Translation, cultural adaptation and psychometric validation of the SF-6D measure of health-related quality of life for use in Arabic-Speaking countries.

ABSTRACT

BACKGROUND: The SF-6D is a generic, six-dimensional health-related quality of life (HRQoL) measure derived from a selection of items from the SF-36. OBJECTIVES: To translate, culturally adapt and validate the SF-6D for use in Arabic-speaking countries. METHODS: The International Quality of Life Assessment (IQOLA) methodology was followed. Two forward translations, one consensus and one backward translation were undertaken. Difficulties encountered were categorized as grammatical, idiomatic, semantic/conceptual, and cultural. The content validity of the final version was tested and Cronbach's alpha test of internal consistency was used for assessing reliability. Confirmatory factor analysis (CFA), was also used to assess construct validity and to test a pre-specified relationship of observed measures. RESULTS: Minor changes were made to the forward translation to improve cultural appropriateness. The Backward translation did not reveal major problems and equivalence to the original was confirmed following committee review. A total of 470 participants from Jordan, Egypt, UAE, Qatar and Palestine completed the translated SF-6D. All the incremental indices values are ≥0.90 and close to 1. Item loading values ranged from 0.52 to 0.87. The measurement model weight for those with chronic health conditions ranged from 0.68 to 0.91, and from 0.42 to 0.73 for those without. The percentage of variation in self-reported health state was about 55%. The measurement weight of SF-6D on self-reported health state among chronic responders was 0.87 while among responders reporting no chronic disease was 0.61. The t-value for the difference in measurement weight was -8.93 (p ≤ 0.01). CONCLUSION: Arabic translation and cultural adaptation of SF-6D has resulted in an acceptable and culturally-adapted version that can be used in Arabic-speaking countries. Reliability and validity have been confirmed as well as ability to assess the difference in quality of life between patients with chronic health conditions and healthy individuals.