Cross-Cultural Adaptation and Validation of the Norwegian Short-form McGill Pain Questionnaire-2 in Low Back-Related Leg Pain.

STUDY DESIGN: A prospective observational study with translation and psychometric analyses of a questionnaire.

OBJECTIVE: Cross-cultural adaptation of the Short-Form McGill Pain Questionnaire-2 into Norwegian.

SUMMARY OF BACKGROUND DATA: The different versions of the McGill Pain Questionnaire (MPQ) have been important and influential tools for pain assessment. To more reliably assess qualities of both neuropathic and non-neuropathic pain, the Short-Form MPQ was revised in 2009 (SF-MPQ-2), including seven additional descriptors. No Norwegian adaptation of the SF-MPQ-2 have been performed.

METHODS: A translation of the SF-MPQ-2 was performed based on established guidelines. Forward-translations were compared and discussed in an expert workgroup. A synthesis was achieved by consensus. A backward translation was reviewed and consolidated with the forward translations to confirm linguistic equivalence. A pre-final version was tested in 8 patients, who were interviewed to evaluate acceptability and comprehension of the questionnaire. Minor changes were implemented. The questionnaire was externally proofread. The final Norwegian version (NSF-MPQ-2) was tested for content and construct validity and internal consistency reliability in a population with low back-related leg pain.

RESULTS: The backward translation was in good accordance with the original version. The pre-final version showed excellent acceptability and comprehension in initial patient-testing. The NSF-MPQ-2 showed satisfactory content and construct validity, including responsiveness to change, and acceptable internal consistency reliability as measured by Cronbach's alpha. A confirmatory factor analysis showed poor fit for the established four-factor structure, especially regarding the neuropathic subscale.

CONCLUSIONS: The NSF-MPQ-2 showed excellent acceptability and comprehension, satisfactory content and construct validity, including responsiveness to change, and internal consistency reliability as measured by Cronbach's alpha. However, a confirmatory factor analysis raised concerns regarding the factor-structure in the present population. Until more evidence emerges for the four-factor solution we suggest the NSF-MPQ-2 should be used as a single measure.

LEVEL OF EVIDENCE: 3.