The long-term effect of COVID-19 infection on lung volumes and respiratory indices among hospitalized patients up to one year after discharging from hospital: a population- based cohort study

Abstract

Abstract Background and purpose As the number of COVID-19 survivors increased, countless people have been affected by the pulmonary consequences of this infection. They are likely to suffer permanent lung damage and long-term pulmonary dysfunction (15). The present study aimed at investigating the long-term term effect of COVID-19 infection on lung volumes and respiratory indices among hospitalized patients up to one year after discharge from the hospital conducting a population-based cohort study. Materials and Methods This population-based cohort study was conducted by inviting patients with COVID-19 admitted to Afzalipour Hospital in Kerman (a reference hospital during the pandemic in Kerman province, Iran) during September, October, and November 2022, to the present survey. Respondents who agreed to help with the survey were followed for one year, and they were examined in terms of respiratory outcomes on two occasions at eight months and one year after discharge from the hospital. A spirometry test was also performed for the satisfied patients. Demographic information and hospitalization time information were extracted from their hospital records. Data were analyzed using SPSS and R software. Results Out of 1954 hospitalized patients, 500 patients accepted the study invitation. In terms of disease severity, 61 patients (12.2%) were classified as suffering from severe disease and 439 patients (87.8%) were classified as moderate. Cough and shortness of breath during activity were common symptoms that were observed in the first follow-up, although these symptoms were more common in patients with severe disease than in patients with moderate disease (P = 0.012 and P = 0.023, respectively). Despite decreasing patients' breathing problems during the first follow-up, a significant percentage of patients were, still, suffering from these problems 12 months after discharge from the hospital. Among the patients who performed spirometry, 54.9% had low lung volume, 10.8% were classified as obstructive lung patients, and 44.1% were reported as restrictive lung patients. Conclusion COVID-19 causes long-term complications in the lungs that continue for at least one year after the infection. Our results showed that Obstructive complications are more frequent than limiting complications.