Studies on psychosocial effects after GH treatment for short stature exhibit bias
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Studies reporting on psychological outcomes after growth hormone treatment for short stature in children include a high risk for bias, in part due to a failure to mask participants in most randomized trials and a failure to control for potential confounding factors, according to a systematic review in The Journal of Clinical Endocrinology & Metabolism.
“Findings from the current methodological review suggest that much of this clinical research literature is rife with risk of bias,” Melissa Gardner, of the department of pediatrics and communicable diseases, and the child health evaluation and research unit at the University of Michigan, and colleagues wrote. “This may explain the variability of findings for these outcome variables across studies. Consequently, these studies should not be used for establishing either the psychological risks or benefits of GH treatment for [short stature].”
Gardner and colleagues analyzed data from 80 studies published between 1954 and 2014 (27 randomized study designs) in which researchers administered GH for the management of short stature in children and assessed psychosocial, cognitive, academic or health-related quality-of-life outcomes. Studies reviewed included 37 reporting on children with GH deficiency, 19 reporting on children with idiopathic short stature and 15 reporting on children with Turner’s syndrome. Researchers used the Cochrane Collaboration’s tool for assessing risk of bias in all studies.
Researchers found that 73 of the studies rated at high risk for bias; seven studies were rated “unclear” for bias; none of the studies rated as having a low risk for bias.
Listed shortcomings in randomized studies included a failure to mask participants and inadequate sequence generation and allocation concealment. For nonrandomized studies, shortcomings included a failure to control for potential confounding factors, failure to mask participants and additional problems in addressing incomplete outcome data and selective reporting of results.
“A common confounding factor was cointervention: several studies used GH in conjunction with other medications making it impossible to separate out effects of GH from those of the other medication alone or possible interactions,” the researchers wrote.
They also cited industry sponsorship, noted in two-thirds of the randomized studies and in one-third of the nonrandomized studies.
“The rationale for treatment rests on evidence that GH treatment is associated with improvements in various psychological outcomes,” the researchers wrote. “The findings of the current systematic review, however, undermine this rationale by showing weaknesses in methodological soundness of these studies and associated high risk of bias.” – by Regina Schaffer
Disclosure: The researchers report no relevant financial disclosures.