{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T12:47:56Z","timestamp":1785934076026,"version":"3.56.0"},"reference-count":15,"publisher":"SAGE Publications","issue":"9","license":[{"start":{"date-parts":[[2025,12,29]],"date-time":"2025-12-29T00:00:00Z","timestamp":1766966400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["Ann Pharmacother"],"published-print":{"date-parts":[[2026,9]]},"abstract":"\n Background:<\/jats:title>\n Glomerular filtration rate (GFR) is commonly estimated with equations using creatinine, cystatin C, or a combination of both. Drug dosages may differ depending on the which equation.<\/jats:p>\n <\/jats:sec>\n \n Objectives:<\/jats:title>\n \n This study determined estimated GFRs from 4 common equations, their correlations, and the subsequent variations of predicted vancomycin half-life (t\n 1\/2<\/jats:sub>\n ).\n <\/jats:p>\n <\/jats:sec>\n \n Methods:<\/jats:title>\n \n Retrospective cohort study of critically ill adults with GFR estimations based on Cockcroft-Gault (CrCl\n CG<\/jats:sub>\n ), 2021 CKD-EPI Creatinine (eGFR\n cr<\/jats:sub>\n ), 2012 CKD-EPI Cystatin C (eGFR\n cys<\/jats:sub>\n ), and 2021 CKD-EPI Creatinine-Cystatin (eGFR\n cr-cys<\/jats:sub>\n ). Patients were excluded if pregnant, dialysis dependent prior to admission, or sampling occurred within 24 hours of renal replacement therapy. Statistical analyses used MANOVA and Pearson correlation coefficient (\n r<\/jats:italic>\n 2<\/jats:sup>\n ). Bayesian modeling population estimates predicted vancomycin t\n 1\/2<\/jats:sub>\n .\n <\/jats:p>\n <\/jats:sec>\n \n Results:<\/jats:title>\n \n Sixty-three patients with 104 GFR estimates were assessed. Mean age was 58.5 \u00b1 15.2 years. Mean creatinine and cystatin C were 1.78 \u00b1 2.1 mg\/dL and 2.28 \u00b1 1.2 mg\/L, respectively. Mean estimated GFRs were 76.6 \u00b1 59.2 mL\/min, 72 \u00b1 41.4 mL\/min, 38 \u00b1 27.5 mL\/min, and 47.3 \u00b1 32.7 mL\/min for CrCl\n CG<\/jats:sub>\n , eGFR\n cr<\/jats:sub>\n , eGFR\n cys<\/jats:sub>\n , and eGFR\n cr-cys<\/jats:sub>\n , respectively (\n P<\/jats:italic>\n < 0.0001).\n r<\/jats:italic>\n 2<\/jats:sup>\n (all\n P<\/jats:italic>\n < 0.0001) were 0.82 for CrCl\n CG<\/jats:sub>\n versus eGFR\n cr<\/jats:sub>\n , 0.54 for CrCl\n CG<\/jats:sub>\n versus eGFR\n cys<\/jats:sub>\n , 0.72 for CrCl\n CG<\/jats:sub>\n versus eGFR\n cr-cys<\/jats:sub>\n , 0.57 for eGFR\n cr<\/jats:sub>\n versus eGFR\n cys<\/jats:sub>\n , 0.77 for eGFR\n cr<\/jats:sub>\n versus eGFR\n cr-cys<\/jats:sub>\n , and 0.92 for eGFR\n cys<\/jats:sub>\n versus eGFR\n cr-cys<\/jats:sub>\n . Mean creatinine and cystatin C for vancomycin half-life estimations were 2.72 \u00b1 3.48 mg\/dL and 2.76 \u00b1 1.1 mg\/L, respectively. Mean predicted t\n 1\/2<\/jats:sub>\n values from 17 patients with vancomycin monitoring were 33.3 \u00b1 22.7 hours, 35.7 \u00b1 27.5 hours, 43.2 \u00b1 40.9 hours, and 38.7 \u00b1 37.3 hours, respectively (\n P<\/jats:italic>\n = 0.85).\n <\/jats:p>\n <\/jats:sec>\n \n Conclusions and Relevance:<\/jats:title>\n \n GFR estimations varied substantially with creatinine-based equations resulting in higher values. Correlation analyses revealed moderate to strong associations between equations. Discrepancies between GFR estimations were more apparent at higher GFRs. The variable GFR estimations led to substantial differences in predicted vancomycin t\n 1\/2<\/jats:sub>\n . Clinicians must be aware that dosing disparities may occur based on the GFR estimation used.\n <\/jats:p>\n <\/jats:sec>","DOI":"10.1177\/10600280251378502","type":"journal-article","created":{"date-parts":[[2025,12,29]],"date-time":"2025-12-29T10:21:22Z","timestamp":1767003682000},"page":"866-871","update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":1,"title":["Estimating GFR Using Creatinine, Cystatin C, or Both and the Impact on Predicted Vancomycin Half-Life"],"prefix":"10.1177","volume":"60","author":[{"given":"Amanda","family":"Dobson","sequence":"first","affiliation":[{"name":"Department of Pharmacy, UCHealth University of Colorado Hospital, Aurora, CO, USA"},{"name":"Medical University of South Carolina, Charleston, SC, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3569-5506","authenticated-orcid":false,"given":"Robert","family":"MacLaren","sequence":"additional","affiliation":[{"name":"Department of Clinical Pharmacy, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz, Aurora, CO, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shelby","family":"Pons","sequence":"additional","affiliation":[{"name":"Department of Pharmacy, UCHealth University of Colorado Hospital, Aurora, CO, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michelle","family":"Krey","sequence":"additional","affiliation":[{"name":"Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz, Aurora, CO, USA"},{"name":"Clinical Science and Specialty Ophthalmology and Neuroscience, Johnson & Johnson, New Brunswick, NJ, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","published-online":{"date-parts":[[2025,12,29]]},"reference":[{"key":"e_1_3_2_2_2","unstructured":"Glomerular Filtration Rate (GFR). National Kidney Foundation. Accessed July 7 2025. https:\/\/www.kidney.org\/glomerular-filtration-rate-gfr."},{"key":"e_1_3_2_3_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.mayocp.2018.08.002"},{"key":"e_1_3_2_4_2","doi-asserted-by":"publisher","DOI":"10.1097\/CCM.0000000000004650"},{"key":"e_1_3_2_5_2","doi-asserted-by":"publisher","DOI":"10.7326\/0003-4819-150-9-200905050-00006"},{"key":"e_1_3_2_6_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa1114248"},{"key":"e_1_3_2_7_2","doi-asserted-by":"publisher","DOI":"10.1111\/aas.14173"},{"key":"e_1_3_2_8_2","doi-asserted-by":"publisher","DOI":"10.1136\/ejhpharm-2023-003738"},{"key":"e_1_3_2_9_2","doi-asserted-by":"publisher","DOI":"10.1111\/aas.14540"},{"key":"e_1_3_2_10_2","doi-asserted-by":"publisher","DOI":"10.1002\/phar.70000"},{"key":"e_1_3_2_11_2","doi-asserted-by":"publisher","DOI":"10.1002\/phar.2175"},{"key":"e_1_3_2_12_2","doi-asserted-by":"publisher","DOI":"10.1097\/CCM.0000000000006622"},{"key":"e_1_3_2_13_2","doi-asserted-by":"publisher","DOI":"10.1097\/CCE.0000000000001011"},{"key":"e_1_3_2_14_2","doi-asserted-by":"publisher","DOI":"10.1053\/j.ajkd.2016.11.016"},{"key":"e_1_3_2_15_2","doi-asserted-by":"publisher","DOI":"10.7326\/0003-4819-147-8-200710160-00010"},{"key":"e_1_3_2_16_2","unstructured":"Vancomycin calculator pharmacokinetic calculator with Bayesian modeling. Accessed June 7 2024. https:\/\/clincalc.com\/vancomycin."}],"container-title":["Annals of Pharmacotherapy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/10600280251378502","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/full-xml\/10.1177\/10600280251378502","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/10600280251378502","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T12:07:35Z","timestamp":1785931655000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1177\/10600280251378502"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,12,29]]},"references-count":15,"journal-issue":{"issue":"9","published-print":{"date-parts":[[2026,9]]}},"alternative-id":["10.1177\/10600280251378502"],"URL":"https:\/\/doi.org\/10.1177\/10600280251378502","relation":{},"ISSN":["1060-0280","1542-6270"],"issn-type":[{"value":"1060-0280","type":"print"},{"value":"1542-6270","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,12,29]]}}}