Clinical evolution and risk factors in patients infected during the first wave of COVID-19: A two-year longitudinal study

A limited number of longitudinal studies have examined the symptoms associated with long-COVID-19. We conducted an assessment of symptom onset, severity and patient recovery, and determined the percentage of patients who experienced reinfection up to 2 years after the initial onset of the disease. Our cohort comprises 377 patients (>=18 years) with laboratory-confirmed COVID-19 in a secondary hospital (Madrid, Spain), throughout March 3-16, 2020. Disease outcomes and clinical data were followed-up until August 12, 2022. We reviewed the evolution of the 253 patients who had survived as of April 2020 (67.1%). Nine died between April 2020 and August 2022. A multivariate regression analysis performed to detect the risk factors associated with long-COVID-19 revealed that the increased likelihood was associated with chronic obstructive lung disease (OR 14.35, 95% CI 1.89-109.09; 'p' = 0.010), dyspnea (5.02, 1.02-24.75; 'p' = 0.048), higher LDH (3.23, 1.34-7.52; 'p' = 0.006), and lower D-dimer levels (0.164, 0.04-0.678; 'p' = 0.012). Reinfected patients ('n' = 45) (47.8 years; 39.7-67.2) were younger than non-reinfected patients (64.1 years; 48.6-74.4)) ('p' < 0.001). Patients who received a combination of vaccines exhibited fewer symptoms (44.4%) compared to those who received a single type of vaccine (77.8%) ('p' = 0.048). Long-COVID-19 was detected in 27.05% (66/244) of patients. The early detection of risk factors helps predict the clinical course of patients with COVID-19. Middle-aged adults could be susceptible to reinfection, highlighting the importance of prevention and control measures regardless of vaccination status.