The Veteran’s Affairs (VA) data presented are from a national sample of health care visits to the VA Health System by eligible U. S. veterans. During any given year, roughly 70% of the outpatient population receives at least one serum creatinine test. While the demographics of VA Health System users are distinct from the general U.S. population, the VA data allow a snapshot of clinical practices across the nation.

National VA data were examined. Within each VISN (Veterans Integrated Service Network), a 5% random sample of patients was extracted from the national VA data repository each fiscal year (FY) from FY2005 to FY2009. Starting in FY2010 and continuing in future years, analyses were performed on the entire patient population (100% sample).

To examine acute kidney injury (AKI) in the hospital setting within the VA, we determined an index hospitalization for each fiscal year. This was the patient's first hospitalization of the year that had a length of stay of 2 days or more with 2 or more inpatient serum creatinine test results. A baseline serum creatinine measurement was determined from outpatient serum creatinine test results at least 7 days prior to the index hospitalization. Patients with evidence of pre-admission end-stage renal disease or a baseline MDRD estimated GFR less than 15 were excluded. An episode of AKI during the index hospitalization was defined by an increase in serum creatinine from baseline of 0.3mg/dL that did not decrease within 48 hours.

All outpatient lab results between discharge and 6 months post discharge for patients alive 6 months after discharge were examined to see if a microalbuminuria or urine albumin creatinine ratio test was performed.

This material is the result of work supported with resources and the use of facilities at the Veterans Affairs Ann Arbor Healthcare System, Ann Arbor, Michigan.