Compliance to Growth Hormone Therapy in Children and Adolescents with Growth Hormone Deficiency and Turner Syndrome and Impact on Height Velocity: A Prospective Study

Abstract

Adherence to recombinant growth hormone (rGH) in children is necessary to ensure good treatment outcome. Reported non-compliance to rGH in children varied from 5-82% with little data involving Asian population. The objectives of this study are to evaluate the compliance of children and adolescents to rGH, effect of non-compliance on growth and factors affecting non-adherence. Methods: This is a prospective cohort study over 1-year aiming at all patients age less than 18 years old treated with rGH in our centre. Compliance was assessed from the number of returned medications and electronic record within device. Poor compliance was defined as utilised dose <86% prescribed (equivalent to missing injection ≥1 per week). Result: Thirty-four patients were recruited including 20 (59%) patients with GH deficiency and 14 (41%) with Turner syndrome. Poor compliance was noted in 35% of patients. Poor compliance in GHD patients was significantly associated with an older age (mean 12.55 ± 3.33 vs 9.28 ± 3.20 years old, p=0.038) and longer duration of treatment (mean 5.41 ± 3.0 vs 2.93 ± 2.18 years, p=0.046). Frequent reasons for missing doses were forgetfulness and inadequate medications. Participants with poor compliance had significantly reduced height velocity (HV) and HV standard deviation score (SDS) compared to those with good compliance (p<0.05). Conclusion: Poor compliance is more common in adolescents, those on longer duration of treatment and leads to significantly reduced height velocity. Regular monitoring throughout the course of rGH is important. Measures to improve compliance must address the underlying reasons.