Cross-cultural adaptation and validation of the NASS outcomes instrument in Spanish patients with low back pain

Eur Spine J. 2005 Aug;14(6):586-94. doi: 10.1007/s00586-004-0871-5. Epub 2005 Feb 17.


Objectives: The aim of the study was to evaluate validity, reliability, responsiveness and practicality of the NASS-AAOS (North American Spine Society--American Academy of Orthopaedic Surgeons) questionnaire in patients with low back pain.

Methods: The sample included 70 patients with herniated disk, stenosis, chronic low back pain of unknown etiology or acute low back pain. They were assessed twice before treatment (test--retest) and a third measure six months to one year afterwards.

Results: The mean time of administration was 24 and 20 min for the test and post-treatment evaluation, respectively. Cronbach's alpha coefficient was between 0.78 and 0.92 on the baseline test and 0.90 or higher on the post-treatment evaluation. The test--retest reproducibility was 0.95 (0.91--0.98) for 'neurological symptoms', 0.82 (0.63--0.91) for 'pain/disability' and 0.63 (0.25--0.82) for 'expectations'. The associations with other measures and clinical criteria were generally moderate to high and in the expected direction. The effect size for 'pain/disability' in combination with 'neurological symptoms' was 2.02 for patients who improved versus an effect of -0.09 in patients who were stable between test and retest; the area under the curve on this joint scale was 0.81 (0.69--0.90).

Conclusions: The instrument is valid, sensitive to clinical changes and reliable for comparisons between groups, but further study is needed for its application in monitoring individual patients.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Cross-Cultural Comparison
  • Humans
  • Intervertebral Disc Displacement / diagnosis
  • Language
  • Low Back Pain / diagnosis*
  • Pain Measurement / methods
  • Pain Measurement / standards*
  • Reproducibility of Results
  • Spain
  • Surveys and Questionnaires / standards*