Asthma Clinical Research Network (ACRN) Trial - Best Adjustment Strategy for Asthma in Long Term (BASALT)

Asthma is a common, long-term disease that is caused by inflammation of the airways. Symptoms of asthma may include wheezing, coughing, shortness of breath, and chest tightness. The most common treatment for asthma is the use of inhaled corticosteroid medications with periodic adjustments to treatment intensity. For example, corticosteroid dosage is increased when asthma symptoms worsen and decreased when symptoms improve. However, guidelines for making these adjustments, especially reduced intensity adjustments, have not been well established. In people who are initially well controlled on daily low-dose inhaled corticosteroid therapy, symptom-based adjustment (SBA) and/or biomarker-based adjustment (BBA) of inhaled corticosteroid therapy may be more beneficial at maintaining asthma control than standard, guideline-based adjustments (GBA). The purpose of this study is to determine if adjusting treatment based on symptoms and/or lung function biomarkers is more effective at controlling asthma than adjusting corticosteroid use based on standardized medical guidelines.

This study begins with a 4-week period during which participants are monitored while they use an inhaler containing a low dose of inhaled corticosteroid medication. Participants then are assigned to take part in either the BASALT study or the Tiotropium as an Alternative to Long-Acting Beta-Agonists and Corticosteroids (TALC) study, which is a separate Asthma Clinical Research Network (ACRN) study. Participants in BASALT undergo 2 to 4 weeks of adherence testing, which involves using three inhalers that have electronic monitoring devices attached to them. Participants also are asked to measure and record their breathing rates and lung function in a study diary.

BASALT participants are then randomly assigned to one of three treatment groups: SBA, BBA, or GBA. Each participant is given four inhalers: one inhaler contains albuterol, which is used on an as-needed basis as rescue medication; one inhaler contains corticosteroid medication; and two inhalers contain placebo. One of the latter three inhalers is used each time the albuterol inhaler is used, and the other two inhalers are used on a daily basis. Study visits occur at Weeks 2, 4, 6, 12, 18, 24, 30, and 36 of the treatment period. Inhalers are adjusted during these visits based on SBA, BBA, or GBA guidelines. At selected visits, the following procedures occur: physical exam; blood collection; allergy skin testing; heart rate monitoring; lung function and airway testing; methacholine challenge test to determine asthma severity; and questionnaires to assess asthma control, quality of life, and other healthcare factors. Participants record asthma symptoms, peak flow measurements, and medication usage in a daily diary.