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When it comes to treating very short kids with growth hormone, some doctors may be just as swayed by their own attitudes about being short as by data, suggests a new study.

The authors found that many doctors would keep treating kids with growth hormone, and often increase their doses, if the kids still didn't grow much after a year on the treatment - especially when the doctors had strong feelings about how being short affects a kid's emotional well-being. The pattern was especially true for very short boys.

"What parents hear as medical advice may be little more than a doctor's own cultural assumptions," Susan Cohen, a journalist and the author of Normal at Any Cost, told Reuters Health. "They seem to think it's such a tragedy to be an extremely short boy."

Most doctors agree that kids who are low on growth hormone - a protein produced by the pituitary gland - should be treated. What's more controversial is what to do with the kids who have normal levels of growth hormone, but are still in the shortest 1.2 percent of kids their age, which qualifies them for treatment under Food and Drug Administration (FDA) guidelines.

Some researchers say these kids should be treated, if only for the chance to avoid the teasing and embarrassment that often comes with being the shortest kid in school; others argue that doctors could be unnecessarily putting kids at risk by treating them - and say that short kids generally turn out okay anyway.

Treatment with growth hormone costs about $22,000 a year, the authors say - which might or might not be covered by insurance. With as many as 500,000 children in the U.S. meeting FDA criteria for the treatment, the drug has a potential market in excess of $10 billion, they add.

Led by Dr. J. B. Silvers of Case Western Reserve University, the study authors surveyed 656 pediatric endocrinologists on how they would treat different hypothetical kids who were very short but didn't have a deficiency in growth hormone or another clear medical condition. For each case, they presented doctors with factors including a kid's gender, current height, projected adult height, and whether or not the family wanted growth hormone treatment. Doctors were asked if they would start that kid on growth hormone.

Then, the researchers gave the doctors more options: one year later, here's how much that kid grew, and here's how the family now feels about growth hormone. Do you stop treatment, continue with the same treatment, or up the dose?

When deciding whether or not to start a child on growth hormone, doctors generally answered in line with current FDA guidelines. But when it came to kids who barely grew after a year on growth hormone, many rejected conventional recommendations, which say treatment should be stopped if a kid grows less than 2 centimeters a year.

When the doctors were presented with a case of a kid who grew 1 cm in a year on growth hormone, 60 percent of them recommended upping the dose, 14 percent thought it should be kept the same, and 26 percent voted for stopping treatment. Doctors were more likely to keep kids on growth hormone when the kids had been shorter to begin with, when families still wanted treatment, and when they themselves believed that being very short takes an emotional toll on kids.

More than 1 in 4 of the doctors also responded that growth hormone has a positive impact on very short kids, even if it ends up having no major effect on their adult heights.

Cohen, who was not involved with the study, called that finding "astounding."

"You have to remember that these are healthy kids," she said. "The long-term risks of giving a child who already has normal levels of growth hormone more are not known. It is an experiment."

Dr. Leona Cuttler, one of the study's authors who is chief of endocrinology and diabetes as well as director of the Center for Child Health & Policy at Rainbow Babies & Children's Hospital in Cleveland, said that collectively, doctors' decisions to continue or to stop medicating kids have a huge impact on growth hormone use overall. "The decisions ... affect so many children at potentially high costs," she told Reuters Health.

Dr. Paul Saenger, a pediatrics professor at the Albert Einstein College of Medicine who was not involved with the study, said that regardless of doctors' own thoughts about being short, in the real world decisions about starting or continuing growth hormone are usually made by the family. In some cases, "the patient just says, 'I don't want it anymore,'" he told Reuters Health. "I think that a lot of it is driven by the interplay of physician and parent and patients, which is very complex."

Both doctors and parents can be influenced by drug companies who push the message that it's a medical problem for a kid to be very short, Cohen said. But, "height is only one thing about us," she cautioned, and research shows that these kids don't grow up with more psychological issues than other kids.

She says the right question to be asking parents of very short kids should be: "how much risk are you willing to take with a healthy child for what may be a few extra inches or may be really nothing at all?"