Asthma patients reported that placebo treatments were as effective as real medicine in relieving their wheezing and coughing, even though an objective breathing test showed that only the medicine significantly opened their airways, a new study has found.
The study, published today in the New England Journal of Medicine, not only illustrates the power of the placebo effect, but also shows that patients may not be a reliable source of objective information about the effectiveness of medications and other treatments.
For the study, researchers at Harvard Medical School gave 39 individuals with mild to moderate asthma four different interventions: an albuterol inhaler (a standard treatment for asthma), a placebo inhaler, sham acupuncture (a fake acupuncture treatment in which needles are used but not on any known acupuncture points), and no treatment at all (patients were told to wait for a few hours and then go home). All four interventions were randomly assigned to each patient during 12 separate visits spaced three to seven days apart.
Immediately before and after each treatment session the patients were given a breathing (spirometry) test to measure their lung function. They were also asked to assess their symptoms.
The objective breathing test found that the albuterol inhaler improved the patients’ lung functioning (their ability to exhale) by an average of 20 percent. It also found that lung function improved about 7 percent after all the other interventions, including no treatment at all.
But something strikingly different happened regarding the patients’ perceptions of their symptoms. They reported a 50 percent improvement in their symptoms with the albuterol inhaler, a 45 percent improvement with the placebo inhaler and a 46 percent improvement with the sham acupuncture — findings that are not statistically different.
In fact, even after the non-treatment visits, the patients reported a 21 percent improvement in their symptoms.
“The placebo effects were equivalent to the drug effect,” the study’s authors concluded.
These findings suggest — as other research has before on such varied illnesses as depression and low back pain — that the experience of receiving medical care can in itself help relieve pain and other symptoms.
Making sense of it all
The authors of the NEJM study make a couple of practical recommendations in their study’s conclusion. They suggest that doctors test the lung function of their asthma patients to determine how well they are doing rather than just rely on the patients’ self-assessments of their symptoms. They also advise researchers to be wary when conducting clinical trials on treatments for asthma or any other illness.
Patient self-reports, they say, are “unreliable” evidence that a treatment is actually effective.
But Daniel E. Moerman, professor emeritus of anthropology at the University of Michigan and long-time placebo effect researcher, wonders if this is the right interpretation of the study’s findings. Perhaps the medical community should be using these findings to reevaluate what medical treatments are supposed to be accomplishing.
“It is the subjective symptoms that brought these patients to medical care in the first place,” Moerman writes in an editorial accompanying the NEJM study. “They came because they were wheezing and felt suffocated, not because they had a reduced FEV [a measurement of lung capacity]. The fact that they felt improved even when their FEV had not increased begs the question, What is the more important outcome in medicine, the objective or the subjective, the doctor’s or the patient’s perception? This distinction is important, since it should direct us as to when patient-centered versus doctor-directed care should take place.”
FYI: Two of the authors of the NEJM study have extensive ties to pharmaceutical companies, including companies that market albuterol drugs. The study itself was funded by the National Center for Complimentary and Alternative Medicine, which is part of the National Institutes of Health.