ADHERENCE TO INSULIN IN SINGAPOREAN PEDIATRIC TYPE 1 DIABETES PATIENTS AND ITS IMPACT ON GLYCEMIC CONTROL AND HEALTHCARE UTILIZATION
Objective: Optimizing glycemic control is challenging with insulin nonadherence. This study aimed to characterize the prevalence of nonadherence among Singaporean pediatric patients with type 1 diabetes mellitus (T1DM) and investigate its associated outcomes.
Materials and methods: Singaporean patients with T1DM aged ≤18 years old with ≥1 year of insulin prescription between 2012 and 2016 were included in this retrospective, single-center longitudinal study. Patients on insulin pump were excluded. Nonadherence was defined as medication possession ratio (MPR) <100%. Glycemic control was defined using mean HbA1c within the study period. Healthcare utilization was defined as the number of outpatient, inpatient and emergency visits. The t-test, χ2 test, logistic regression and Poisson regression were used to analyze means, proportions, factors associated with nonadherence and association of nonadherence and healthcare utilization, respectively. Sensitivity analyses were performed for MPR thresholds of 80% and 95%.
Results: A total of 206 patients were included in this study. Nonadherent patients were older, had longer duration of diabetes since diagnosis and shorter duration of follow-up. Gender, race, financial class and number of concurrent medications were comparable between both groups. The prevalence of nonadherence was 34.0% (95% CI:27.9%–40.7%). Nonadherent patients had a higher average HbA1c (nonadherent:9.6%[2.1] vs adherent:8.6%[1.3], p<0.001). Nonadherence was not associated with healthcare utilization. Patients with >5 years of diabetes were more for likely to be nonadherent.
Conclusion: Nonadherence defined as MPR <100% is associated with poorer glycemic control. Further interventions may focus on patients with >5 years of diabetes to improve their adherence to insulin therapy.
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