Adherence to insulin in children and young people with Type 1 diabetes

Introduction Type 1 diabetes is an autoimmune condition that results in the inability of the pancreas to produce insulin. The mainstay of treatment for this disease is administration of exogenous insulin. Adherence to this therapy is vital in avoiding both life-threatening short-term complications and life-limiting long-term complications. Despite its importance, it is an area that many children and young people struggle with. While there are a huge number of studies that attempt to identify individual factors affecting adherence, to date there have been no studies that attempt to draw these factors together into a single systematic review. Aims The aim of this project is to undertake a systematic review of insulin adherence in children and young people with T1DM, to understand what impact the factors studied have, and determine the areas that have/have not been researched with a view to guiding future research. Methods A systematic review was undertaken following a search of five medical databases aided by extensive training on optimising searches. The PICO framework was used to create inclusion/exclusion criteria that was used decide which studies to include in the review based on agreement of two reviewers. The key inclusion criteria stated that study participants must be humans, under the age of 18, with a diagnosis of T1DM and receiving insulin therapy. All study types that contained primary data were included. Included studies had relevant information entered into a data extraction tool, which could then be used to perform quality assessments and thematic analysis. Results One thousand three hundred and six studies were identified, of which 76 were included in the final analysis. Two hundred and thirty-six factors were assessed for association with adherence, using 38 different methods. Eleven factors were assessed by four or more studies. Age was the most commonly assessed factor (33 studies), followed by HbA1c/glycaemic control (20 studies), duration of diabetes (19 studies) and gender (15 studies). There were 210 factors (89%) that were only considered in a single study. 3 Overall, 9 969 children and young people have been included in studies assessing adherence to insulin (mean: 133, range: 28 to 1 028). Formal meta-analysis was not able to be performed due to the large number of different methods of measuring adherence, methods of data presentation and differences in populations studied. Amongst the factors that have been assessed by multiple studies, there were some that displayed good agreement between studies on the direction of the effect on insulin adherence. Increasing age, depression (in the child/young person) and smoking frequency showed good agreement between studies for decreased adherence. Higher self-efficacy, family support, exercise frequency, increased responsibility taken by the child, higher socio-economic status and better parent-child relationship showed good agreement between studies for improved insulin adherence. Factors were divided into overarching themes: demographics, past medical history, diabetes management, psycho-social or family dynamics. Factors assigned to the demographics theme were the most frequently assessed by multiple studies. The most commonly assigned theme was the psycho-social theme, though the vast majority (93.1%) of these factors were assessed by a single study. PENDANT Study This prospective cohort study was designed with the aim of assessing the correlation between disease severity at diagnosis with a variety of psycho-social outcomes with a view to exploring their relationship with later adherence to insulin therapy. Recruitment for the study was interrupted by the COVID-19 pandemic after two patients had entered the study. The findings of this initial recruitment phase and the systematic review will be used to improve the study going forwards. Conclusion Insulin adherence has been assessed in multiple studies, but the variety of methods and heterogeneous populations make comparisons difficult. Harmonising methodologies for assessing adherence to insulin would enable improved assessment of factors affecting adherence to this critical medication and lead to the identification of potential barriers to target to improve adherence in T1DM in the future. Future studies could aim to assess modifiable factors that are currently under-researched, while also aiming to assess adherence in a way that considers the complex nature of adherence to insulin therapy