Asthma may up risk of hospitalization in kids with COVID-19

Children with asthma who are infected with SARS-CoV-2 virus are at an increased risk of hospitalization, especially those whose asthma is poorly controlled, compared with children without asthma, according to data from the EAVE II* study.

“Although most COVID-19 cases in children are mild … identifying which group of school-aged children might benefit from earlier doses of the COVID-19 vaccines has important implications for vaccine delivery worldwide,” said the researchers.

“This is particularly important considering the potential limited vaccine supplies and the lower absolute risk of serious COVID-19 in children,” they highlighted.

The national incident cohort study involved 752,867 children aged 5–17 years linked to the EAVE II dataset. Children with signs of uncontrolled asthma were identified based on records of prior hospitalization due to asthma or use of oral corticosteroids in the past 2 years. [Lancet Respir Med 2021;doi:10.1016/S2213-2600(21)00491-4]

Among the total cohort population, 63,463 (8.4 percent) had clinician-diagnosed asthma — out of which 4,339 (6.8 percent) were tested positive for COVID-19 by RT-PCR testing. Sixty-seven (1.5 percent) of the COVID-19 cases were admitted to hospital.

Compared to children without asthma, those with asthma were more likely to have confirmed SARS-CoV-2 infections (6.8 percent vs 5.8 percent).

Moreover, the rates of hospitalization due to COVID-19 were also higher among children with asthma than those without (1.5 percent vs 0.9 percent).

In particular, children whose asthma was poorly controlled were more likely to be hospitalized with COVID-19 compared with children without asthma or those with well-controlled asthma.

When analysed based on prior asthma hospitalization as an indicator uncontrolled asthma, the risk of being hospitalized with COVID-19 was more than sixfold higher in children with poorly controlled asthma (adjusted hazard ratio [HR], 6.40, 95 percent confidence interval [CI], 3.27–12.53) and 1.3 times higher in those with well controlled asthma (HR, 1.36, 95 percent CI, 1.02–1.80), compared with children without asthma.

When taking oral corticosteroid prescriptions as an indicator of uncontrolled asthma, the corresponding HRs for COVID-19 hospitalization was 3.38 (95 percent CI, 1.84–6.21) for children who had ≥3 prescribed courses of corticosteroids, 3.53 (95 percent CI, 1.87–6.67) for those with ≥2 corticosteroid preceripstions, 1.52 (95 percent CI, 0.90–2.57) for those with one prescription, and 1.34 (95 percent CI, 0.98–1.82) for children who did not need any corticosteroids, compared with those without asthma.

The risk remained significant even after controlling for multiple variables such as age, sex, comorbidity, socioeconomic status, and prior hospitalization.

“Although the HR was elevated, the overall risk of admission to hospital with SARS-CoV-2 in children with asthma was low,” the researchers reported, noting that only one in 380 children whose asthma was poorly controlled was hospitalized with COVID-19.

“The findings from this linkage of multiple data sources have helped inform the prioritisation of school-aged children with poorly controlled asthma for vaccines,” they pointed out.

As children with poorly controlled asthma were more likely to be hospitalized, they were more likely to undergo testing for COVID-19 than those with well controlled asthma or without asthma, which might explained the higher incidence of SARS-CoV-2-positive cases among children whose asthma was poorly controlled, according to the researchers.

“Over the coming winter, many well recognized respiratory viruses are anticipated in children, and in combination with seasonal changes, these are expected to increase the frequency and severity of asthma exacerbations,” wrote Drs Rachel Harwood and Ian Sinha from the University of Liverpool, Liverpool, UK, in a linked a commentary. [Lancet Respir Med 2021;doi:10.1016/S2213-2600(21)00509-9]

“A focus on excellent asthma control, including the delivery of the influenza vaccine, and improving air quality and hygiene in schools is essential for all children with asthma to reduce their susceptibility to exacerbations over the coming winter,” they advised.

*EAVE II: Early Pandemic Evaluation and Enhanced Surveillance of COVID-19