Persistent/Late-Onset Complications of COVID-19 in General Population: A Cross-Sectional Study in Tehran, Iran.

Background: After recovery from acute phase of the COVID-19, some patients suffer from persistent/late-onset complications. The main objective of this study was to investigate the prevalence of such complications in a large scale of COVID-19 patients in Tehran, Iran. Methods: In this cross-sectional study, those patients who called Tehran emergency medical services center and were visited by the emergency medical technicians from 20 March 2020 until 21 September 2020 and diagnosed as a confirmed COVID-19 case were enrolled. The minimum required sample size was estimated 385 cases, and they were selected randomly. The patients were interviewed by phone at least 4 weeks since initiation of their symptoms. Using a pre-prepared checklist, made by an expert panel who were involved in management of COVID-19 patients, data were collected on the types and duration of the complications, clinical information, and factors which could interfere with developing the complications. All analyses were performed using STATA 16 software. The association of the prevalence of each complication with independent factor was assessed using Chi-square test (or Fisher's exact test) for categorical variable, and the mean difference of numerical variables in the two groups (with and without complication) was assessed using independent t-test. Statistical significance was accepted at P value<0.05. Results: Four-hundred forty-seven patients participated in the study. Among our total population, 345 (77.2%) patients experienced at least one of the persistent/late-onset complications. Cardiopulmonary and then skin-related symptom categories were reported in 179 (40.0%) and 173 (38.7%) patients, respectively, and were the most prevalent persistent/late-onset complications. The associations of long term persistent/late-onset complications with older ages (P=0.04), female (P<0.001), psychological stress (P=0.01), and inadequate rest after illness (P<0.001) were significant. Conclusion: The findings of this study indicate that a significant number of patients will experience persistent/late-onset complications, both physically and mentally, after recovering from acute phase of COVID-19. Thus, physicians should have adequate resources and support to care for the patients to help them cope with the condition.