Impact of social disadvantage on clinical and health care use indicators in adults with type 1 diabetes using insulin pumps in Ontario, Canada

Background — Social disadvantage is associated with worse diabetes outcomes among individuals with type 1 diabetes (T1D). Insulin pump therapy in the context of a publicly funded programme may mitigate the effects of social disadvantage on outcomes of diabetes. We investigated the effects of social disadvantage on health care use indicators and outcomes among pump users.

Methods — We conducted a population-based retrospective cohort study using administrative health data in Ontario, Canada. Adults with T1D who initiated pump therapy between 1 April 2012 and 30 March 2020 were included. Multivariable Poisson and linear regressions were used to evaluate associations between social disadvantage (defined by the material resources quintile of the Ontario marginalization index) and the following outcomes: health care use indicators (number of HbA1c tests and endocrinologist outpatient visits per year), and clinical outcomes (HbA1c and hospitalization/emergency department visits for hyperglycaemia and hypoglycaemia). All models were adjusted for age, sex, diabetes duration, baseline HbA1c, immigrant status, rural residence, diabetes physician specialty, clinic type and were estimated using generalized estimating equations (GEE) models to account for clustering by region.

Results — Among 15 755 adults with T1D who initiated pump therapy, 14% were from the most socially disadvantaged quintile. There were no associations between social disadvantage and health care use indicators. Individuals with greater disadvantage had poorer diabetes outcomes, including 0.12% higher HbA1c (95% CI 0.06–0.17) and a higher rate for hospitalization/emergency department visits for hyperglycaemia [adjusted rate ratio (aRR) 2.07 (95% CI 1.64–2.62)] and hypoglycaemia [aRR 1.76 (95% CI 1.41–2.19)] comparing the most versus least socially disadvantaged quintiles.

Conclusions — Social disadvantage was associated with worse clinical outcomes but not health care use indicators among pump users with T1D in Ontario. Social disadvantage remains a risk factor for poorer clinical outcomes among pump users, but pump use may sustain greater engagement with the diabetes care team.