Work

Chronic fatigue syndrome in long COVID: prevalence and impact on health-related quality of life and health status. A cross-sectional study. BioICOPER study

Year: 2026

Type: article

Abstract: Background Long COVID (LC) and Chronic Fatigue Syndrome (CFS) share clinical features and are associated with reduced quality of life and functional impairment. However, the additional burden of LC–CFS overlap remains limited. We aimed to assess the prevalence of LC–CFS overlap and its association with health-related quality of life (HRQoL) and health status outcomes, including sex differences. Methods Cross-sectional study including 304 participants with LC. CFS was diagnosed using Fukuda criteria. Health status and HRQoL were assessed with Short Form-36 Survey (SF-36), Goldberg’s Anxiety and Depression Scale (GADS), Post-COVID19 Functional Scale (PCFS), Spanish Chronic Pain Grade Scale (SCPGS), modified Medical Research Council Dyspnea Scale (mMRC) and Malnutrition Universal Screening Tool (MUST). Group comparisons and adjusted regression models were performed. In addition, a sex-by-LC-CFS overlap interaction term was included in all regression models. Results 171 subjects (56.3%) met LC-CFS overlap, more frequently in women (63.8% vs 40.2%). CFS overlap group was related with worse outcomes compared with those with LC alone in most of health questionnaires, including SF-36, GADS, SCPGS, PCFS and mMRC. Compared with LC alone, LC-CFS overlap was associated with poorer scores in SF-36 physical and mental health components (PCS: B=-9.73, MCS: B=-5.36), anxiety (B = 2.02), depression (B = 2.83,95), SCPGS (B = 12.56), PCFS A component (OR = 13.98) and B component (OR 11.27), and mMRC (OR = 7.17). No association was found with MUST or sex interaction. Conclusions Over half of participants met criteria for LC–CFS overlap, more frequently in women. This subgroup showed worse HRQoL and health status. Identifying overlap in Primary Care may improve risk stratification and support targeted management strategies. Trial registration: This study was carried out with data from subjects of BioICOPER project. The study protocol has been published, and it has been registered in ClinicalTrials.gov in April 2023 with the registration number NCT05819840.

Source: BMC Family Practice

DOI: 10.1186/s12875-026-03625-7