International Comparison of Time to Treatment Intensification and Rates of Complications in Metformin Monotherapy Treated Type 2 Diabetes Patients

• Author / Creator

  Dubois, Tyler

• Type 2 diabetes mellitus is a progressive disease which affects many people in Canada and the United States, and the prevalence of type 2 diabetes is only expected to increase in the future. Pharmacological interventions are a cornerstone of the management of type 2 diabetes as they help to attain substantial and sustainable lowering of a patient’s blood glucose levels. Moreover, they contribute to enhancing a patient’s overall quality of life by reducing complications throughout the duration of this disease. In practice, type 2 diabetes patients in both Canada and the United States are managed according to clinical practice guideline (CPG) recommendations, which involve the utilization of metformin as a first line antihyperglycemic agent to bring blood glucose levels to a target level. Subsequent treatment intensification with other antihyperglycemic agents, including insulin, is often required when a patient’s blood glucose is no longer under control. A lack of glucose control or untimely intensification of drug therapy for type 2 diabetes patients can lead to major complications.
  The first objective of this research program was to determine if differences exist between the way that newly treated type 2 diabetes patients are managed in Canada and the United States. This was accomplished using a retrospective cohort of type 2 diabetes patients from Canada and the United States who were just starting antihyperglycemic therapy. The study period was 2004-2010. To ensure comparability, the cohorts were restricted to patients initiating guideline-recommended metformin monotherapy treatment as directed by the CPGs in the two countries. We then determined the time from the initiation of guideline-concordant antihyperglycemic therapy to the addition of a second antihyperglycemic agent. The results showed that patients in the United States are more likely to intensify drug therapy sooner than patients in Canada and at a lower hemoglobin A1c value. This suggests that although CPGs are similar between Canada and the United States, adherence to the guidelines may be different between the two countries and patients in Canada may have more clinical inertia compared to their United States counterparts with respect to antihyperglycemic drug changes.
  The second objective was to determine if there are differences between Canada and the United States in terms of the time from the initiation of type 2 diabetes treatment to any major diabetes-related complications. In this study, we retrospectively determined the time from the initiation of guideline-concordant metformin monotherapy to the first occurrence of macrovascular and microvascular complications of interest. Our results show that, for the most part, there are minimal differences in rates of complications between the countries; however, patients in the United States have higher rates of coronary artery bypass graft (CABG) or percutaneous coronary intervention (PCI) compared to patients in Canada.
  
  Collectively, our studies suggest that even though patients in the United States are experiencing intensification of type 2 diabetes treatment sooner and at a lower hemoglobin A1c level, there is minimal difference in the time from initiation of treatment to the incidence of macro- or microvascular complications in our population. Historically, the clinical benefits of timely treatment intensification have been shown; however, newer clinical trials suggest that the benefits of intensification may not be substantial. Thus, although the United States intensified treatments more quickly, the minimal difference in rates of complications is in line with current evidence on the role of blood glucose on major macrovascular and microvascular complications.

• Subjects / Keywords

  • Pharmacoepidemiology
  • Metformin
  • Diabetes
  • Epidemiology
  • Complications

• Graduation date

  Fall 2018

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3GT5FX4S

• License

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