2. Definitions of asthma exacerbation used in primary trials.

Study	Definition
Castro 2014	Meeting criteria for treatment failure and 1 or more of the following: failure to respond to rescue algorithm within 48 hours; FEV1 of less than 50% of baseline measurement on 2 consecutive measurements; FEV1 of less than 40% of predicted level on 2 consecutive measurements; use of 16 puffs/day or more of as‐needed levalbuterol for 48 hours; experiencing an exacerbation of asthma according to physician opinion; use of oral or parenteral corticosteroids due to asthma.
Jensen 2016	Exacerbation requiring rescue oral corticosteroids, documented in medical or pharmacy records or both
Lewis 2012	Exacerbation not defined or reported in study manuscript
Majak 2009	Exacerbation not defined or reported in study manuscript; authors confirmed that no exacerbations requiring systemic corticosteroid treatment occurred in the study
Majak 2011	Reported but not defined in study manuscript; authors confirmed that no exacerbations requiring systemic corticosteroid treatment occurred in the study
Martineau 2015	Deterioration in asthma resulting in (A) treatment with oral corticosteroids, or (B) hospital admission or emergency department treatment, or (C) decrease in the morning PEFR to more than 25% below the mean run‐in value on 2 or more consecutive days
Tachimoto 2016	Worsening of asthma symptoms prompting a need for a change in asthma treatment (from authors)
Urashima 2010	Asthma attack that included wheezing, improved by inhalation of a beta‐stimulant in participants who already had a diagnosis of asthma; authors confirmed that no exacerbations requiring systemic corticosteroid treatment occurred in the study
Yadav 2014	Reported but not defined in study manuscript

FEV1, forced expiratory volume in one second; PEFR, peak expiratory flow rate.