High-dose inhaled corticosteroids versus add-on long-acting β-agonists in asthma: an observational study

Background: Guidelines recommend that for patients uncontrolled on inhaled corticosteroids (ICSs), step-up options include an increase in ICS dosage or addition of a long-acting beta-agonist (LABA). Controversy persists about the best option in routine practice.

Objective: To compare asthma outcomes in patients whose first step-up from ICS monotherapy was by addition of LABA (LABA cohort) or increase in ICS dosage or formulation (ICS cohort).

Methods: Observational study using the General Practice Research Database, comparing outcomes in the following 12 months with regression modeling allowing for baseline cohort differences: age, sex, socioeconomic status, body mass index, comorbidity (rhinitis, heart disease), smoking status, short-acting beta-agonist (SABA) use, oral corticosteroid use, and use of asthma complicating medication.

Results: We found 46,930 patients in the ICS and 17,418 in the LABA cohort. In adjusted analysis, the odds ratio (95% CI) of successful treatment (no hospitalization, no oral corticosteroid use, average daily SABA use <1 dose/d) was lower in the ICS cohort (0.75; 0.72-0.79). The adjusted odds ratio of needing rescue SABA prescriptions was higher in the ICS cohort (1.67; 1.59-1.76). However, the adjusted odds of using any oral corticosteroids were lower (0.75; 0.71-0.78), particularly of using 3 or more courses (0.50, 0.46-0.55), and the adjusted odds of respiratory hospitalization were lower (0.69; 0.59-0.81).

Conclusion: Although symptomatic control and rescue bronchodilator use may be improved by the addition of a LABA to ICS, there may be a lower risk of severe exacerbations and hospitalizations from ICS dose increase. (J Allergy Clin Immunol 2009;123:116-21.)