The National Institutes of Health (NIH) has conducted a study comparing three common approaches to periodically adjust the dosage of inhaled corticosteroids (ICS) for people with mild asthma found no detectable differences in how often a person's asthma worsened. The methods examined in this study were a patient-guided modification based on symptoms, an assessment made by an examining physician, or the results of a breath test to measure inflammation.

This NIH-funded study of adults with mild asthma, termed the Best Adjustment Strategy for asthma in the long term, or BASALT, appeared in the Journal of the American Medical Association.

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. It would not, however, eliminate the need for physician involvement. Patients in the study had physician visits every two to six weeks to ensure that their asthma was not worsening.

"We know daily inhaled corticosteroids work well in controlling asthma long term, but asthma control can change within short periods of time - with seasons, for example. Also, many patients with mild asthma are reluctant to take daily medication," said James Kiley, director of the Division of Lung Diseases at the National Heart, Lung and Blood Institute (NHLBI). "Finding a patient-directed method for adjusting inhaled corticosteroid therapy may allow patients with mild asthma to use inhaled corticosteroids only when their symptoms change."

The BASALT investigators divided 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.

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 night time 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.

"This study underscores the importance of research to examine treatment options. The study revealed findings that can be considered along with other studies to determine appropriate recommendations for treating mild asthma," said Dr Kiley.

NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases.