Health questionnaires and assessment tools are used increasingly in the Welsh health service to help monitor patients’ health status and health-related quality of life. In the bilingual context of Wales, health questionnaires are required in Welsh as well as English. However, their availability is lacking and LLAIS, based at NWORTH, Bangor University is tasked with increasing the availability and accessibility of Welsh language versions of health measures.

Simply translating does not capture the essence of health measures. It is vital that constructs have the same meaning. Different language versions need to have parity, and group comparisons should reflect true group differences rather than linguistic discrepancies or cultural bias in translation.

This study focuses exclusively on a step by step systematic approach to the linguistic validation of the Welsh language version of the PROMIS-10 global health questionnaire (see http://www.micym.org/llais/static/translations.html for more details on the translation guidelines including forward and back translation, consensus review and cognitive testing).

For the linguistic validation of the Welsh version of the PROMIS-10, 12 service user representatives, lay participants, and healthcare professionals contributed to ensure that the concepts and language was easily understood by native Welsh speakers.

A Welsh language version of the PROMIS-10 is now available for use by clinicians and researchers from the micym.org website which hosts all available Welsh language patient reported outcome measures http://nworth-ctu.bangor.ac.uk/documents/PROMIS-10.pdf. The psychometric properties of these measures when administered to a wider patient group will be the focus of a future study.