A Decade of Disparities in Diabetes Technology Use and HbA1c in Pediatric Type 1 Diabetes: A Transatlantic Comparison

Abstract

Objective: As diabetes technology use in youth increases worldwide, inequalities in access may exacerbate disparities in hemoglobin A1c (HbA1c). We hypothesized that an increasing gap in diabetes technology use by socioeconomic status (SES) would be associated with increased HbA1c disparities.

Research design and methods: Participants aged <18 years with diabetes duration ≥1 year in the Type 1 Diabetes Exchange (T1DX, U.S., n = 16,457) and Diabetes Prospective Follow-up (DPV, Germany, n = 39,836) registries were categorized into lowest (Q1) to highest (Q5) SES quintiles. Multiple regression analyses compared the relationship of SES quintiles with diabetes technology use and HbA1c from 2010-2012 to 2016-2018.

Results: HbA1c was higher in participants with lower SES (in 2010-2012 and 2016-2018, respectively: 8.0% and 7.8% in Q1 and 7.6% and 7.5% in Q5 for DPV; 9.0% and 9.3% in Q1 and 7.8% and 8.0% in Q5 for T1DX). For DPV, the association between SES and HbA1c did not change between the two time periods, whereas for T1DX, disparities in HbA1c by SES increased significantly (P < 0.001). After adjusting for technology use, results for DPV did not change, whereas the increase in T1DX was no longer significant.

Conclusions: Although causal conclusions cannot be drawn, diabetes technology use is lowest and HbA1c is highest in those of the lowest SES quintile in the T1DX, and this difference for HbA1c broadened in the past decade. Associations of SES with technology use and HbA1c were weaker in the DPV registry.

© 2020 by the American Diabetes Association.

Figures

Figure 1

Pump use, CGM use, and HbA1c by SES in the DPV and T1DX registries in 2010–2012 and 2016–2018. A–F: Mean estimates by SES quintiles and time period from logistic (pump use, CGM use) and linear (HbA1c) regression models adjusted for sex, age, diabetes duration, SES, time period, minority status, SES-by–time period interaction, and SES-by–minority status interaction. G and H: Mean estimates with the regression model additionally adjusted for pump and CGM use. Dashed lines are connecting mean estimates for pump and CGM use or regression lines for HbA1c from models including SES as an ordinal term. From these models, P values for trend are given for the association with SES within each time period. Q1 is the lowest and Q5 is the highest SES quintile.

Figure 2

Effect of SES on insulin pump use, CGM use, and HbA1c. Effects of SES are slopes with 95% CIs of the regression lines for the dependent variables derived from multiple regression models including sex, age, diabetes duration, SES, time period, minority status, SES-by–time period interaction, and SES-by–minority status interaction, with SES modeled as an ordinal term. A positive value in insulin pump use and CGM use indicates higher use in quintiles of higher SES. A negative value in HbA1c indicates higher HbA1c in quintiles of lower SES. P values are given for the difference in effects of SES between the two time periods.