Quantifying Time to Diagnosis of CKD in the United States

BACKGROUND: An estimated 14% of US adults have CKD with over 90% unaware of their condition. Healthcare professionals diagnose CKD after two abnormal laboratory test results taken at least three months apart. While there is evidence that delays from CKD onset to documentation are common, these delays remain unquantified. The study objective was to quantify the time from laboratory-based evidence of CKD to the documentation of CKD using ICD codes. METHODS: A retrospective longitudinal cohort study was conducted using 2009 -2020 Optum® Market Clarity data. Adults aged 18 years and older were followed from the date of the second of two estimated glomerular filtration rates (eGFR) < 60 mL/min/1.73 m 2 , three to 12 months apart until the first ICD 9/10 diagnosis of CKD, or censoring. Survival analysis was used to compare time to documentation among Kidney Disease: Improving Global Outcomes (KDIGO) categories considering while analyzing deaths as competing risks. RESULTS: A total of 1.39 million adults with laboratory evidence of CKD and a mean age of 71 years (standard deviation (SD) 10; 63% women; 87% Caucasian) were included. Over 94% were in KDIGO stage G3, 5% in stage G4, and 1% in stage G5. The median time to CKD documentation was 3.6 years (interquartile range [IQR]: 1.0 – 8.4), ranging from 4.8 years for those in KDIGO G3a, 2 years in KDIGO G3b, and less than 1 year in KDIGO G4 and G5. Patient characteristics associated with longer time to CKD diagnosis included: absence of diabetes or HF; less severe CKD; older age; and female sex. CONCLUSIONS: There was a substantial delay between laboratory evidence of CKD and the diagnosis being documented via coding. Reducing this delay offers a target for earlier recognition and management of CKD.