ab1901

Spanish version of the Northwick Park Neck Pain Questionnaire: Reliability and validity

T. González¹, A. Balsa², J. Sáinz de Murieta³, E. Zamorano³, I. González³, E. Martin-Mola²

¹Instituto Provincial de Rehabilitación, Hospital Universitario Gregorio Marañón; ²Hospital Universitario La Paz; ³Escuela Universitaria de Fisioterapia de la ONCE, Madrid, Spain.

ABSTRACT
Objective
To validate a Spanish version of the Northwick Park Neck Pain Questionnaire (NPQ) and to prove its usefulness in clinical practice.

Methods
We studied 58 patients with non-inflammatory neck pain of more than 4 months duration. A blind back translation of the NPQ was made, and the resulting back-translation version was then compared with the original. The NPQ comprises 9 questions with 5 statements of increasing difficulty. Patients completed the questionnaire 3 times: on their initial assessment; 8-10 days later (test-retest); and after physiotherapy treatment 3 months later. Neck pain was assessed by a visual analogue scale (VAS).

Results
Fifty-three patients completed the questionnaire (90%). There was a good intra-class correlation between the test-retest NPQ (r = 0.63), indicating good agreement. For each of the 9 sections, agreement ranged from r = 0.43 to r = 0.85, p < 0.05 in all cases. Correlation with the VAS was also good, between r = 0.51 (test) and r = 0.74 (retest) (p < 0.05 in all cases). Pain measured by the VAS increased according to the NPQ score, grouped by percentages (p = 0.003). The mean scores for each section increased with that of the intensity of pain, in most sections showing good internal consistency. Pain and the NPQ score improved after treatment (56.1 ± 20.2 to 29.9 ± 20.1, p = 0.0001 and 45.9% ± 12.7% to 28.9% ± 15.3%, p = 0.0001 respectively), as did all the other items except for driving (p < 0.05).

Conclusions
The Spanish version of the NPQ is a feasible, reliable and valid instrument to measure pain in Spanish- speaking patients with chronic neck pain.

Key words
Neck pain, Northwick Park Neck Pain Questionnaire, validity, transcultural equivalency.

Supported by an educational grant from Escuela Universitaria de Fisioterapia de la ONCE, Madrid.
Please address correspondence and reprint requests to: Dra. González, Rheumatology Unit, Instituto Provincial de Rehabilitación, Hospital Universitario Gregorio Marañón, Francisco Silvela 40, 28028 Madrid, Spain.