Assessing health state utilities for people with myalgic encephalomyelitis/chronic fatigue syndrome in Australia using the EQ-5D-5L, AQoL-8D and EQ-5D-5L-psychosocial instruments

Abstract:

Purpose: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic condition with a constellation of symptoms presenting as severe and profound fatigue of ≥ 6 months not relieved by rest. ME/CFS affects health-related quality of life (HRQoL), which can be measured using multi-attribute health state utility (HSU) instruments. The aims of this study were to quantify HSUs for people living with ME/CFS, and to identify an instrument that is preferentially sensitive for ME/CFS.

Methods: Cross-sectional national survey of people with ME/CFS using the AQoL-8D and EQ-5D-5L. Additional questions from the AQoL-8D were used as ‘bolt-ons’ to the EQ-5D-5L (i.e., EQ-5D-5L-Psychosocial). Disability and fatigue severity were assessed using the De Paul Symptom Questionnaire-Short Form (DSQ-SF). HSUs were generated using Australian tariffs. Mean HSUs were stratified for sociodemographic and clinical factors. Bland-Altman plots were used to compare the three HSU instruments.

Results: For the 198 participants, mean HSUs (95% confidence intervals) were EQ-5D-5L: 0.46 (0.42-0.50); AQoL-8D: 0.43 (0.41-0.45); EQ-5D-5L-Psychosocial: 0.44 (0.42-0.46). HSUs were substantially lower than population norms: EQ-5D-5L: 0.89; AQoL-8D: 0.77. As disability and fatigue severity increased, HSUs decreased in all three instruments. Bland-Altman plots revealed interchangeability between the AQoL-8D and EQ-5D-5LPsychosocial. Floor and ceiling effects of 13.5% and 2.5% respectively were observed for the EQ-5D-5L instrument only.

Conclusions: ME/CFS has a profound impact on HRQoL. The AQoL-8D and EQ-5D-5L-Psychosocial can be used interchangeably: the latter represents a reduced participant burden.

Source: Orji NC, Cox IA, Jason LA, Chen G, Zhao T, Rogerson MJ, Kelly RM, Wills K, Hensher M, Palmer AJ, de Graaff B, Campbell JA. Assessing health state utilities for people with myalgic encephalomyelitis/chronic fatigue syndrome in Australia using the EQ-5D-5L, AQoL-8D and EQ-5D-5L-psychosocial instruments. Qual Life Res. 2023 Aug 10. doi: 10.1007/s11136-023-03498-8. Epub ahead of print. PMID: 37561337. https://link.springer.com/article/10.1007/s11136-023-03498-8 (Full text)

Operationalizing Substantial Reduction in Functioning Among Young Adults with Chronic Fatigue Syndrome

Abstract:

PURPOSE: Chronic fatigue syndrome and myalgic encephalomyelitis are fatiguing illnesses that often result in long-term impairment in daily functioning. In reviewing case definitions, Thrope et al. (Fatigue 4(3):175-188, 2016) noted that the vast majority of case definitions used to describe these illnesses list a “substantial reduction” in activities as a required feature for diagnosis. However, there is no consensus on how to best operationalize the criterion of substantial reduction.

METHOD: The present study used a series of receiver operating curve (ROC) analyses to explore the use of the Medical Outcomes Study Short-Form-36 Health Survey (SF-36), designed by Ware and Shelbourne for operationalizing the substantial reduction criterion in a young adult population (18-29 years old). We compared the sensitivity and specificity of various cutoff scores for the SF-36 subscales and assessed their usefulness in discriminating between a group of young adults with a known diagnosis of chronic fatigue syndrome or myalgic encephalomyelitis (n = 98) versus those without that diagnosis (n = 272).

RESULTS: The four top performing subscales and their associated cutoffs were determined: Physical Functioning ≤ 80, General Health ≤ 47, Role Physical ≤ 25, and Social Functioning ≤ 50. Used in combination, these four cutoff scores were shown to reliably discriminate between the patients and controls in our sample of young adults.

CONCLUSION: The implications of these findings for employing the substantial reduction criterion in both clinical and research settings are discussed.

Source: Gleason KD, Stoothoff J, McClellan D, McManimen S, Thorpe T, Katz BZ, Jason LA.  Operationalizing Substantial Reduction in Functioning Among Young Adults with Chronic Fatigue Syndrome. Int J Behav Med. 2018 Jun 5. doi: 10.1007/s12529-018-9732-1. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/29872989

Neurocognitive functioning in chronic fatigue syndrome

Abstract:

Although substantial research has been conducted on chronic fatigue syndrome (CFS) over the past decade, the syndrome remains poorly understood. The most recent case definition describes CFS as being characterized both by disabling fatigue and by subjective reports of difficulty with concentration and “short-term” memory. However, research into the neurocognitive and psychological functioning of individuals with CFS has provided mixed objective results. The current paper reviews studies that have examined the neurocognitive and/or psychological functioning of individuals with CFS. Changes in research design and instruments employed to study individuals with CFS are suggested.

 

Source: DiPino RK, Kane RL. Neurocognitive functioning in chronic fatigue syndrome. Neuropsychol Rev. 1996 Mar;6(1):47-60. http://www.ncbi.nlm.nih.gov/pubmed/9144668

 

The Multidimensional Fatigue Inventory (MFI) psychometric qualities of an instrument to assess fatigue

Abstract:

The Multidimensional Fatigue Inventory (MFI) is a 20-item self-report instrument designed to measure fatigue. It covers the following dimensions: General Fatigue, Physical Fatigue, Mental Fatigue, Reduced Motivation and Reduced Activity. This new instrument was tested for its psychometric properties in cancer patients receiving radiotherapy, patients with the chronic fatigue syndrome, psychology students, medical students, army recruits and junior physicians. We determined the dimensional structure using confirmatory factor analyses (LISREL’s unweighted least squares method). The hypothesized five-factor model appeared to fit the data in all samples tested (AGFIs > 0.93). The instrument was found to have good internal consistency, with an average Cronbach’s alpha coefficient of 0.84. Construct validity was established after comparisons between and within groups, assuming differences in fatigue based on differences in circumstances and/or activity level. Convergent validity was investigated by correlating the MFI-scales with a Visual Analogue Scale measuring fatigue (0.22 < r < 0.78). Results, by and large, support the validity of the MFI.

 

Source: Smets EM, Garssen B, Bonke B, De Haes JC. The Multidimensional Fatigue Inventory (MFI) psychometric qualities of an instrument to assess fatigue. J Psychosom Res. 1995 Apr;39(3):315-25. http://www.ncbi.nlm.nih.gov/pubmed/7636775