Aims: To describe and compare changes in glycaemic control in young people with Type 1 diabetes over time between the last 2 years in paediatric care and the first 2 years in adult care and to identify risk factors for poor glycaemic control.

Methods: Our retrospective cohort study followed participants aged 14–22 years from 2 years before to 2 years after transfer from paediatric to adult care. Changes in glycaemic control were calculated using repeated measurements. We adjusted for gender, age at diabetes onset, age at transfer, duration of diabetes at transfer, gap (amount of time) between last paediatric and first adult visit, comorbidity, learning disability and/or mental health conditions and family structure. We examined associations between acute hospital admissions, low visit attendance rate, loss to follow-up and baseline HbA1c level.

Results: Among 126 participants, the mean HbA1c level was 80 mmol/mol (9.4%) pre-transfer but decreased by an average of 3 mmol/mol (0.3%) each year post-transfer (P = 0.005). Young people with a learning disability and/or a mental health condition had worse glycaemic control (P = 0.041) and the mean HbA1c of those with divorced parents was 14 mmol/mol (1.2%) higher (P = 0.014). Almost one-third of participants were admitted to the hospital for acute diabetes care. Low visit attendance rate, high baseline HbA1c level, learning disability and/or mental health conditions and divorced parents predicted acute hospital admissions.

Conclusions: Glycaemic control improved significantly after transfer to adult care, but the mean HbA1c level remained high. Future interventions should focus on young people with divorced parents, those with a learning disability and/or mental health condition and those who do not attend clinical visits to improve HbA1c levels and thereby reduce hospitalization rates.