17. Relapse/Return to the emergency department.

Intervention/Comparison	Outcome	Illustrative comparative risks (95% CI)		Relative effect: risk ratio (95% CI)	Number of participants (studies)	Certaintyof the evidence (GRADE)	Comments: overview authors' assessment of the certainty of evidence
		Assumed risk	Corresponding risk
		With comparator	With intervention
Anticholinergic and SABA vs SABA alone (Griffiths 2013)	Relapse	45 per 1000	48 per 1000 (31 to 76)	1.07 (0.68 to 1.68)	1389 (10)	Low	Certainty downgraded due to serious imprecision and risk of bias in review (single author selected possible citations)
Oral LTRA vs control (Watts 2012)	Relapse within 7 days	83 per 1000	32 per 1000 (1 to 727)	0.39 (0.02 to 8.73)	22 (1)	Low	Certainty downgraded due to very serious imprecision
Inhaled anticholinergics + SABA vs SABA alone for children hospitalised with asthma (Vezina 2014)	Relapse within 72 hours of discharge from hospital	0 per 1000	0 (not estimable)	Not estimable	80 (1)	Low	Certainty downgraded due to risk of bias in review (single author selected possible citations) and serious imprecision
IV magnesium sulfate (Griffiths 2016)	Return to ED within 48 hours	22 per 1000	9 per 1000 (1 to 211)	0.41 (0.02 to 9.71)	85 (2)	Low	Certainty downgraded due to very serious imprecision

CI: confidence interval; ED: emergency department; GRADE: Grading of Recommendations Assessment, Development and Evaluation; LTRA: leukotriene receptor antagonist; SABA: short acting beta2‐agonist.