The current definition of chronic kidney disease (CKD) based on estimated glomerular filtration rate (eGFR) has led to one in eight people being labeled as having the condition, compared to the actual yearly treatment rate of one person for every 3,000 to 5,000 for end-stage renal disease (ESRD), a study found.
The result is overdiagnosis and overtreatment of people unlikely to ever progress to ESRD, reviewers said in an analysis published online July 30 in BMJ.
A 2002 guideline defined CKD by eGFR based on serum creatinine or cystatin C levels and an assessment of kidney damage most commonly derived from albuminuria. The reviewers noted that, by these criteria, anyone with an eGFR below 60 mL/min/1.73 m2 for three months or longer could be diagnosed as having CKD of stage 3A or greater, even if they have no other signs of kidney disease.
The goal had been to capture patients who progressed all the way to ESRD unchecked, especially in the African-American community, the authors wrote. This definition has resulted in almost 14% of U.S. adults being labeled as having CKD. A third of the people who meet the definition of CKD also meet the definition of stage 3A. Most are older than 65, and many have an eGFR that falls within the 5th to 95th percentile for their age. About 75% have no urine markers of kidney damage, such as albuminuria.
Reviewers suggested several ways for clinicians to improve CKD management:
- Share uncertainty about diagnostic thresholds and measurements with patients.
- Look for potential evidence of anemia, abnormal urinalysis results or abnormalities on renal ultrasonography.
- Be aware of the variability of results when testing eGFR and albuminuria and of the need to repeat the tests, soon after the first test and again after three months.
- Avoid the label of CKD for people age 65 years and older with eGFR stage 3A without albuminuria.
- Recognize that older people with stable but modestly reduced eGFR of 45 to 59 mL/min/1.73 m2 are unlikely to have a high risk unless they have persistent overt albuminuria.