For children with Idiopathic Short Stature (ISS) - a condition of unknown origin that causes kids to grow well below the normal height range - it would cost as much as $100,000 for one child to grow an average of 2 additional inches using growth hormone therapy for five years.

This finding comes from researchers at the University of Michigan C.S. Mott Children’s Hospital who analyzed the cost-effectiveness of growth hormone for children with ISS. They are the first to conduct such a study using clinical trial data that were the basis for the U.S. Food and Drug Administration’s July 2003 approval of recombinant growth hormone for the long-term treatment of children with ISS.

The study, appearing in the March issue of the Archives of Pediatric and Adolescent Medicine, revealed that the incremental cost-effectiveness of growth hormone therapy for ISS was more than $52,000 per inch.

In all, it would cost about $40 billion dollars to treat the estimated 400,000 American children ages 4 to 15 who are now eligible for growth hormone therapy under the ISS indication, says study lead author Joyce Lee, M.D., with the Division of Pediatric Endocrinology and Child Health Evaluation Research (CHEAR) Unit in the Division of General Pediatrics at U-M.

“Due to variability in the growth response we found in children with ISS, targeted treatment of children with ISS who have the greatest potential for growth is critical to improve the cost-effectiveness of this therapy,” says Lee.

Children with ISS represent the shortest 1.2 percent of all children based on age and gender. Since they are otherwise healthy children, there is considerable debate about the costs and benefits for a 1- to 2-inch height gain from hormone therapy.

With such a large group of children now eligible for growth hormone therapy, Lee says it was critical to reassess its cost-effectiveness based on the efficacy data used for the FDA approval, and also to evaluate the cost-effectiveness of alternative growth hormone treatment strategies for ISS.

To determine the cost-effectiveness of the therapy, Lee and her colleagues compared the height gain by adulthood for children treated for five years with growth hormone therapy to that of children who received no medical intervention.

The study focused on children with ISS who had no evidence of growth hormone deficiency or other known medical conditions that might compromise their growth.

Results revealed that the incremental cost-effectiveness of growth hormone therapy for ISS was approximately $100,000 per child, or $52,000 per inch - substantially higher than a previous cost estimate of $35,000 per inch.

Cost of the medication was a major factor in the cost-effectiveness estimates, notes Lee. For example, if the typical cost for the growth hormone was cut in half, the cost-effectiveness would be markedly lower, at $25,000 per inch.

“With the rising cost of prescription drug therapies in the country, growth hormone therapy for ISS has the potential to become one of the major challenges facing our health care system today,” says Lee.

To improve the cost-effectiveness of growth hormone therapy, Lee says more research needs to be done to help physicians identify children likely to have the greatest potential for growth.

Additionally, she stresses the need to have future research examine the psychological outcomes related to growth hormone therapy use.

Lee’s study solely focused on cost-effectiveness based on the outcome of height gain by adulthood. It did not evaluate the impact of growth hormone therapy on improvements to quality of life, or the possible long-term effects on salary and future earnings. Both are critical indicators for growth hormone therapy use, Lee says, and currently there is no research that demonstrates that it improves the quality of life for children with ISS.

Along with Lee, co-authors from the CHEAR Unit in the Division of General Pediatrics were Matthew M. Davis, M.D., MAPP; Sarah J. Clark, MPH; and Alex R. Kemper, M.D., MPH, MS; and Timothy P. Hofer, M.D., Veterans Affairs Health Services Research and Development at the VA Ann Arbor Healthcare System.

The study was supported by a Pediatric Health Services Research Training Grant from the National Institutes of Child Health and Human Development.

Reference: Archives of Pediatric and Adolescent Medicine, March 2006, Vol. 160, No. 3.