Background Timely diagnosis can delay progression to poor clinical outcomes and biomarker endpoints in CKD. Our objective was to analyze how the implementation of the 2021 CKD-EPI Creatinine Equation (CKD-EPI 2021) affected time to the doubling of serum creatinine, prescription or dispense of potassium-lowering drugs, hyperkalemia, and creation of arteriovenous graft fistula for dialysis within one year of CKD diagnosis.

Methods We used retrospective EHR data to create two cohorts of adult patients based on date of diagnosis. We followed patients from their CKD diagnosis to the occurrence of each outcome, their last medical encounter, or 1-year post diagnosis, whichever occurred first. The first cohort was diagnosed in 2021 when the CKD-EPI 2009 Creatinine Equation (pre-update cohort) was recommended. The second cohort was diagnosed in 2022 when CKD-EPI 2021 (post-update cohort) was recommended. Multivariable models for the time relationship between cohort and each outcome were adjusted for demographics, social determinants of health, and comorbidities. As CKD-EPI 2021 was race-free, we also considered the interaction between cohort and race.

Results We found 261,774 patients with a first-time CKD diagnosis. After implementation of CKD-EPI 2021, patients were less likely to have a diagnosis of hyperkalemia, potassium-lowering drug prescription, a doubling of serum creatinine, or an arteriovenous graft fistula placement within a year of CKD diagnosis. Black patients in the post-update cohort were less likely to be diagnosed with hyperkalemia compared to Black patients in the pre-update cohort (AHR 0.83; CI 0.80, 0.86), but Black patients overall were significantly more likely than non-Black patients to have hyperkalemia.

Conclusions Time to poor clinical outcomes and biomarkers differs by the date of CKD diagnosis. Future work should elucidate the mechanisms driving these differences, whether there have been significant changes in treatment practices since the CKD-EPI 2021 recommendation, and long-term effects of each outcome.

All authors are employees of Truveta, Inc

This study did not receive any funding.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

Normalized electronic health record data are de-identified by expert determination under the HIPAA Privacy Rule before being made available to researchers. In accordance with 45 C.F.R. 46.101 Protection of Human Subjects, our study did not require Institutional Review Board approval because it used only deidentified medical records. All data used in this study are publicly available to Truveta subscribers and may be accessed at studio.truveta.com.

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

The data used in this study are available to all Truveta subscribers and may be accessed at studio.truveta.com.