Growth Hormone Injection Log Analysis with Electronic Injection Device for Qualifying Adherence to Low-Irritant Formulation and Exploring Influential Factors on Adherence

INTRODUCTION: Although the treatment success of long-term growth hormone therapy (GHT) is dependent on maintaining patients’ adherence to treatment, marked variations in adherence levels among children with GHT (eg, 7–71% nonadherence) have been reported. Barriers to or promoters of GHT adherence have been discussed and investigated, and digital health technologies, such as electronic GH injection devices, may have the potential to assess adherence to GHT more accurately. Thus, we conducted a multicenter, retrospective cohort study using GH injection log analysis of an electronic GH device, GROWJECTOR(®)L, to qualify adherence and explore the factors influencing adherence. METHODS: This study enrolled 41 patients (median[range] age, 5.8[3.0 ~ 17.0] years) with short stature from nine Japanese medical institutions. The injection log data (12–48 weeks) were read by smartphones and collected into the data center through a cloud server. RESULTS: Although cumulative adherence rates remained higher than 95% throughout the observation period, five (12.2%) patients had low adherence (<85%). Subsequently, subgroup and logistic regression analyses for exploring factors affecting adherence revealed that self-selection of GH device and irregular injection schedule (ie, frequent injections after midnight) significantly affected adherence rate (p=0.034 and 0.048, respectively). In addition, higher rates of irregular injections significantly affected low adherence (median[range], 11.26[0.79 ~ 30.50]% vs 0.26[0.00 ~ 33.33]%, p = 0.029). DISCUSSION: Our study indicated that injection log analysis using an electronic GH device could detect irregular injection schedules due to a night owl or disturbance in lifetime rhythm affecting low adherence and had significant potential to encourage collaborative monitoring of adherence with healthcare providers and patients themselves/caregivers, along with growing autonomy and shared decision-making. Our study suggests the significance of narrative and personal approaches to adherence of patients with GHT and the usefulness of digital devices for such an approach and for removing various barriers to patient autonomy, leading to improvement and maintenance of adherence.