Long COVID is not a uniform syndrome: Evidence from person-level symptom clusters using latent class analysis

Sophie C M van den Houdt; Isabel A L Slurink; Gaëtan Mertens

doi:10.1016/j.jiph.2023.12.019

Long COVID is not a uniform syndrome: Evidence from person-level symptom clusters using latent class analysis

J Infect Public Health. 2024 Feb;17(2):321-328. doi: 10.1016/j.jiph.2023.12.019. Epub 2023 Dec 29.

Authors

Sophie C M van den Houdt¹, Isabel A L Slurink¹, Gaëtan Mertens²

Affiliations

¹ Center of Research on Psychological disorders and Somatic diseases (CoRPS), Department of Medical & Clinical Psychology, Tilburg University, PO box 90153, 5000LE Tilburg, the Netherlands.
² Center of Research on Psychological disorders and Somatic diseases (CoRPS), Department of Medical & Clinical Psychology, Tilburg University, PO box 90153, 5000LE Tilburg, the Netherlands. Electronic address: g.mertens@tilburguniversity.edu.

PMID: 38183882
DOI: 10.1016/j.jiph.2023.12.019

Abstract

Background: The current study aims to enhance insight into the heterogeneity of long COVID by identifying symptom clusters and associated socio-demographic and health determinants.

Methods: A total of 458 participants (M_age 36.0 ± 11.9; 46.5% male) with persistent symptoms after COVID-19 completed an online self-report questionnaire including a 114-item symptom list. First, a k-means clustering analysis was performed to investigate overall clustering patterns and identify symptoms that provided meaningful distinctions between clusters. Next, a step-three latent class analysis (LCA) was performed based on these distinctive symptoms to analyze person-centered clusters. Finally, multinominal logistic models were used to identify determinants associated with the symptom clusters.

Results: From a 5-cluster solution obtained from k-means clustering, 30 distinctive symptoms were selected. Using LCA, six symptom classes were identified: moderate (20.7%) and high (20.7%) inflammatory symptoms, moderate malaise-neurocognitive symptoms (18.3%), high malaise-neurocognitive-psychosocial symptoms (17.0%), low-overall symptoms (13.3%) and high overall symptoms (9.8%). Sex, age, employment, COVID-19 suspicion, COVID-19 severity, number of acute COVID-19 symptoms, long COVID symptom duration, long COVID diagnosis, and impact of long COVID were associated with the different symptom clusters.

Conclusions: The current study's findings characterize the heterogeneity in long COVID symptoms and underscore the importance of identifying determinants of different symptom clusters.

Keywords: COVID-19; Clustering; Latent class analysis; Long COVID; Post-COVID-19.

MeSH terms

Adult
COVID-19*
Cluster Analysis
Female
Humans
Latent Class Analysis
Male
Middle Aged
Post-Acute COVID-19 Syndrome*
Surveys and Questionnaires
Young Adult