Clinical and economic outcomes associated with National Kidney Foundation guideline-concordant oral antidiabetic drug treatment among type 2 diabetes patients with chronic kidney disease

Objective: To assess outcomes associated with oral anti-diabetic drug (OAD) treatment concordant with guidelines from the National Kidney Foundation (NKF) among type 2 diabetes mellitus (T2DM) patients with chronic kidney disease (CKD). Methods: Electronic health record data between 1/1/2005 and 10/31/2010 provided by an integrated health system were analyzed. T2DM patients were selected based on diagnosis from the health record. Patients with stages 3-5 CKD based on diagnosis or lab results were further identified with the date of first indicated CKD set as index date. Patients who had a medication order of OADs within three months of the index date were included. Patients were considered non-guideline-concordant if prescribed OADs that were recommended to be avoided or if they required dosage adjustment, but were unadjusted. Glycemic control, hospital admissions, and costs of encounters were assessed over a 12-month post-index period, and hypoglycemic events were evaluated until loss of follow-up. Regression analyses were performed, adjusting for patient demographic and clinical characteristics. Results: Among 6058 patients (mean age: 70; 42% male), 45% were guideline-concordant. After adjusting for patient characteristics, guideline-concordant patients had a lower risk for hypoglycemic events (HR: 0.72; 95% CI: 0.62-0.83), were less likely to have a hospital admission (OR: 0.87; 95% CI: 0.77-0.98), and more likely to have glycemic control (OR: 1.64, 95% CI: 1.46-1.84). Non-guideline-concordant patients had annual encounter costs of 1.10 times those of guideline-concordant patients (marginal cost = $731; P=0.04). Limitations: Unobservable confounders may still exist and bias the results; therefore, findings should be interpreted as associations instead of causations. Findings were based on a single integrated health system and may not be generalizable to larger populations. Conclusion: The findings of this exploratory study suggest that guideline-concordant treatment may yield better clinical and economic outcomes. Future research with a better controlled design is warranted to confirm these preliminary findings.