Investigating Associations between EQ-5D-5L Health State Utilities and Disability and Fatigue Severity in People with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in Australia

OBJECTIVES: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a chronic debilitating condition with disabling impact on health-related quality of life (HRQoL). There are no Health State Utility (HSU) values and hence HRQoL for people with ME/CFS in Australia using the EQ-5D-5L multi attribute utility instrument. This study aims to quantify HSUs and assess associations with disability and fatigue severity for people living with ME/CFS in Australia.

METHODS: A cross-sectional national survey using convenience sampling was conducted. EQ-5D-5L was used to quantify HSUs. Short Form DePaul Symptom Questionnaire (DSQ-SF) captured disability and fatigue severity levels. Univariable and multivariable regression models examined the associations between EQ-5D-5L HSUs, disability and fatigue severity levels.

RESULTS: Among 198 study participants with self-reported ME/CFS in our study, 80% were females while 16.2% were males. Males had higher HSU values (0.53 (95% CI: 0.44 - 0.62)) compared to females (0.45 (95% CI: 0.40 - 0.50)). Study mean HSU of 0.46 (95% CI: 0.42-0.50), was substantially lower than similar age and gender matched population norms (0.89). An inverse relationship was observed between HSUs and disability and fatigue severity. As HSUs decreased, disability severity increased: from 0.69 (95% CI: 0.63 – 0.75) for mild disability to 0.44 (95% CI: 0.39 – 0.49) for moderate disability and 0.02 (95% CI: -0.02 - 0.17) for severe disability. Disability and fatigue severity were found to be statistically significant predictors of HSU values.

CONCLUSIONS: This study generated HSUs for people with ME/CFS in Australia using EQ-5D-5L Australian tariffs. The results showed an inverse relationship between HSU values and disability and fatigue severity. These findings would serve as a reference for constructing health economic models to evaluate interventions for people with ME/CFS.