The study, conducted by a team at the University of Texas Medical Branch (UTMB), tested 340 patients with mild to moderate asthma over a nine month period.
One group took corticosteroids – the most common treatment for asthma – under the normal twice-a-day prescription, and the other only when symptoms occurred.
The researchers found that symptom-based doses are not only just as effective as taking a daily inhaler, but that the delivery method was actually an improvement in some instances, such as in the fall when autumnal allergies and more exposure to viral infections serves to irritate the condition.
Speaking on a UTBM video about the project, lead researcher William Calhoun said: “We found in the fall – the time when many asthma exacerbations occur – using the symptom based adjustment using steroids when symptoms occur resulted in fewer exacerbations.”
The study – published in tomorrow's Journal of the American Medical Association (JAMA) – also found that the condition could be kept under control using half the usual recommended dose of inhaled steroids when the treatment-if-needed approach was used.
Furthermore, Calhoun believes that in the long-term lesser dosages of inhaled corticosteroids (ICS) could reduce the side-effects associated with the therapy, including cataracts, problems with vocal cords and oral yeast infections.
"The discovery that these two courses of treatment do not differ significantly could eventually change the way doctors and patients manage asthma, providing an option that is easier to follow and possibly less expensive," he said, adding that in America alone, the inhaled steroid industry provides drugs to 25m people at an average cost of $3,300 per year.
He also said for lower-income communities – such as emerging markets – the finding could be particularly valuable as less medication is needed for successful treatment.
For the regulators, he also said that improved patient compliance could be boosted because the treatment option is “easier to follow”.