Equity of Continuous Glucose Monitoring in Children and Young People With Type 1 Diabetes: A Systematic Review

Background: Socioeconomic status (SES) and ethnic inequalities in type 1 diabetes (T1D) outcomes are well-established. There is concern that unequal access to technologies, including continuous glucose monitoring (CGM), may increase disparities. This systematic review summarises the evidence for inequalities in the prevalence of CGM use for children and young people (CYP) and outcomes for CGM users. Methods: Medline, Embase and Web of Science were searched for observational studies published between January 2020 and July 2023 which report CGM use stratified by any PROGRESS-Plus criteria for T1D patients under 26. Reports based in low- or middle-income countries, ≤500 participants or only reporting hybrid closed-loop systems were excluded. Primary outcomes were the proportion of patients using CGM and HbA1c of CGM users. Quality assessment was performed using the Newcastle-Ottawa Scale. Unadjusted odds ratios were calculated from the extracted summary data, though heterogeneity precluded meta-analysis. The protocol was preregistered with PROSPERO (CRD42023438139). Results: Of the 3369 unique studies identified, 27 met the inclusion criteria. Thirty-three percent were of 'good' or 'very good' quality. We found decreased CGM use and higher discontinuation for low SES, low education, publicly insured and minority ethnic, especially Black, CYP. These associations were generally robust to adjustment for other sociodemographic variables, suggesting an independent effect. Lower SES inequalities were seen in countries where CGM is reimbursed. Although low SES and minority ethnicity were associated with poorer outcomes in general, for CGM users there was no significant association between domains of disadvantage and higher HbA1c, excepting parental education. Conclusions: There are significant SES, ethnic and education inequalities in CGM use for CYP with T1D, particularly when reimbursement is limited. This inequity is contributing to inequalities in T1D outcomes. However, evidence suggests CYP benefit equally from CGM use, irrespective of ethnicity and SES. Increasing CGM funding and use is likely to reduce outcome inequalities.