What Kinds of Studies Does Asthma Research Need?
MARCH 03, 2017
Elizabeth Matsui, MD, MHS, professor of pediatrics at Johns Hopkins University in Baltimore discussed what kinds of studies are needed in asthma during a presentation at the annual meeting of the American Academy of Allergy, Asthma, and Immunology (AAAAI 2017) in Atlanta, Georgia.
In 2008, a study conducted among AAAAI members from that year revealed that 75% of them reported emphasizing the importance of environmental control and 66% reported providing environmental control educational materials to their patients. However, a survey created by the US Environmental Protection Agency showed that only around 30% of patients or parents of pediatric patients implemented the recommendations in such “essential” materials.
Why is there such a discrepancy here? Skepticism on the part of patients or their caregivers plays a part in why trial results are difficult to translate to real-world clinical practice. “Adherence to medication in those studies are typically very high,” Matsui explained. However, there is limited evidence showing that randomized controlled trials (RCTs) translate to public health practice.
In Matsui’s eyes, asthma interventions aren’t tested well enough before starting a RCT. “I don’t think we have a good understanding of how they work,” she said.
There are unique challenges when it comes to conducting environmental RCTs. For efficacy to be accomplished, the measure being tested must reduce targeted exposures in the active treatment arm to a substantially greater degree than in the control arm. Crediting positive outcomes to a change in the home is difficult. Populations are often diverse between RCTs, and indoor and outdoor exposures can be difficult to track. These factors make it challenging to replicate studies to prove efficacy.
There are other issues with the populations recruited for studies. Those who agree to take part in the study may already be motivated to make changes to their home environment. Methods to reduce the risk of contamination and crossover can be expensive and difficult to implement.