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Cosmos Study

Chronic Kidney Disease Diagnosed Earlier, Especially in Black Patients

May 30, 2023
Dual-Team Study
Team A:Kersten Bartelt, RNAlex Piff 
Team B:Sam Butler, MDBrendan Joyce

Key Findings

  • Chronic kidney disease (CKD) was diagnosed earlier and at less severe stages in 2021 and 2022 compared to 2018 as evidenced by higher average initial eGFR at CKD diagnosis.  
  • The average eGFR at initial diagnosis in Black patients increased from 52.3 mL/min in 2018 to 55.2 mL/min in 2022. 

In July 2019, President Trump signed an executive order to improve kidney health by incentivizing preventative care, education strategies, payment models, and interventions.1 Additionally, in September 2021, a joint task force made up of members from the National Kidney Foundation and American Society of Nephrology (CKD-EPI) announced a race-free calculation of eGFR. Previously, calculations for eGFR often included a variable for race that resulted in higher eGFR values for Black patients. Higher eGFR values typically indicate that the kidneys are functioning well. Consequently, fewer Black patients were diagnosed with chronic kidney disease (CKD) or diagnosed with less severe cases of CKD as staging of CKD is largely dependent on eGFR values.2 Some organizations, however, implemented race-free eGFR calculations much earlier than 2021, some as early as 2017.3 

To better understand whether changes in eGFR calculations might be correlated with changes in CKD diagnosis, we studied 472,634 patients diagnosed with initial CKD of at least stage 2 from January 1, 2018, to December 31, 2022, to determine the average eGFR at initial diagnosis of CKD and whether that has changed over time.  

Using serum creatinine values, we calculated the race-free eGFR at time of initial diagnosis for each patient and determined the average eGFR at initial diagnosis for all patients by race or ethnicity per month. We found that the average eGFR at initial CKD diagnosis has risen from an average of 53.7 mL/min in January 2018 to 55.9 mL/min in December 2022.  This increase suggests that patients are likely being diagnosed earlier than in previous years. Increases in average eGFR at diagnosis are seen across all races and ethnicities.  

Figure 1
Average eGFR at CKD Diagnosis by Race and Ethnicity
Average eGFR at CKD Diagnosis by Race and Ethnicity
Figure 1. Three-month rolling average eGFR at initial diagnosis of CKD by month from January 2018 through December 2022 stratified by patient race and ethnicity. 

These findings suggest that initiatives from the executive order as well as the adoption of the race-free eGFR might be correlated with earlier diagnosis of CKD, helping to reduce the previous disparities seen between Black patients and other racial and ethnic groups in CKD diagnosis. 

These data come from Cosmos, a HIPAA-defined Limited Data Set of more than 185 million patients from 200 Epic organizations including 1,147 hospitals and over 25,000 clinics, serving patients in all 50 states and Lebanon. This study was completed by two teams that worked independently, each composed of a clinician and research scientists. The two teams came to similar conclusions. 

References

  1. Administration of Donald J. Trump, 2019. Executive Order 13879 – Advancing American Kidney Health. July 10, 2019. DCPD-201900464.pdf (govinfo.gov). Accessed on May 5, 2023. 
  2. Inker LA, Eneanya ND, Coresh J, et al. New Creatinine- and Cystatin C-Based Equations to Estimate GFR without Race. N Engl J Med. 2021;385(19):1737-1749. doi:10.1056/NEJMoa2102953 
  3. Zoler, ML. Dropping Race-Based eGFR Adjustment Gains Traction in US. Medscape. Dropping Race-Based eGFR Adjustment Gains Traction in US (medscape.com). Accessed on April 17, 2023.