Type 2 diabetes mellitus and renal impairment in a large outpatient electronic medical records database: rates of diagnosis and antihyperglycemic medication dose adjustment.

OBJECTIVE

To assess rates of diagnosis and antihyperglycemic dose adjustment in patients with moderate to end-stage renal impairment (RI) and type 2 diabetes mellitus (T2DM).

METHODS

Retrospective database analysis using GE Centricity Outpatient Electronic Medical Records. Patients aged ≥ 18 years with evidence of T2DM (International Classification of Diseases, Ninth Edition, Clinical Modification codes 250.x0 and 250.x2) between January 1, 2000 and June 30, 2009, and ≥ 12 months of data after identification were selected. Moderate to end-stage RI was evaluated using a formula-derived estimated glomerular filtration rate (eGFR) based on serum creatinine (SCr). Patients were classified as moderate (eGFR, 30-59 mL/min/1.73 m(2)), severe (eGFR, 15-29 mL/min/1.73 m(2)), or end-stage (eGFR, < 15 mL/min/1.73 m(2)), per the National Kidney Foundation guidelines, based on the first-observed SCr test. Among patients with a physician diagnosis, the time to diagnosis was reported. Dose adjustment was reported for patients receiving metformin and sitagliptin. Predictors of progression to end-stage RI based on logistic regressions were examined.

RESULTS

35.2% of patients with T2DM had evidence of moderate to end-stage RI. Of these patients, 20% had a chart-documented physician diagnosis (range, 16% [moderate RI] to 66% [end-stage RI]). Patients with moderate or severe RI had a physician diagnosis mean of 253.4 (standard deviation [SD], 584.5) and 86.9 (SD, 417.4) days, respectively, after the eGFR calculation indicating RI. Patients with end-stage RI had a physician diagnosis mean of 83.6 (SD, 399.2) days before the eGFR calculation. After the eGFR calculation, 15.1% and 0.1% of patients with orders for sitagliptin and metformin, respectively, received doses of the drug appropriate for their degree of RI. Among patients with moderate or severe RI, appropriate diagnosis of RI was associated with significantly lower odds of progressing to end-stage RI (odds ratio, 0.200; 95% confidence interval, 0.188-0.213).

CONCLUSIONS

Renal impairment is common but often undetected in patients with T2DM. Patients with a documented RI diagnosis have lower odds of progression to end-stage RI. Metformin and sitagliptin are frequently used at inappropriate doses in patients with RI. Further analyses to understand the clinical and economic consequences of these findings are needed.