{"doi":"10.1681/asn.2020081171","title":"Authors’ Reply","abstract":"To address the question raised by Dr. Rutkowski,1 we performed a post hoc analysis examining how often Black patients with an eGFR of 30–44 ml/min per 1.73 m2, calculated using the CKD–Epidemiology Collaboration (CKD-EPI) equation, who were prescribed metformin, would have been reclassified as having an eGFR <30 ml/min per 1.73 m2 if GFR were estimated using the CKD-EPI equation without the race coefficient. This reclassification is clinically important because metformin is contraindicated for patients with eGFR <30 ml/min per 1.73 m2, according to the current Food and Drug Administration (FDA) label.2 In the primary cohort (Johns Hopkins Medicine) of our study,3 121 Black patients with a CKD-EPI eGFR of 30–44 ml/min per 1.73 m2 were prescribed metformin after the FDA label change. Of these patients, 15 (12.4%) would have an eGFR <30 ml/min per 1.73 m2 if the race coefficient were not used. In the replication cohorts (OptumLabs Data Warehouse), 1850 Black patients with a CKD-EPI eGFR of 30–44 ml/min per 1.73 m2 were prescribed metformin in the third year after the FDA label change, and 288 (15.6%) would have an eGFR <30 ml/min per 1.73 m2 if the race coefficient were not used. The patients who were reclassified from eGFR of 30–44 ml/min per 1.73 m2 (metformin eligible) to eGFR <30 ml/min per 1.73 m2 (metformin ineligible) had a range of eGFR from 30.1 to 34.8 ml/min per 1.73 m2 when GFR was estimated using the CKD-EPI equation with the race coefficient. These findings suggest that approximately 12%–16% of patients eligible for metformin with CKD-EPI eGFR of 30–44 ml/min per 1.73 m2 would be ineligible for metformin prescription if GFR were estimated using the CKD-EPI equation without the race coefficient. Disclosures M. Grams reports Honoraria: Academic institutions for giving grand rounds and ASN for Young Investigator Award; Scientific Advisor or Membership: AJKD; CJASN; JASN Editorial Fellowship Committee; NKF Scientific Advisory Board; KDIGO Executive Committee, USRDS Scientific; Advisory Board Other Interests/Relationships: NKF, which receives funding from Relypsa, Abbvie, Thrasos; Received travel support from DCI to speak at the annual meeting and KDIGO for participation in scientific meetings and the executive committee. J. Shin reports grants from Merck, outside the submitted work. All remaining authors have nothing to disclose. Funding J. Shin reports National Institutes of Health grants, during the conduct of the study.","journal":"Journal of the American Society of Nephrology","year":2020,"id":133991,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9492,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2020-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":73223,"name":"Yingying Sang","orcid":null,"position":1,"is_corresponding":false},{"id":589796,"name":"Stephan Dunning","orcid":"0000-0003-3109-0136","position":2,"is_corresponding":false},{"id":73169,"name":"Morgan E. Grams","orcid":"0000-0002-4430-6023","position":3,"is_corresponding":false},{"id":484667,"name":"Jung‐Im Shin","orcid":"0000-0003-0374-6927","position":0,"is_corresponding":true}],"reference_count":2,"raw_metadata":null,"created_at":"2026-07-18T23:16:20.998822Z","pmid":"32931448","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}