Utilization Of Oral Anti-diabetic Medications: Examining Adherence To Clinical Guidelines

The American Diabetes Association published a treatment algorithm for first line and second line drug therapy as a guide for physicians in treatment of type 2 diabetes mellitus. The level of concordance between clinical practice and the ADA guidelines has not been investigated. The effect of lab based evidence - impaired renal and liver function on physician prescribing behavior is not known. The aim of this study was to determine the degree of compliance of physician practice with the ADA guidelines and assess factors influencing these decisions. A retrospective cohort study of patients with diabetes managed at one of the clinics that provide routine diabetes care in University of Illinois Medical Center at Chicago was conducted for period from January 2007 to October 2010. Patients newly starting drug therapy were included in the study. Data from electronic prescription medication orders, laboratory data including serum creatinine, creatinine clearance, alanine aminotransferase, aspartate aminotransferase and hemoglobinA1c levels were used in the study. Patient demographics and all diagnosis data were also collected. Descriptive analysis of the data showed that physicians at UIMCC were compliant with the ADA guidelines about 72% of the time when they prescribed metformin as first line therapy adjusting for any liver or renal impairment status of the patient. The next most widely used drug as first line therapy was sulphonylureas followed by Insulin. A mixed effect regression model to identify predictors for prescribing metformin demonstrated that renal function, type of clinic and hemoglobin A1c levels were statistically significant variables. Patients with impaired liver function never got metformin. Patients with impaired renal function and higher haemoglobinA1c levels were less likely to receive metformin. Patients seen at the family medicine clinic were more likely to receive metformin than those seen at internal medicine or geriatric clinic. This single site study is the first to document the compliance of physicians with the ADA guidelines and assess the effects of patient’s clinical condition on prescribing behavior. It shows that physicians consider label information in their decision making process. Understanding these factors can help in defining the second line therapy towards a more streamlined management of diabetes.