Risk factors for adverse outcomes in elderly patients with asthma and severe COVID-19 at the hospital and early post-hospital stages

Background. Mortality and COVID-19 related factors are thoroughly analyzed. Given the large number of hospitalized patients, the potential short- and long-term COVID-19 related complications, further research is needed on the possible consequences of hospitalization, especially in higher-risk patients, after prolonged hospitalization and intensive care admission.

Aim. To study the clinical course and outcomes of severe COVID-19 in elderly patients with asthma at the hospital and early post-hospital stages.

Materials and methods. The study included 131 elderly patients (WHO, 2020) >60 years old, n=131 with asthma, hospitalized for severe COVID-19. Of these, 86 (65.6%) patients survived, 30 (22.9%) died in the hospital, and 15 (14.9%) patients died after discharge from the hospital (in the 90-day post-hospital period). COVID-19 was confirmed by laboratory tests (SARS-CoV-2 PCR RNA test) and/or clinically and radiologically. All patients had a documented history of asthma. Patients were followed up during the hospital stay and for 90 days after discharge.

Results. Comparison of outcomes showed that in the groups of patients with a fatal outcome (regardless of the stage), the Charlson comorbidity index, respiratory rate, extent of lung damage assessed by computed tomography, the absolute leukocyte and neutrophil number and the ratio of neutrophils to lymphocytes were statistically significantly higher. The absolute number of eosinophils was lower in these groups. In the group of patients who died during hospitalization, severe (IV–V) asthma (p=0.03), steroid use during the previous year (p=0.02), chronic heart failure with a reduced ejection fraction (p=0.009) were more common, and atopic asthma phenotype was less common (p=0.02). In those who died after discharge, more common were non-invasive ventilation and diabetes mellitus (p<0.001). The multivariate regression analysis model revealed the most significant predictors of mortality at the hospital and early post-hospital stages.

Conclusion. Adverse outcomes of severe COVID-19 in elderly patients with asthma include hospital and post-hospital mortality. The most significant predictors of mortality are the comorbidity index and low eosinophil count. Hospital mortality is associated with a higher ratio of neutrophils to lymphocytes and lower total protein levels; early (90-day) post-hospital mortality is associated with extensive lung damage shown by computed tomography and diabetes mellitus.