The relationship between the phenotype of long COVID symptoms and one-year psychosocial outcomes: an exploratory clustering analysis.

The impact of Coronavirus Disease 2019 (COVID-19) is not limited to acute symptoms; it also extends to post-infection sequelae, such as long COVID and post-COVID conditions. These conditions are characterized by various symptoms, such as malaise, fatigue, and cognitive dysfunction, and are considered to reflect different underlying pathologies. Using a cluster analysis, we hypothesized that long COVID may have different psychosocial outcomes depending on the phenotype. This study is based on the COVID-19 RECOVERY STUDY II (CORES II) conducted in 20 centers in Japan. CORES II included patients aged 20 years and older who were hospitalized and discharged alive between April and September 2021. In CORES II, information collected at hospitalization was followed by an investigation one year after diagnosis into post-infection symptoms, physical and mental health, and patients' social circumstances. Long COVID symptoms, based on symptoms one month after infection, and psychosocial well-being, including anxiety, depression, post-traumatic stress disorder, and quality of life (QOL), one year after onset were assessed via questionnaires provided one year after diagnosis. We performed a cluster analysis based on long COVID symptoms. We also compared the psychosocial status between clusters. We identified five clusters of symptoms in 746 patients. These clusters were characterized by severe multi-organ dysfunction, olfactory and gustatory disturbances, shortness of breath, muscle weakness, and hair loss. The severe multi-organ dysfunction cluster included a large number of patients with malaise and who were more likely to have a poor psychosocial status one year after onset. In addition, the olfactory and gustatory disturbance cluster appeared to have the second highest depression and anxiety scores after the multi-organ dysfunction cluster. The results obtained on the five-symptom clusters suggest that the multi-organ dysfunction phenotype with malaise and olfactory and gustatory disturbances has psychosocial consequences. Patients with these phenotypes require more extensive follow-ups and interventions.