San Diego, CA—Patients with type 2 diabetes and chronic kidney disease (CKD) are not being appropriately treated for their diabetes, according to a study based on a large electronic database from an integrated health system, presented at the 2011 Scientific Sessions of the American Diabetes Association.
In the study, 45% of patients were given oral antidiabetic drugs (OADs) that were not concordant with National Kidney Foundation (NKF) guidelines. Patients whose treatment was concordant with NKF guidelines had improved clinical outcomes, including superior glycemic control, lower risk for hypoglycemic episodes, and lower likelihood of hospitalization, the researchers stated. In addition, patients whose OAD treatment was concordant with NKF guidelines also had lower costs per encounter, lower diabetes-related costs, and lower hypoglycemia-related costs than those whose treatment was not NKF-guideline concordant.
“The findings suggest better clinical and economic outcomes associated with NKF-guideline concordant OAD treatment among patients with chronic kidney disease. Future research is needed to confirm these data,” said Shih-Yih Chen, PhD, United Biosource Corporation, Lexington, MA, and colleagues.
The study sample was culled from 46,204 patients with type 2 diabetes who used OADs from January 1, 2005, to October 31, 2010. The population was winnowed down to 6983 patients who met entry criteria (CKD stages 3-5, OAD within 3 months of index date). Of them, 55% (n = 3361) were receiving NKF-guideline concordant OAD treatment, and 45% (n = 2697) were not. The mean age was about 70 years; 37.6% of the guideline-concordant patients were male, and 48.3% of those not treated according to the guidelines were male. About 98% were Caucasian. About 90% had stage 3 CKD, about 7% had stage 4 disease, and about 3% had stage 5 disease.
Glycemic control (ie, hemoglobin A1c <7%) was achieved in 46.1% of guideline-concordant patients versus 36.1% of discordant patients; 23.9% and 27.9%, respectively, were hospitalized during 12-month follow-up.
Overall costs for inpatient and outpatient encounters were $6694 per patient in the concordant group versus $8142 for the discordant group; overall hypoglycemia-related encounter costs were $239 versus $525 per patient, respectively. Multivariate analysis (adjusted for age, insulin use during 12-month follow-up, gender, race, Charlson comorbidity index score, and CKD stage) showed that the adjusted marginal effect of not being treated according to NKF guidelines was $839 per patient for total encounter costs.
The authors cautioned that these results do not reflect concordance with guidelines other than those issued by the NKF. Also, it is not clear whether patients actually took OADs as prescribed. Medication costs were not assessed in this study. In addition, the findings reflect a single integrated health system and may not be generalizable to other settings.