Abstract: SA-PO0928
National Trends in the Uptake of Cystatin C-Based and Composite Cystatin C/Creatinine-Based eGFR Estimation
Session Information
- Pathology: Updates and Insights
November 08, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Pathology and Lab Medicine
- 1800 Pathology and Lab Medicine
Authors
- Bisen, Shivani, NYU Langone Health, New York, New York, United States
- Terlizzi, Kelly, NYU Langone Health, New York, New York, United States
- Jaffe, Ian S, NYU Langone Health, New York, New York, United States
- Husain, Syed Ali, Columbia University Vagelos College of Physicians and Surgeons, New York, New York, United States
- Mankowski, Michal, NYU Langone Health, New York, New York, United States
- Orandi, Babak, NYU Langone Health, New York, New York, United States
- Lonze, Bonnie E., NYU Langone Health, New York, New York, United States
- Coresh, Josef, NYU Langone Health, New York, New York, United States
- Grams, Morgan, NYU Langone Health, New York, New York, United States
- Segev, Dorry L., NYU Langone Health, New York, New York, United States
- Massie, Allan, NYU Langone Health, New York, New York, United States
Background
Current guidelines emphasize the role of cystatin C (cysC) measurements in addition to serum creatinine (SCr) in estimating GFR (eGFR). We characterize trends in the use of cysC testing in US clinical practice.
Methods
Using Epic Cosmos, a national EHR database, we identified all orders for SCr and cysC for 83 million patients with ≥1 of either, 2016-2024. We examined temporal trends in the proportion of patients with measured cysC. We performed logistic regression on a random 1% sample (starting 1/2021) to assess factors associated with cysC testing.
Results
242,236 patients (0.29%) had ≥1 cysC result. CysC use increased from <0.08% of patients pre-2021 to 0.26% in late 2024 (Figure). CysC was more likely to be measured in Black patients (OR 1.46; p<0.001) and those prescribed metformin or SGLT-2 inhibitors (OR 1.49; p<0.001) (Table). Patients with diagnosed CKD Stage ≥3 had 9x higher odds of undergoing cysC measurement; however, even among this group, only 1.41% of patients past 2021 had at least one measured cysC. Hypertension and heart failure were associated with increased cysC use (OR 1.45 and 1.21; both p<0.001).
Conclusion
Despite consensus recommendations from national organizations encouraging the incorporation of cysC into eGFR assessments for select patients, cysC remains underutilized in clinical practice, even for patients with CKD Stage ≥3.