Chronic kidney disease (CKD) is a progressive condition characterized by declining kidney function. It is often undetected until later stages when dialysis or kidney failure becomes imminent.1 An estimated 35.5 million U.S. adults have CKD, yet many remain undiagnosed, partly due to asymptomatic early stages and inconsistent screening practices.1 Identifying CKD early can mitigate the risk of cardiovascular disease, acute kidney injury, and progression to kidney failure.2 Despite these benefits, missed and discordant CKD diagnoses remain common.1 CKD staging for stages 3a and greater are based on the patient’s estimated glomerular filtration rate (eGFR), with lower values indicating higher stages of CKD.3
We examined how often patients whose eGFR levels indicate they have stage 3 or higher CKD do not have a documented CKD diagnosis. We studied 681,583 patients with multiple creatinine labs at least 90 days apart whose calculated eGFR classified them as stage 3 or higher. Patients diagnosed with end-stage renal disease (ESRD) or those with a kidney transplant were excluded from this study, as transplant or dialysis procedures can interfere with eGFR values.
We found that, while most patients had a CKD diagnosis documented when their eGFR results reflect CKD, females were nearly twice as likely to be undiagnosed as males, as seen in Figure 1. The highest undiagnosed rate was among women without diabetes (20.0%).
Next, we evaluated how often the stage of the CKD diagnosis differed from the stage indicated by a patient’s eGFR results. We found that most patients have a diagnosed stage that matches their calculated stage, as seen in Figure 2. Patients classified as stage 5 were the least likely to have a staged diagnosis that matched their calculated stage. However, there were comparatively few patients with an eGFR indicating stage 5, and the exclusion of patients diagnosed with ESRD or who have had a transplant may disproportionately affect the rates observed among the stage 5 population.
