Investigation of 2016 asthma child trial raises questions about placebos and treatment when control groups are used

Medical studies often rely on placebos — inactive treatments given to a control group so their experience can be compared with that of the group that was actually treated.

But are placebos always ethical?

That’s the question at the heart of Charles Piller’s in-depth investigation of a 2016 asthma trial and its counterparts in the world of medical research. The article, which appeared in Science, examines a federally funded trial in which University of Pittsburgh researchers looked into vitamin D’s relationship to childhood asthma. Researchers enrolled 400 participants, all asthmatic children with vitamin D deficiencies, most of whom were Black, and gave half of them high doses of vitamin D.

The other group got a placebo pill that did not treat vitamin D deficiency at all, even though the kids were at risk for bone fractures and other symptoms due to the deficiency.

“The children, as asthmatics treated with corticosteroids, already faced possible bone health problems and diminished growth,” Piller writes, “and any vitamin D deficiency would place them at greater risk for fractures.”

The trial was halted when the researchers found no clinical benefit from the supplements. Meanwhile nine bone fractures had occurred among participating children across both groups, and parents had not been informed of those risks.

The study “exemplifies the growing number of studies in humans that inappropriately reject control groups receiving ‘usual care’ — current best practice treatments used by doctors. In a hunt for compelling results, many researchers favor using sharply divergent treatment arms in a trial,” Piller writes.

The researchers, he says, called the risks miminal. “The placebo was justified because vitamin D testing is not routine, they argued. If not for the trial, the kids’ vitamin deficiency probably wouldn’t have been detected, so they were no worse off in the study,” he writes.

He investigates why researchers choose not to provide usual care, sometimes claiming a placebo constitutes such a treatment. And he untangles the thorny ethics of how studies are designed and carried out as well as how researchers obtain (or don’t obtain) informed consent from patients or their guardians.

The University of Pittsburgh’s Juan Celedón, who ran the vitamin D trial, told Piller the study “underwent rigorous review before and after it was funded.”

Piller paints an intricate picture of the whys behind the study design and the many issues — from racial justice to federal funding — such trials raise.

To read the story, visit bit.ly/sciencevitamind.