Ease of use and acceptability of a new pen device for the administration of growth hormone therapy in pediatric patients: an open-label, uncontrolled usability test

Abstract

Background: Recombinant human growth hormone (GH) is used for the treatment of several conditions associated with growth retardation and metabolic dysfunction. These patients are typically diagnosed and treated from childhood, and treatment adherence in children might be problematic. To potentially improve treatment adherence in children who self-inject GH, it is important that devices for the administration of GH are simple to learn to use, simple to use, and well accepted by patients and their parents or guardians.

Objective: This study compared the usability and acceptability of the Norditropin FlexPro pen and NovoFine needles (Novo Nordisk A/S, Bagsvaerd, Denmark) for the administration of GH in pediatric patients with GH deficiency (GHD).

Methods: Patients aged 10 to <18 years with GHD and who were receiving daily treatment with selfinjectable GH were included in this open-label, uncontrolled usability test. Patients used the Norditropin FlexPro pen and NovoFine G32 needles to inject test medium into an injection pad; this test was repeated. For the assessment of patients' acceptance of the device, patients completed a 21-item questionnaire regarding pen performance before and during injection.

Results: Seventy patients participated in the study (mean age, 14 years; 67% male; 23% left-handed). No significant differences in demographic characteristics (age, sex, duration of treatment with GH, current device used, and left- or right-handedness) were found between boys and girls, younger and older children, or children who had been receiving short-term (months) or long-term (years) GH treatment. Sixty-eight patients (97%) rated attachment of the needle, priming the device, dialing up the dose, and reading the scale on the device as very easy or quite easy. A total of 99% of patients rated injection of their usual dose and of a 4-mg dose as very easy or quite easy, and pushing the dose button as very easy or quite easy as well as very comfortable or quite comfortable. All of the patients rated hearing the click while performing the injection as very easy or easy. Overall, 64% of patients indicated a preference for the Norditropin FlexPro pen over the device they were currently using.

Conclusions: In this preliminary usability test in pediatric patients, the Norditropin FlexPro pen was perceived as reliable and easy to use and was well accepted. There was also a high level of comfort that GH had been injected properly and that the correct dose had been delivered among the children and adolescents with GHD who participated in the study.