Intuitiveness, ease of use, and preference of a prefilled growth hormone injection pen: a noninterventional, randomized, open-label, crossover, comparative usability study of three delivery devices in growth hormone-treated pediatric patients.

Abstract Background: Growth hormone (GH) is used to treat pediatric and adult GH deficiency (GHD) and growth failure in, among others, patients with Turner syndrome or children born small for gestational age. To improve treatment adherence, self-injection devices should be easy to learn, easy to use, and well accepted, especially in pediatric patients. Several GH pen devices are available, each with distinct features designed for specific patient needs. Objectives: This study compared injection time and intuitiveness of a prefilled test injection device (Norditropin FlexPro, Novo Nordisk A/S, Bagsvaerd, Denmark) with those of 2 commercially available durable injection devices (easypod, Merck Serono SA, Geneva, Switzerland; and Genotropin, Pfizer Inc, New York, New York) in GH-treated pediatric patients. Dose accuracy, application errors, intuitiveness, usability, device features, ease of learning, ease of use, and overall preference were also assessed. Methods: This noninterventional, randomized, openlabel, crossover study enrolled patients aged ≥10 to Results: Included in the study were 56 patients (mean [SD] age, 13.6 [2.1] years; 63% male; GHD, 44 patients; Turner syndrome, 3; born small for gestational age, 9): 30 in the intuitiveness group and 26 in the instruction group. In the intuitiveness group, the mean (SD) mock injection time was significantly shorter with FlexPro (47.0 [49.0] seconds) than with the easypod (219.2 [72.6] seconds; P P P P Conclusion: In this study, Norditropin FlexPro was associated with shorter injection times, higher dose accuracy, and greater intuitiveness, and was rated as easier to learn compared with the easypod and Genotropin devices.