TABLE 1.

Inclusion and exclusion criteria

	Inclusion	Exclusion
Population	Patients (adults or children) with confirmed COVID-19 based on RT-PCR or clinically highly suspect cases	Studies which only referenced “COVID-19” broadly
Exposure	Severe asthma diagnosed by clinicians or by validated or nonvalidated guidelines	Self-reported asthma patients
Comparator	Patients (adults or children) with confirmed COVID-19 based on RT-PCR and without pre-existing severe asthma diagnosis	Studies without any comparator
Outcome	1) Risk of hospitalisation for people with severe asthma 2) Risk of ICU admission/mechanical ventilation for people with severe asthma 3) Risk of death for people with severe asthma	1) Asymptomatic or mild to moderate COVID-19 symptoms 2) Studies focusing only on the pathophysiology of COVID-19 in asthma or severe asthma
Study design	Studies of any design besides those specified in the exclusion criteria	Modelling studies, opinion pieces, editorials, reviews and laboratory studies
Geographical location	Studies conducted in any country or countries	No restrictions based on geographical location

COVID-19: coronavirus disease 2019; RT-PCR: reverse transcriptase PCR; ICU: intensive care unit.