CKD progression and mortality among older patients with diabetes.

BACKGROUND: Chronic kidney disease (CKD) is clearly associated with an increased risk for adverse outcomes; however, the cumulative impact of renal and cardiac complications in high-risk populations is not known. In addition, little is known about patterns of nephrology care in patients with CKD.
METHODS: We conducted a retrospective longitudinal cohort study assessing CKD prevalence and progression, associations with all-cause mortality, and variations in patterns of nephrology consultation in older patients with diabetes in a vertically integrated health care system.
RESULTS: A total of 12,570 patients within a 7-Veterans Affairs hospital service network in 1998 to 1999 were identified by means of computerized records. Nearly half (48%) were affected with CKD; most had mild to moderate CKD. After an observation period of 3 years, mortality rates in those unaffected with CKD were high (4.7 deaths/100 person-years) and increased substantially with progressive CKD (eg, 20.1 deaths/100 person-years with an estimated glomerular filtration rate [GFR] of 15 to 29 mL/min/1.73 m2 [0.25 to 0.48 mL/s/1.73 m2]). Only 7.2% of patients with CKD had a nephrology visit during the entire 5-year study period. Although visits increased with more advanced CKD, only 32% of patients with an estimated GFR of 15 to 29 mL/min/1.73 m2 had been seen in a nephrology clinic. We also found that nephrology referrals were driven preferentially by elevations in serum creatinine levels, rather than low GFRs.
CONCLUSION: Many in this cohort of older patients with diabetes are affected with CKD. Mortality rates are high, and mortality risks associated with CKD amplify those of other risk factors. Nephrology visits are low and may represent an unexploited resource for improving CKD management. Underrecognition of CKD likely is related to overestimation of kidney function by relying on serum creatinine level in elderly patients.