{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,7]],"date-time":"2026-01-07T07:33:03Z","timestamp":1767771183890,"version":"3.40.4"},"reference-count":0,"publisher":"S. Karger AG","issue":"5","license":[{"start":{"date-parts":[[2019,1,1]],"date-time":"2019-01-01T00:00:00Z","timestamp":1546300800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.karger.com\/Services\/SiteLicenses"},{"start":{"date-parts":[[2019,1,1]],"date-time":"2019-01-01T00:00:00Z","timestamp":1546300800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/www.karger.com\/Services\/SiteLicenses"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Am J Nephrol"],"published-print":{"date-parts":[[2019]]},"abstract":"<jats:p>&lt;b&gt;&lt;i&gt;Background:&lt;\/i&gt;&lt;\/b&gt; Within-patient tacrolimus level variability &amp;#x3e;30% has been shown to be a risk factor for de novo donor-specific antibody formation and death-censored graft failure among kidney transplant recipients. The burden of tacrolimus variability and the correlation between variability and subtherapeutic tacrolimus levels were examined in a large national data set. &lt;b&gt;&lt;i&gt;Methods:&lt;\/i&gt;&lt;\/b&gt; All tacrolimus levels drawn at LabCorp\u00ae facilities in the United States with a diagnosis code for kidney transplant between November 2011 and September 2017 were examined, excluding values that could represent new allografts. Tacrolimus variability was calculated if at least 3 levels were available. The percentage of subtherapeutic (&amp;#x3c;4.0 ng\/dL) tacrolimus levels (%subT) was also calculated. Interdependence between %subT and tacrolimus variability was assessed with correlation analysis and linear regression. &lt;b&gt;&lt;i&gt;Results:&lt;\/i&gt;&lt;\/b&gt; There were 410,257 tacrolimus levels among 27,375 patients, who had 11 (interquartile range [IQR] 6\u201320) tacrolimus levels over a median follow-up of 26.5 (IQR 12.8\u201346.1) months. Median tacrolimus variability was 30.6%, and 51.6% of patients exceeded 30% variability. Median %subT was 11.1% (IQR 0\u201330.8%), and 34.3% of patients had no subtherapeutic levels. The correlation coefficient between tacrolimus variability and %subT was 0.253 (&lt;i&gt;p&lt;\/i&gt;&amp;#x3c; 0.001). In linear regression, tacrolimus variability increased 1.86% for each 10% increase in %subT (&lt;i&gt;p&lt;\/i&gt; &amp;#x3c; 0.001), but R-squared for this model was only 0.06. &lt;b&gt;&lt;i&gt;Conclusion:&lt;\/i&gt;&lt;\/b&gt; More than half of established kidney transplant patients from a large national sample exhibited levels of tacrolimus variability that have been associated with inferior transplant outcomes. Tacrolimus variability has a weak association with subtherapeutic levels, but represents a more complicated constellation of clinical factors.<\/jats:p>","DOI":"10.1159\/000503167","type":"journal-article","created":{"date-parts":[[2019,9,25]],"date-time":"2019-09-25T21:00:56Z","timestamp":1569445256000},"page":"370-374","source":"Crossref","is-referenced-by-count":10,"title":["The Epidemiologic Burden of Tacrolimus Variability among Kidney Transplant Recipients in the United States"],"prefix":"10.1159","volume":"50","author":[{"given":"Pratik\u00a0B.","family":"Shah","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jennifer\u00a0L.","family":"Ennis","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Patrick\u00a0N.","family":"Cunningham","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Michelle\u00a0A.","family":"Josephson","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rita\u00a0L.","family":"McGill","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"127","published-online":{"date-parts":[[2019,9,25]]},"container-title":["American Journal of Nephrology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/503167","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/503167","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,4,23]],"date-time":"2025-04-23T15:58:40Z","timestamp":1745423920000},"score":1,"resource":{"primary":{"URL":"https:\/\/karger.com\/article\/doi\/10.1159\/000503167"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019]]},"references-count":0,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2019,11,14]]},"published-print":{"date-parts":[[2019,11,19]]}},"URL":"https:\/\/doi.org\/10.1159\/000503167","archive":["Portico"],"relation":{},"ISSN":["0250-8095","1421-9670"],"issn-type":[{"type":"print","value":"0250-8095"},{"type":"electronic","value":"1421-9670"}],"subject":[],"published":{"date-parts":[[2019]]}}}