Mortality Certified as Diabetic Ketoacidosis Among Brazilian Children and Adolescents, 2015-2023: A National Time-Series Study of Trend and Cause-of-Death Coding Specificity

BackgroundDiabetic ketoacidosis (DKA) is a preventable metabolic emergency and an important cause of acute diabetes-related morbidity and death in youth.Contemporary national data describing fatal pediatric DKA in Brazil are scarce.We examined temporal trends and demographic and regional variation in DKA mortality among Brazilian residents aged 0-19 years. MethodsWe conducted a population-based time-series study using final, publicly available records from the Brazilian Mortality Information System for 2015-2023.Deaths were included when the underlying cause was DKA (International Classification of Diseases, 10th Revision codes E10.1, E11.1, E12.1, E13.1, or E14.1) and age at death was 0-19 years.Official age-, sex-, region-, and year-specific population estimates were used as denominators.Rates per one million person-years and exact Poisson 95% confidence intervals (CIs) were calculated.Temporal change was estimated using quasi-Poisson regression with log population as an offset. ResultsWe identified 709 DKA deaths during 541.98 million person-years (pooled rate, 1.308 per million personyears).Annual deaths increased from 48 in 2015 to a peak of 109 in 2021 and were 85 in 2023; rates were 0.767 (95% CI: 0.565-1.017) in 2015, 1.846 in 2021, and 1.473 (95% CI: 1.177-1.822) in 2023 per million.The average annual increase was 7.58% (95% CI: 3.66%-11.65%;p < 0.001), but a segmented model joining at 2021 fitted better: +12.52% per year (95% CI: 9.22%-15.91%) to 2021 and -10.12% per year (95% CI: -17.80% to -1.73%) thereafter.All diabetes deaths (E10-E14) increased more slowly (2.59%; 95% CI: 0.22%-5.01%),while the share coded with a ketoacidosis fourth character rose from 35.0% to 58.2%; decomposition attributed 88.9% of the 2015-to-2023 rise in DKA deaths to this coding change.The crude 2020-2023 versus 2015-2019 rate ratio (RR) was 1.40 (95% CI: 1.11-1.75),but 1.03 (95% CI: 0.68-1.55)after adjustment for the secular trend.Rates were highest at age 15-19 years (2.654 per million person-years) and lowest at age 5-9 years (0.487; RR: 5.45; 95% CI: 3.71-8.01).Females had higher mortality than males (RR: 1.38; 95% CI: 1.08-1.76).The Northeast had the highest regional rate and the South the lowest (RR: 1.74; 95% CI: 1.20-2.52).Most deaths occurred in hospitals (90.6%), and 59.2% were coded as DKA in unspecified diabetes (E14.1). ConclusionsMortality certified as DKA among Brazilian children and adolescents rose to a peak in 2021 and then declined, with marked age, sex, and regional variation.Most of the measured rise is consistent with more specific fourth-character coding rather than a proportional increase in diabetes deaths, and the 2020-2023 elevation is explained by the pre-existing trend rather than by a pandemic step change.These data cannot establish whether fatal ketoacidosis itself became more frequent; the high proportion of unspecified diabetes coding (E14.1)limits etiologic interpretation and is itself a surveillance finding.