Background: Chronic illnesses were reported to be poor prognostic factors associated with severe illness and mortality in Coronavirus disease 2019 (COVID-19) infection. The association with asthma, however, is limited and controversial, especially for mild asthma.
Methods: A territory wide retrospective study was conducted to investigate the association between asthma and the prognosis of COVID-19. All patients with laboratory confirmed in Hong Kong for COVID-19 from the 23 January to 30 September 2020 were included in the study. Severe diseases were defined as those who develop respiratory complications, systemic complications, and death.
Results: Among the 4498 patients included in the analysis, 165 had asthma, with 141 having mild asthma. Patients with asthma were significantly more likely to require invasive mechanical ventilation (incidence = 17.0% odds ratio [OR] = 4.765, p < 0.001), oxygen therapy (incidence = 39.4%, OR = 3.291, p < 0.001), intensive care unit admission (incidence = 21.2%, OR = 3.625, p < 0.001), and systemic steroid treatment (incidence = 34.5%, OR = 4.178, p < 0.001) and develop shock (incidence = 16.4%, OR = 4.061, p < 0.001), acute kidney injury (incidence = 6.1%, OR = 3.281, p = 0.033), and secondary bacterial infection (incidence = 56.4%, OR = 2.256, p < 0.001). They also had significantly longer length of stay. Similar findings were also found in patients with asthma of the Global Initiative for Asthma (GINA) steps 1 and 2 upon subgroup analysis.
Conclusions: Asthma, regardless of severity, is an independent prognostic factor for COVID-19 and is associated with more severe disease with respiratory and systemic complications.
Keywords: COVID-19; asthma; invasive mechanical ventilation; prognosis.
© 2022 The Authors. The Clinical Respiratory Journal published by John Wiley & Sons Ltd.