Abstract
PURPOSE: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Post COVID-19 Condition (PCC) are debilitating, chronic multi-systemic illnesses that require multidisciplinary care. However, people with ME/CFS (pwME/CFS) and people with PCC (pwPCC) are often precluded from accessing necessary disability and social support services. These unmet care needs exacerbate the existing illness burdens experienced by pwME/CFS and pwPCC. To deliver appropriate care and optimise health outcomes for pwME/CFS and pwPCC, the development of evidence-based healthcare policies that recognise the disabling impacts of these illnesses must be prioritised. This systematic review summarises the health-related quality of life (HRQoL) of pwME/CFS and pwPCC when compared with healthy controls (HCs) to elucidate the impacts of these illnesses and guide healthcare policy reform. METHODS: CINAHL, Embase, MEDLINE, PubMed, PsycINFO and the Web of Science Core Collection were systematically searched from 1st January 2003 to 23rd July 2024. Eligible publications included observational studies capturing quantitative HRQoL data among pwME/CFS or pwPCC when compared with HCs. The use of validated patient-reported outcome measures (PROMs) was mandatory. Eligible studies were also required to employ the most stringent diagnostic criteria currently available, including the Canadian Consensus Criteria or International Consensus Criteria for ME/CFS and the World Health Organization case definition for PCC (PROSPERO ID: CRD42024501309). RESULTS: This review captured 16 studies, including eight studies among pwME/CFS, seven studies among pwPCC and one study among both illness cohorts. Most participants were female and middle-aged. All pwPCC had experienced prolonged COVID-19 symptoms for at least three months. When compared with HCs, all HRQoL domains were significantly impaired among pwME/CFS and pwPCC. Both illnesses had a salient impact on physical health, including pain and ability to perform daily and work activities. While direct comparisons between pwME/CFS and pwPCC were limited by inconsistencies in the PROMs employed, comparable impact trends across HRQoL domain scores were observed. CONCLUSION: ME/CFS and PCC have similar, profound impacts on HRQoL that warrant access to multidisciplinary disability and social support services. Future research must harmonise HRQoL data collection and prioritise longitudinal investigations among pwME/CFS and pwPCC to characterise PCC subgroups (including those fulfilling ME/CFS criteria) and predictors of prognosis.