Analysis of persistent COVID-19 subtypes and their impact on quality of life

Background: Persistent COVID-19 (PC) affects individuals who have survived the acute phase of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and present prolonged and fluctuating symptoms. These symptoms are multisystemic and significantly impair quality of life. The high degree of clinical variability hinders classification and management in clinical practice. This study aimed to classify patients according to their predominant symptoms and explore their impact on their quality of life, taking into account sociodemographic variables, personal history, and lifestyle. Methods: This was a cross-sectional observational study. The subjects came from the dedicated persistent COVID-19 clinic of internal medicine at Salamanca Hospital and from primary care clinics in Salamanca. Clinical, sociodemographic, and symptom data were collected via standardised questionnaires. Quality of life was assessed via the SF-36 questionnaire. Symptom grouping was performed via nonparametric statistical techniques. Results : The study included 305 individuals (68.2% women) with a mean age of 52.7 ± 11.91 years. Eighty-two percent were infected before completing primary vaccination. Fatigue was the most common symptom (71.4%), along with other symptoms, such as a lack of energy, memory loss, dyspnea, and sleep disturbance. Women presented more symptoms than men did. Five clusters were identified: the largest, Cluster 1 (51.8%), with respiratory/cardiovascular, systemic, and musculoskeletal symptoms. With respect to quality of life, Cluster 5 presented the highest scores, and Cluster 1 presented the lowest scores, especially for the physical components. Significant differences were observed between clusters on the SF-36 questionnaire scales and domains, highlighting a poorer quality of life in the most symptomatic clusters. Conclusions : This study identified five subgroups of patients with PC, and those with more symptoms presented poorer quality of life. Dyspnea and fatigue are indicators of this deterioration, with women being more affected. Cluster 1 reported the worst quality of life, whereas Cluster 5 had the best quality of life, highlighting the need for individualised therapeutic approaches. Trial registration: Registered on Clinicaltrials.gov with identifier NCT05819840.