MADISON-People who use corticosteroids every day to control mild asthma do no better than those who use them only when they have symptoms, according to a recent study conducted in part by researchers at University of Wisconsin School of Medicine and Public Health.
The study, funded by the National Institutes of Health (NIH), compared three approaches commonly used to periodically adjust the dosage of inhaled corticosteroids (ICS) for people with mild asthma. The researchers found no detectable differences among the groups in how often a person's asthma worsened. The methods examined in the study were patient-guided modification based on symptoms, an assessment made by an examining physician, or the results of a breath test to measure inflammation.
The lack of detectable differences in treatment failure-or in other clinical measures considered important for patients with asthma-suggests that a patient-directed approach to adjusting ICS dosage may be an option for treating mild asthma.
"Our study suggests that using a patient-directed method for adjusting inhaled corticosteroid therapy may allow patients with mild asthma to use the medication only when needed, instead of every day," said Dr. Robert Lemanske, head of the division of pediatric allergy, immunology and rheumatology at the UW School of Medicine and Public Health. "In addition to lessening the burden on patients of taking daily medication, this treatment approach could also minimize the risk of side effects and potentially reduce health care costs."
The results of the study, called the "Best Adjustment Strategy for Asthma in the Long Term," or BASALT, appears in the Sept. 12 Journal of the American Medical Association. University of Wisconsin Hospital and Clinics was one of 10 academic medical centers to participate in the study.
Lemanske and his fellow researchers divided the 342 participants (aged 18-70 with mild asthma) into three groups. Participants in the physician-assessment based adjustment group visited their doctors every six weeks and had their dosage (number of ICS puffs) adjusted based on published guidelines. Participants in the biomarker-based adjustment group also went to their doctors every six weeks, but ICS dose was adjusted based on the results of a breath test to measure nitric oxide, which reflects the level of inflammation in the airways. Finally, those in the symptom-based adjustment group were told to use ICS only when they had to use their short-acting bronchodilator for quick relief.
"This study underscores the importance of research to examine treatment options," said James Kiley, director of the division of lung diseases at the National Heart, Lung and Blood Institute (NHLBI). "The study revealed findings that can be considered along with other studies to determine appropriate recommendations for treating mild asthma."
The investigators monitored the participants for nine months, measuring several aspects of asthma control. The time to treatment failure, or worsening asthma, was the primary outcome measure. Other outcomes monitored during the study included lung function, days missed from school/work, frequency of daytime and nighttime symptoms, and overall asthma-control scores.
A few of the 18 secondary outcomes showed slight statistical differences for one of the three approaches. For example, the biomarker group had a slightly higher rate of days missed from work or school, though overall numbers were quite low (0.46 days/year for biomarker group vs. 0.25 for physician group and 0.11 for symptom based group). Only the cumulative dosage of ICS taken showed any striking difference. The people in the symptom-based group inhaled half as much ICS as in either of the other two groups.
The study was supported by NHLBI grants U10 HL074225, U10 HL074227, U10 HL074231, U10 HL074204, U10 HL074212, U10 HL074073, U10 HL074206, U10 HL074208, and U10 HL074218. More information about this trial (NCT00495157) can be found at ClinicalTrials.gov.