Overdiagnosis of CKD in older adults
The current diagnostic criteria of CKD, which is based on an estimated glomerular filtration rate (eGFR) of less than 60, has been up for debate, as glomerular filtration rate (GFR) physiologically decreases with age. Fixed thresholds can lead to underdiagnosis of CKD in younger adults and overdiagnosis of CKD in older adults. Age-adapted thresholds for the diagnosis of CKD have been proposed, with the suggestion of an eGFR threshold of 45mL/min/1.73 m2 for adults aged 65 and older.7
The clinical implication of using an age-adapted eGFR threshold definition was investigated in a 2021 cohort study by Liu et al.8 In this study, outcomes of adults diagnosed with CKD using a fixed threshold versus age-adapted threshold were compared with a healthy cohort.
A fixed threshold led to a 60% higher incidence of CKD diagnosis. However, incidence of renal failure and all-cause mortality in older adults with an eGFR between 45-59 /min/1.73 m2 with normal or mild albuminuria was of similar magnitude to the healthy cohort at 5 years of follow-up.
These findings support the use of age-adapted thresholds for the diagnosis of CKD in older adults, as an earlier diagnosis of mild CKD does not equate to clinical benefits, but could lead to harms of unnecessary interventions and patient anxiety.
Dr. Mengru “Ruru” Wang is a geriatrician and internist at the University of Washington, Seattle. She practices full-spectrum medicine, seeing patients in primary care, nursing homes, and acute care. Dr. Wang has no disclosures related to this piece.
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