Symptom profiles and their risk factors in patients with post COVID-19 condition: A longitudinal Dutch observational cohort study

Background: To improve research and care for patients with post COVID-19 condition, more insight into different subtypes of post COVID-19 condition and their risk factors is urgently needed. We aimed to validate risk factors of post COVID-19 condition in general and for specific symptom profiles.
Methods: This study is based on data collected within the Lifelines COVID-19 cohort. Mean pre- and post SARS-CoV-2 infection symptom scores were compared to classify post COVID-19 condition. Latent Profile Analysis was used to identify symptom profiles. Logistic and multinomial regression analyses were used to examine the association between demographic, lifestyle and health-related risk factors and post COVID-19 condition and symptom profiles, respectively. 
Results: Of 3,465 participants having had COVID-19, 18.5% (n=642) classified for post COVID-19 condition. Four symptom profiles were identified: muscle pain, fatigue, cardiorespiratory, and ageusia/anosmia. Female sex was a risk factor for the muscle pain and fatigue profiles. Being overweight or obese increased risk for all profiles, except the fatigue profile. Having a chronic disease increased the risk of all profiles except the ageusia/anosmia profile, with the cardiorespiratory profile being only significant in case of multimorbidity. Being unvaccinated increased risk of the ageusia/anosmia profile.
Conclusion: Findings from this study suggest that SARS-CoV-2 may trigger different pathophysiological mechanisms that may result in different subtypes of post COVID-19 condition. These subtypes have shared and unique risk factors. Further characterization of symptom profiles and quantification of the individual and societal impact of specific symptom profiles are pressing challenges for future research.
Keywords: COVID-19, long COVID, post COVID-19 condition, symptom clusters, risk factors