Psychometric properties of the EQ-5D-5L for aboriginal Australians: a multi-method study

INTRODUCTION: In Australia, health-related quality of life (HRQoL) instruments have been adopted in national population surveys to inform policy decisions that affect the health of Aboriginal and Torres Strait Islanders. However, Western-developed HRQoL instruments should not be assumed to capture Indigenous conceptualization of health and well-being. In our study, following recommendations for cultural adaptation, an Indigenous Reference Group indicated the EQ-5D-5L as a potentially valid instrument to measure aspects of HRQoL and endorsed further psychometric evaluation. Thus, this study aimed to investigate the construct validity and reliability of the EQ-5D-5L in an Aboriginal Australian population. METHODS: The EQ-5D-5L was applied in a sample of 1012 Aboriginal adults. Dimensionality was evaluated using Exploratory Graph Analysis. The Partial Credit Model was employed to evaluate item performance and adequacy of response categories. Area under the receiver operating characteristic curve (AUROC) was used to investigate discriminant validity regarding chronic pain, general health and experiences of discrimination. RESULTS: The EQ-5D-5L comprised two dimensions, Physiological and Psychological, and reliability was adequate. Performance at an item level was excellent and the EQ-5D-5L individual items displayed good discriminant validity. CONCLUSIONS: The EQ-5D-5L is a suitable instrument to measure five specific aspects (Mobility, Self-Care, Usual activities, Pain/Discomfort, Anxiety/Depression) of Aboriginal and Torres Strait Islander HRQoL. A future research agenda comprises the investigation of other domains of Aboriginal and Torres Strait Islander HRQoL and potential expansions to the instrument.