CLINICAL QUESTION
What are the benefits and harms of different doses of inhaled corticosteroids (ICS) for patients with asthma?
BOTTOM LINE
For patients with a high risk of severe asthma exacerbations, using high-dose ICS instead of moderate dosing provides a clinically meaningful reduction in severe exacerbations (number needed to treat = 19). Higher doses are known to increase the risk of adverse events like cataracts, pneumonia, and fractures, which must be balanced against this benefit. (Level of Evidence = 1a)
SYNOPSIS
Maintenance therapy for patients with asthma commonly consists of the combination of ICS and a long-acting beta agonist, with the dose of the ICS titrated to control symptoms. The researchers identified randomized trials that compared different doses of ICS in patients 12 years and older with asthma, based on the Global Initiative for Asthma classifications of low-, moderate-, and high-dose ICS. The authors identified 12 studies with 6,373 participants: seven studies compared moderate-dose with high-dose ICS, four compared moderate-dose with low-dose, and one compared low-dose with high-dose. The duration of the studies was 12 to 52 weeks, and the studies were generally judged to be at low risk of bias.
Most comparisons showed no differences between groups. The primary patient-oriented outcome difference was that patients who received a high-dose ICS were less likely to have one or more severe exacerbation (defined as worsening of symptoms requiring a systemic steroid) than those who received a moderate dose (Peto odds ratio = 0.81; 95% CI, 0.67-0.98). The number needed to treat to prevent a severe exacerbation was 19 if the patient's baseline risk was 50%, 28 if it was 20%, and 91 if it was 5%. Higher doses yielded greater improvements in forced expiratory volume in 1 second and asthma symptoms, but these differences were small and not clinically significant. There were no significant differences in serious adverse events, although given the relatively small numbers of patients and short durations of the studies, these comparisons were likely underpowered.
Study Design: Meta-analysis (randomized controlled trials)
Funding Source: Government
Setting: Various (meta-analysis)
