  • Item-to-total correlations = 0.41–0.83

  • High correlation with NDI (r = 0.77 for NPAD-DLV)

  • Correlates with VAS-pain (0.54) and VAS-function (0.57)

Responsiveness

NPAD has been shown to be responsive to clinical change, making it suitable for monitoring treatment outcomes in:

• Chronic neck pain

• Post-surgical patients (e.g., C1–C2 fusion)

Key Findings

• Validated and reliable for acute and chronic neck pain

• Applicable across various populations, including cervical radiculopathy and whiplash

• Measures emotional and cognitive domains, unlike the NDI

• Useful for treatment monitoring due to responsiveness

• Best used as part of a comprehensive clinical assessment

Limitations

• Not specifically designed to assess psychological factors separately

• Less emphasis on detailed work and social factors

• May have slightly lower discriminatory power between mild and moderate disability compared to NDI in some populations

Clinical Conclusion

The Neck Pain and Disability Scale (NPAD) is a thoroughly validated, reliable, and widely translated tool for evaluating disability related to neck pain. It captures not only pain intensity but also the impact of neck pain on daily life, emotions, and cognition, making it a valuable complement to other clinical assessments.

Sources:

1. Eva Blozik, Wolfgang Himmel, Michael M. Kochen, Christoph Herrmann-Lingen, Martin Scherer. Sensitivity to change of the Neck Pain and Disability Scale. Spine. 2011;20:882-889. (level of evidence B)

2. Martin Scherer, Eva Blozik, Wolfgang Himmel et al. Psychometric properties of a German version of the neck pain and disability scale. Spine. 2008;17:922-929. (level of evidence B)

3. Wim Jorritsma, Grietje E. de Vries, Pieter U. Dijkstra et al. Neck Pain and Disability Scale and Neck Disability Index: validity of Dutch language versions. Spine. 2010. (level of evidence B)

4. Wim Jorritsma, Grietje E. de Vries, Pieter U. Dijkstra et al. Neck Pain and Disability Scale and Neck Disability Index: reproducibility of Dutch language versions. Spine. 2010. (level of evidence B)

5. Bremerich FH, Grob D, Dvorak J, Mannion AF. The Neck Pain and Disability Scale: cross-cultural adaptation into German and evaluation of its psychometric properties in chronic neck pain and C1-2 fusion patients. Spine. 2008;33(9):1018-27. (level of evidence B)

6. RobRoy L. Martin. A Survey of Self-reported Outcome Instruments for the Foot and Ankle. Journal of orthopaedic sports physical therapy. 2007.