Glycemic control and diabetes-related health care costs in type 2 diabetes; retrospective analysis based on clinical and administrative databases

Luca Degli Esposti,¹ Stefania Saragoni,¹ Stefano Buda,¹ Alessandra Sturani,² Ezio Degli Esposti<sup>1

1</sup>CliCon Srl, Health, Economics and Outcomes Research, Ravenna, Italy; ²Nephrology and Dialysis Unit, Santa Maria delle Croci Hospital, Ravenna, Italy

Background: Diabetes is one of the most prevalent chronic diseases, and its prevalence is predicted to increase in the next two decades. Diabetes imposes a staggering financial burden on the health care system, so information about the costs and experiences of collecting and reporting quality measures of data is vital for practices deciding whether to adopt quality improvements or monitor existing initiatives. The aim of this study was to quantify the association between health care costs and level of glycemic control in patients with type 2 diabetes using clinical and administrative databases.
Methods: A retrospective analysis using a large administrative database and a clinical registry containing laboratory results was performed. Patients were subdivided according to their glycated hemoglobin level. Multivariate analyses were used to control for differences in potential confounding factors, including age, gender, Charlson comorbidity index, presence of dyslipidemia, hypertension, or cardiovascular disease, and degree of adherence with antidiabetic drugs among the study groups.
Results: Of the total population of 700,000 subjects, 31,022 were identified as being diabetic (4.4% of the entire population). Of these, 21,586 met the study inclusion criteria. In total, 31.5% of patients had very poor glycemic control and 25.7% had excellent control. Over 2 years, the mean diabetes-related cost per person was: €1291.56 in patients with excellent control; €1545.99 in those with good control; €1584.07 in those with fair control; €1839.42 in those with poor control; and €1894.80 in those with very poor control. After adjustment, compared with the group having excellent control, the estimated excess cost per person associated with the groups with good control, fair control, poor control, and very poor control was €219.28, €264.65, €513.18, and €564.79, respectively.
Conclusion: Many patients showed suboptimal glycemic control. Lower levels of glycated hemoglobin were associated with lower diabetes-related health care costs. Integration of administrative databases and a laboratory database appears to be suitable for showing that appropriate management of diabetes can help to achieve better resource allocation.

Keywords: diabetes mellitus, glycemic control, HbA_1c, health expenditure