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, ~ 70% of the outpatient population receives a 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 for veterans with at least one outpatient visit during the federal fiscal year. To estimate prevalence of CKD, outpatient serum creatinine laboratory results (averaged if a patient had more than one test during the fiscal year) were used to calculate an estimated glomerular filtration rate (eGFR) for each patient using the CKD-EPI equation, excluding dialysis and transplant patients. Estimated GFR (kidney function) was classified into five CKD categories (eGFR =90, eGFR 60-89, stage 3=eGFR 30-59, stage 4=eGFR 15 to 29, and stage 5 without dialysis=eGFR<15 ml/min/1.73 m² and “eGFR Unmeasured” for those patients without serum creatinine testing. Inpatient serum creatinine data were not used as they would be affected by the presence of acute illnesses. Due to the infrequency of testing, albuminuria was not included in the definition of CKD. Dialysis patients were defined by clinic stop-codes (602-611), outpatient procedure codes for dialysis (CPT4: 90921 and 90925), diagnosis codes (ICD-9-CM: 585.6, V56, V45.1 and E87.91 and ICD-10-CM: N18.6, Y84.1, Z49.31, Z49.01, Z49.02, Z49.31, Z49.32 and Z49.33) to indicate dialysis. Kidney transplant patients were identified by inpatient and outpatient ICD-9-CM diagnosis code V420 and 996.81, ICD-10-CM diagnosis codes T86.X, Z48.22 and Z9.40, and inpatient procedure and surgery codes 55.69. Dialysis and transplant patients are not included in stage 5.
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.