BELT Asthma Study

Study Description and Methods

This large-scale multi-center project titled Blacks and Exacerbations on LABA v. Triotropium (BELT), a subcontract with Harvard University, is designed to compare the effectiveness of long-acting beta agonists (LABA)/inhaled corticosteroids (ICS) versus triotropium/ICS in African-American patients with moderate to severe asthma.

Specific Aims and Objectives

The specific aims of this project are to:
1. To determine, in a one year practice-based, real-world, randomized, prospective, parallel group, longitudinal comparative effectiveness trial with clinically important outcomes, whether in self-identified African American patients with asthma, treatment with LABA/ICS is superior to use of a non-β-adrenergic bronchodilator (tiotropium) combined with ICS (Tio/ICS).

2. To determine, in the context of this trial, whether in the 20% of self-identified African American patients with asthma bearing Arg16Arg of ADRB2, treatment with LABA/ICS is superior to use of a non-β-adrenergic bronchodilator combined with ICS.


This project was conducted from September 2010 through September 2013.


This project is currently conducting analysis.

Key Findings and Publications

The primary outcome for this study was time to asthma exacerbation, defined as a worsening asthma event requiring oral or parenteral corticosteroids. Among black adults with asthma treated with ICS, adding a LABA did not improve time to asthma exacerbation compared with adding tiotropium. These findings were not affected by polymorphisms at the Arg16Gly locus of ADRB2. These findings do not support the superiority of LABA + ICS compared with tiotropium + ICS for black patients with asthma.

Anticholinergic vs Long-Acting β-Agonist in Combination With Inhaled Corticosteroids in Black Adults With Asthma. The BELT Randomized Clinical Trial(11 page PDF). Wechsler ME, Yawn BP, Fuhlbrigge AL, Pace WD, Pencina MJ, Doros G, Kazani S, Raby BA, Lanzillotti J, Madinson S, Israel E. JAMA. 2015;314(16):1720-1730.

Contact Information

For additional information about this study, please contact:

Brian Manning, MPH, CHES
Associate Research Director
AAFP National Research Network
1-800-274-2237, x3179

This study was funded by a grant from the Agency for Healthcare Research and Quality.