Two years and counting: A prospective cohort study on the scope and severity of post-COVID symptoms across diverse patient groups in the Netherlands-insights from the CORFU study

Klein, D.O.; Waardenburg, S.F.; Janssen, E.B.N.J.; Wintjens, M.S.J.N.; Imkamp, M.; Heemskerk, S.C.M.; ... ; CAPACITY COVID Collaborative Consortium (2025)

Article / Letter to editor

Importance: Little research has been done on post-COVID symptoms at 24 months postinfection and on the association these may have on health-related quality of life (HRQOL).

Objective: We assessed the prevalence and severity of post-COVID symptoms and quantified EuroQol 5 Dimension 5 Level (EQ-5D-5L), self-perceived health question (EuroQol Visual Analogue Scale (EQ-VAS)) and health utility scores (HUS) up to 24 months follow-up.

Design: The longitudinal multiple cohort CORona Follow-Up (CORFU) study combines seven COVID-19 patient cohorts and a survey among the general public. The participants received questionnaires on several time points. Participants were stratified by: without a known SARS-CoV-2 infection (control group), proven SARS-CoV-2 infection but non-hospitalised, proven SARS-CoV-2 infection hospitalised to the ward, and proven SARS-CoV-2 infection hospitalised to the intensive care unit (ICU).

Setting: In this study, data of seven COVID-19 patient cohorts and a survey among the general public are included.

Participants: Former COVID-19 patients and controls participated in this cohort study.

Main outcomes and measures: Former COVID-19 patients and non-COVID-19 controls were sent questionnaires on symptoms associated with post-COVID condition. The CORFU questionnaire included 14 symptom questions on post-COVID condition using a five-level Likert-scale format. Furthermore, HRQOL was quantified using the EuroQol EQ-5D-5L questionnaire: EQ-VAS and the EQ-5D-5L utility score. The EQ-5D-5L questionnaire includes five domains that are scored on a five-point Likert scale: mobility, self-care, usual activities, pain/discomfort and anxiety/depression.

Results: A total of 901 participants (and 434 controls) responded at 24 months follow-up. In all former COVID-19 patients, the presence of post-COVID condition at 24 months was observed in 62 (42.5%, 95% CI 34.3% to 50.9%) of the non-hospitalised patients, 333 (65.0%, 95% CI 60.7% to 69.2%) of the hospitalised ward patients and 156 (63.2%, 95% CI 56.8% to 69.2%) of the ICU patients, respectively (p<0.001). The most common symptoms included fatigue, sleep problems, muscle weakness/pain and breathing issues, with hospitalised participants reporting most often having symptoms. Multiple post-COVID symptoms were significantly associated with EQ-5D-5L measures. The mean and SD of the EQ-VAS were 71.6 (17.9), 70.0 (17.3) and 71.4 (17.5) for non-hospitalised, ward and ICU participants, respectively, and 75.6 (17.7) for the controls (p<0.001). The HUS resulted in 0.81 (0.20), 0.77 (0.19) and 0.79 (0.22) for non-hospitalised, hospitalised ward and ICU participants, respectively, and 0.84 (0.19) for the control group (CG) (p<0.001).

Conclusions: Many former COVID-19 patients experience post-COVID symptoms at 24 months follow-up, with the highest prevalence in hospitalised participants. Also, former patients reported a lower HRQOL.

• Post-Acute COVID-19 Syndrome
• Prevalence
• Patients
• COVID-19

• All authors: Klein, D.O.; Waardenburg, S.F.; Janssen, E.B.N.J.; Wintjens, M.S.J.N.; Imkamp, M.; Heemskerk, S.C.M.; Birnie, E.; Bonsel, G.J.; Warle, M.C.; Jacobs, L.M.C.; Hemmen, B.; Verbunt, J.; Bussel, B.C.T. van; Santen, S. van; Kietelaer, B.L.J.H.; Jansen, G.; Klok, F.A.; Kruif, M.D. de; Vernooy, K.; Haagsma, J.A.; Asselbergs, F.W.; Linschoten, M.; Cals, J.W.L.; Cate, H. ten; Horst, I.C.C. van der; Wilmes, N.; Ghossein-Doha, C.; Kuijk, S.M.J. van; CAPACITY COVID Collaborative Consortium
• Date: 2025-09-12
• Journal: BMJ Open
• Volume: 15
• Issue: 9
• DOI: doi:10.1136/bmjopen-2024-093639