Non-compliance with growth hormone treatment in children is common and impairs linear growth

Abstract

Background: GH therapy requires daily injections over many years and compliance can be difficult to sustain. As growth hormone (GH) is expensive, non-compliance is likely to lead to suboptimal growth, at considerable cost. Thus, we aimed to assess the compliance rate of children and adolescents with GH treatment in New Zealand. Methods: This was a national survey of GH compliance, in which all children receiving government-funded GH for a fourmonth interval were included. Compliance was defined as ≥85% adherence (no more than one missed dose a week on average) to prescribed treatment. Compliance was determined based on two parameters: either the number of GH vials requested (GHreq) by the family or the number of empty GH vials returned (GHret). Data are presented as mean ± SEM. Findings: 177 patients were receiving GH in the study period, aged ± 12.160.6 years. The rate of returned vials, but not number of vials requested, was positively associated with HVSDS (p≤0.05), such that patients with good compliance had significantly greater linear growth over the study period (p≤0.05). GHret was therefore used for subsequent analyses. 66% of patients were non-compliant, and this outcome was not affected by sex, age or clinical diagnosis. However, Maori ethnicity was associated with a lower rate of compliance. Interpretation: An objective assessment of compliance such as returned vials is much more reliable than compliance based on parental or patient based information. Non-compliance with GH treatment is common, and associated with reduced linear growth. Non-compliance should be considered in all patients with apparently suboptimal response to GH treatment. © 2011 Ren et al.