ESPE Abstracts

Background: Treatment for growth disorders requires daily injections of recombinant human growth hormone (r-hGH) over multiple years, and automated devices may help in this regard. The ability to adjust injection device settings, which are pre-set as default unless changed by healthcare professionals, may improve patient comfort and needle anxiety and thereby improve adherence.

Aim: To study the association between injection device settings and adherence in patients with growth disorders.

Methods: Adherence and device settings were extracted from the easypod™ connect ecosystem. Patients aged ≥2y and <19y with at least 6 months of adherence data were selected. Mean adherence was stratified by high (≥85%) versus intermediate/low (<85%) between 0-6 months of treatment. The factors for device settings were injection depth (4mm, 6mm [default], 8mm); injection speed (slow, medium [default], fast; selection of European data due to sample size); injection time (3-5 sec [5 sec, default], 6-15 sec); needle speed (slow, medium [default], fast; selection of European data due to sample size) and needle type (29G [default], 30G, 31G; selection of European and Asia Pacific data due to sample size). For each patient, most frequently used device settings were calculated between 0-6 months of treatment. Logistic regression analysis was applied with adherence as the dependent variable and device setting factor and age at treatment start (<13y, ≥13y) as independent factors. In addition, geographical region was added to the model to adjust for differences in clinical practice.

Results: Data were available for 9121 patients (<13y, n=7865; ≥13y, n=1256). Mean age (SD) at treatment start was 9.2y (3.3). Overall, the proportion of patients with high adherence was 89.5%. For patients aged <13y at treatment start, adherence was highest when the injection depth was 4mm, injection time was 6-15 sec, needle speed was slow, and needle type was 30G. For patients aged ≥13y at treatment start, adherence was highest when the injection depth was 6mm, injection time was 6-15 sec, needle speed was fast, and needle type was 31G. We found no association between injection speed settings and adherence.

Conclusion: In this observational study, we found that adherence to r-hGH therapy via an automated device was associated with age-specific device settings, with younger patients preferring shorter injection depth, slower injection speed, and smaller gauge needles. This is the first attempt to evaluate preferred injection settings associated with better adherence to daily r-hGH injections by an automated device using a large sample size.