Clinical features

Note:

• Patients who have 3 or more emergency department visits within 6 months ^a or have a hospital admission within 12 months ^b are at increased risk of having a relapse.
• Leaving hospital within 24 hours without achieving 50% predicted PEFR increases the risk of relapse. ^a

Frequent ED visits and early discharge without improvement increase the risk of asthma relapse.

Patient	Prognostic Factor	Outcome	CER	OR (95% CI)	NNF+ (95% CI)
severe asthma exacerbation a	3 or more ED visits within last 6 months independent	relapse at 8 weeks	45% (39% to 51%)	2.3 (1.6 to 3.4)	5 (4 to 9)
severe asthma exacerbation a	left before 24 hours without achieving 50% predicted PEFR independent	relapse at 8 weeks	45% (39% to 51%)	2.6 (1.6 to 4.1)	4 (3 to 9)

Previous hospital admissions in the last year are associated with asthma relapse

Outcome	Risk Factor	PEER	OR (95% CI)	NNH (95% CI)
asthma relapse b	admission in last year independent	30%	3.0 (1.0 to 9.3)	4 (2 to infinity)