The prevalence of CKD stages 3-5 by eGFR (%) in VA patients 10%-15%, with some variation by year of data. The prevalence of CKD increased with increasing age, from less than 1% in the youngest group (20-29 years) to greater than 20% in the oldest group (70+ years).
Chart Explanation: The prevalence of CKD stages 3-5 increased with increasing age for every race/ethnicity studied. For age groups under 60, they was no difference between racial/ethnic groups, while Asians and Hispanics in their 60s had slightly lower prevalence (7% v. 9-10% in 2011). In the age 70 and older group in 2011, Asians and Hispanics had a prevalence of CKD stages 3-5 of 13%, compared to 20% for non-Hispanic blacks and Native Americans/Native Alaskans, and 22% for non-Hispanic whites and Native Hawaiians/Pacific Islanders.
The Veteran’s Affairs (VA) data presented are from a national sample of health care visits to the VA Health System by eligible United States. 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 US 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 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 four-variable MDRD study formula, excluding dialysis and transplant patients. Estimated GFR (kidney function) was classified into five CKD categories (GFR ≥90, GFR 60 to 89, stage 3=GFR 30 to 59, stage 4=GFR 15 to 29, and stage 5= GFR<15 ml/min/1.73 m²) and “eGFR Unmeasured” for those patients who did not have serum creatinine testing. Inpatient serum creatinine data were not examined as they would be influenced by 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), outpatient diagnosis codes (ICD-9-CM: V56, V451 and E8791) and inpatient and outpatient diagnosis codes (ICD-9-CM: 5856) to indicate dialysis. Kidney transplant patients were identified by inpatient and outpatient ICD-9-CM diagnosis code V420 and inpatient procedure code 5569.
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.
|Description of Measure||Prevalence of stages 3-5 CKD, excluding ESRD patients, by eGFR (kidney function)|
|Type of Data Source||Administrative Data|
|Data Set||VA National 5% Sample (FY05-FY09) and 100% (FY10-present)|
|Health Care System Data||Yes|
|Regional or National?||National|
|Demographic Group||Patients in VA system|
|Numerator||Patients in denominator with creatinine testing meeting criteria for CKD stages 3-5, not including 5D and 5T|
|Denominator||Patients aged >20 who have at least one outpatient visit OR have at least one outpatient serum creatinine measurement within the specified age-race group|
|Definition of CKD||Stages 3-5 (eGFR < 60 ml/min/1.73 m²) excluding dialysis and transplant |
|Glomerular filtration rate||Estimated using the four-variable MDRD study equation: eGFR=186 × [(serum creatinine in mg/dl)**1.154] × age**-0.203 × (0.742 if female) × (1.210 if African-American). Missing race/ethnicity was coded as white. ** signifies "raised to the power of".|
|Primary Data Source Indicator||Serum Creatinine Lab Result Value|
|Primary Indicator Method of Measurement||Laboratory: A valid serum creatinine value was defined as 0.3-15.0 mg/dl. Any values outside of this range were set to “missing.” No more than 1% of serum creatinine values in each cohort were outside of this range.|
|Secondary (1) Variable||Age = (Date of Visit - Date of Birth)/365.25|
|Secondary (1) Indicator Method of Measurement||Outpatient Visit|
|Secondary (2) Variable||Race/Ethnicity|
|Secondary (2) Indicator Method of Measurement||Outpatient and/or inpatient visit|
|Frequency of Measurement (Primary)||Multiple measurements per patient|
|Period Currently Available||2005–2012|
|Limitations of Indicator||Use of methods to standardize creatinine varies by facility.
Occurrence of CKD Stages 1 and 2 can not be calculated due to the low rate of urine albumin testing.|