Fixed vs. Age-Adapted Glomerular Filtration Rate Thresholds for Diagnosing Chronic Kidney Disease

An estimated glomerular filtration rate (eGFR) of <60 mL/minute/1.73 m² is accepted widely as indicating substantial (i.e., stage 3) chronic kidney disease (CKD). However, this fixed threshold might be associated with overdiagnosing CKD in older people because of age-related physiological loss of GFR. In this population-based study from Alberta, researchers compared outcomes of adults with incident CKD using two definitions: a fixed eGFR threshold of <60 mL/minute/1.73 m² and age-adapted eGFR thresholds of 75, 60, and 45 mL/minute/1.73 m² for ages <40, 40 to 64, and ≥65, respectively.

The main findings were:

• Overall, the incidence rate for CKD was much higher with the fixed threshold than with the age-adapted thresholds; the difference was pa…