Rising Rates and Widening Socioeconomic Disparities in Diabetic Ketoacidosis in Type 1 Diabetes in Scotland: A Nationwide Retrospective Cohort Observational Study

Abstract

<b>Objective</b> - Whether advances in the management of type 1 diabetes are reducing rates of diabetic ketoacidosis (DKA) is unclear. We investigated time trends in DKA rates in a national cohort of individuals with type 1 diabetes followed for 14 years, overall and by socioeconomic characteristics. <p><b>Research Design and Methods</b> - All individuals in Scotland who were alive with type 1 diabetes and at least one year old between 2004-01-01 and 2018-12-31 were identified using the national register (N=37939). DKA deaths and hospital admissions were obtained through linkage to Scottish national death and morbidity records. Bayesian regression was used to test for DKA time trends and association with risk markers, including socioeconomic deprivation.</p> <p><b>Results</b> - 30427 DKA admissions, and 472 DKA deaths were observed over 393223 person-years at risk. DKA event rates increased over the study period (IRR per year=1.058 [1.054-1.061]). Males had lower rates than females (IRR Male:Female=0.814 [0.776-0.855]). DKA incidence rose in all age groups other than 10-19 year-olds, in whom rates were the highest but fell over the study. There was a large socioeconomic differential (IRR least:most deprived quintile=0.446 [0.406-0.490]) which increased during follow-up. Insulin pump use or completion of structured education were associated with lower DKA rates, antidepressant and methadone prescription were associated with higher DKA rates.</p> <p><b>Conclusion</b> - DKA incidence has risen since 2004, except in 10-19 year olds. Of particular concern are the strong and widening socioeconomic disparities in DKA outcomes. Efforts to prevent DKA, especially in vulnerable groups, require strengthening.</p>