Study Suggests Low Rate of Referral for Outpatient Nephrology Consultation for Veterans Hospitalized with Acute Kidney Injury

BACKGROUND:
Despite improving sophistication in the provision of hospital care, acute kidney injury (AKI) is increasingly common and remains closely associated with increases in short-term mortality and healthcare use. Moreover, recent observational studies have linked the progression of chronic kidney disease (CKD), including end-stage renal disease, to previous AKI among patients who survive to hospital discharge. One quality of care indicator for patients with persistent chronic kidney disease after an episode of AKI is the rate of nephrology referral. Data from the CKD literature suggest that early nephrology referral can reduce morbidity and mortality in patients with advanced kidney disease. This study examined the likelihood of nephrology referral among survivors of AKI at risk for subsequent decline in kidney function. Nephrology referral was defined as an order for outpatient nephrology consultation in any clinical setting. Using VA data, investigators identified 3,929 Veterans who had a hospitalization complicated by AKI between 1/03 and 12/08, with impaired kidney function at least 30 days after peak injury. Veterans were followed for 12 months to assess improvement in kidney function, referral for nephrology care, dialysis initiation, and mortality (30-395 days after peak injury). Demographics and comorbid conditions also were assessed.

FINDINGS:

• The majority of Veterans (56%) had persistent CKD (Stage III or IV) one year following their acute event. Consistent with non-VA cohorts, there was a low rate of outpatient referral for kidney specialist care among Veterans hospitalized with acute kidney injury. The cumulative incidence of nephrology referral before death, dialysis, or improvement in kidney function was 8.5%.
• Veterans who were not referred for specialty care tended to be slightly older, were less likely to have a diagnosis of congestive heart failure, and had modestly higher kidney function at baseline. There were no statistically significant differences in race, sex, or rates of coronary artery disease, hypertension, peripheral vascular disease, or severity of AKI.
• Overall mortality during the 12-month surveillance period was 22%.

LIMITATIONS:

• Data used in this study were from 2003 to 2008, and did not include more recent data that might reflect improved outpatient referrals for Veterans with AKI.
• Despite incorporating “fee-basis” billing data for outpatient referrals, it is likely that some patients obtaining nephrology care at a non-VA facility were not captured.

NOTE:
Investigators are currently analyzing data to evaluate whether CKD surveillance is being conducted in the primary care clinic, which could partially address the receipt of appropriate care. If receipt-of-care measures are low, they hope to design a web-based clinical decision support system for point-of-care and patient panel support to encourage better attention to measures to track and slow CKD progression.

AUTHOR/FUNDING INFORMATION:
Dr. Matheny is supported by an HSR&D Career Development Award. Drs. Peterson, Hung, Speroff, and Matheny are part of the VA Tennessee Valley Geriatric Research Education and Clinical Center.

Siew E, Peterson J, Eden S, Hung A, Speroff T, Ikizler T, and Matheny M. Outpatient Nephrology Referral Rates after Acute Kidney Injury. Journal of the American Society of Nephrology December 8, 2011;e-pub ahead of print.