Measurement properties of translated versions of neck-specific questionnaires: a systematic review

BACKGROUND: Several disease-specific questionnaires to measure pain and disability in patients with neck pain have been translated. However, a simple translation of the original version doesn't guarantee similar measurement properties. The objective of this study is to critically appraise the quality of the translation process, cross-cultural validation and the measurement properties of translated versions of neck-specific questionnaires. METHODS: Bibliographic databases were searched for articles concerning the translation or evaluation of the measurement properties of a translated version of a neck-specific questionnaire. The methodological quality of the selected studies and the results of the measurement properties were critically appraised and rated using the COSMIN checklist and criteria for measurement properties. RESULTS: The search strategy resulted in a total of 3641 unique hits, of which 27 articles, evaluating 6 different questionnaires in 15 different languages, were included in this study. Generally the methodological quality of the translation process is poor and none of the included studies performed a cross-cultural adaptation. A substantial amount of information regarding the measurement properties of translated versions of the different neck-specific questionnaires is lacking. Moreover, the evidence for the quality of measurement properties of the translated versions is mostly limited or assessed in studies of poor methodological quality. CONCLUSIONS: Until results from high quality studies are available, we advise to use the Catalan, Dutch, English, Iranian, Korean, Spanish and Turkish version of the NDI, the Chinese version of the NPQ, and the Finnish, German and Italian version of the NPDS. The Greek NDI needs cross-cultural validation and there is no methodologically sound information for the Swedish NDI. For all other languages we advise to translate the original version of the NDI.