Single maintenance and reliever therapy predicts fewer asthma exacerbations

Single maintenance and reliever therapy (SMART) predicts fewer asthma exacerbations and could help better manage persistent asthma, according to findings from a recent systematic review and meta-analysis published in the JAMA.

SMART, or single inhaler therapy, is defined as the combination of inhaled corticosteroids and long-acting ß-agonists (LABAs) as both controller and quick relief therapy, or medications used on an as-needed basis.

“The objective of this review was to systematically identify and analyze data from trials that compared use of SMART among patients with persistent asthma vs inhaled corticosteroids with or without a LABA used as controller therapy and SABAs [short-acting ß-agonists] as reliever therapy among patients aged 5 years or older,” wrote primary author Diana M. Sobieraj, PharmD, Department of Pharmacy Practice, University of Connecticut School of Pharmacy, Storrs, CT.

Experts in international guidelines recommend the use of SMART as controller and quick-relief therapy; however, there are currently no combinations of inhaled corticosteroids and LABA approved for this use in the United States.

The researchers evaluated randomized clinical trials (RCTs), prospective or retrospective observational cohort studies, and case-control studies for inclusion in this study.

The sample size for the meta-analysis was 22,748 patients, representing 16 RCTs. In 15 of these trials, SMART was evaluated as a combination therapy with budesonide and formoterol in a dry-powder inhaler.

The researchers employed a random-effects model to determine risk ratios, risk differences, and mean differences with respective 95% confidence intervals.

Results showed that SMART was associated with a reduced risk of asthma exacerbations compared with the same dose of inhaled corticosteroids and LABA as the controller therapy (risk ratio [RR]: 0.68 [95% CI: 0.58 to 0.80]; risk difference [RD]: –6.4% [95% CI: –10.2% to –2.6%]). Furthermore, they found that SMART was associated with a reduced risk of asthma exacerbations when compared with a higher dose of inhaled corticosteroids and LABA as the controller therapy (RR: 0.77 [95% CI: 0.60 to 0.98]; RD: –2.8% [95% CI: –5.2% to –0.3%]).

Notably, the researchers observed similar results when SMART was compared with the sole use of inhaled corticosteroids as controller therapy.

Although the researchers found that the absolute RD in asthma exacerbation between SMART and a higher dose of inhaled corticosteroids and LABA as controller therapy was –12% in children aged between 4 and 11 years—compared with –2.8% in the older group—less data were available for the younger age group.

The researchers found minimal evidence of changes in symptom control in patients using SMART. They also found that SMART was not statistically linked to asthma-related quality of life, which was an outcome infrequently examined in the literature. Finally, the team found no significant association between SMART and changes in rescue medication use.

Although outside the scope of this review, the researchers wrote that one limitation of this study is that adverse events attributable to SMART were not evaluated. The researchers suggest that clinicians should consider known adverse effects and drug costs when prescribing SMART.

“In this meta-analysis of patients with persistent asthma,” conclude the authors, “the use of single maintenance and reliever therapy compared with inhaled corticosteroids as the controller therapy (with or without a long-acting β-agonist) and short-acting β-agonists as the relief therapy was associated with a lower risk of asthma exacerbations. Evidence for patients aged 4 to 11 years was limited.”

To read more about this study, click here.