Weekly pegylated recombinant human growth hormone for prepubertal children with growth hormone deficiency: adherence advantage drives superior short-term efficacy over daily rhGH

Background: Pediatric growth hormone deficiency (GHD) causes growth retardation due to insufficient pituitary growth hormone (GH) secretion. Conventional daily recombinant human growth hormone (rhGH) has low adherence due to frequent injections, impairing efficacy; weekly pegylated recombinant human growth hormone (PEG-rhGH) may improve adherence, but the mediating role of adherence differences in efficacy remains unclear. This study aimed to compare the 12-month efficacy and safety of weekly PEG-rhGH versus daily rhGH in prepubertal children, and to determine whether objective (injection completion rate) and subjective (Beliefs about Medicines Questionnaire) adherence mediate the efficacy difference. Methods: A single-center retrospective cohort study was conducted in the Department of Endocrine, Genetic, and Immunology, Children's Hospital of Xinjiang Uygur Autonomous Region (January 2020-December 2023). A total of 148 eligible prepubertal GHD children were enrolled, including 85 in the PEG-rhGH group (0.2 mg/kg/week, weekly injection) and 63 in the rhGH group (0.03 mg/kg/day, daily injection). Baseline characteristics were compared between the two groups. Adherence was evaluated by injection completion rate (ICR) (objective) and Beliefs about Medicines Questionnaire (BMQ, subjective). The primary efficacy indicator was 12-month change in height standard deviation score (△Ht-SDS), and the secondary indicator was 12-month height velocity (HV). The Hayes PROCESS macro (5,000 Bootstrap resamplings) was used to test the mediating effect of adherence. Results: 3.32±0.70, P