Impact of deprivation, ethnicity, and insulin pump therapy on developmental trajectories of diabetes control in COB type 1 diabetes.

BACKGROUND: There is marked variation in diabetes outcomes for children and adolescents across the UK. We used modelling techniques to examine the independent contributions of deprivation, ethnicity, insulin pump use, and health service use on HbA1c trajectories across adolescence.

METHODS: Prospective data from a large UK Paediatric & Adolescent Diabetes Service on subjects with type 1 diabetes (T1D) aged 9-17 years from January 2008 to December 2013: 2560 HbA1c datapoints were available on 384 patients [193 (50.4%) female]. Sequential multilevel growth models assessed the effects of sex, duration of diabetes, deprivation, ethnicity, insulin pump use, and health service use on HbA1c . Growth mixture models were used to identify discrete HbA1c trajectories across adolescence.

RESULTS: Mean clinic HbA1c decreased from 2008 to 2013 by 0.122% (95% confidence interval: 0.034, 0.210; P = .007) per year. The optimal multilevel growth model showed mean HbA1c increased with age (B = 0.414, P < .0001), and that mean HbA1c was predicted by white/British ethnicity (B = -0.748, P = .004), clinic visits (B = 0.041, P = .04), and pump use (B = -0.568, P < .0001) but not deprivation. The optimal mixture model was a four trajectory group solution, with 45.1% in Good Control, 39.6% with Deteriorating Control, 6.5% with Rapidly Deteriorating Control, and 8.8% in Poor Control across adolescence. Only pump use predicted trajectory group membership, being protective against membership of all other trajectories compared with Good Control.

CONCLUSIONS: Increasing uptake of insulin pumps and ensuring access to health services are likely to be the most effective means of reducing inequalities in outcomes of T1D in children and young people.