{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T09:55:32Z","timestamp":1790589332864,"version":"4.1.0"},"reference-count":29,"publisher":"Walter de Gruyter GmbH","issue":"11","license":[{"start":{"date-parts":[[2026,6,19]],"date-time":"2026-06-19T00:00:00Z","timestamp":1781827200000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,10,26]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec id=\"j_cclm-2026-0702_abs_001\">\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>\n                      External Quality Assessment (EQA) programmes conventionally use the Standard Deviation Index (SDI) with an analyte-independent acceptance criterion of\u00a0\u22122&lt;SDI&lt;+2, which does not account for biological variation or clinical relevance. We developed two novel metrics, the biologically calibrated tolerance index (SDI\n                      <jats:sub>RCV<\/jats:sub>\n                      ) and percentage SDI (pSDI), that integrate biological variation into EQA interpretation and quantified the sources of analytical imprecision through variance component analysis (VCA).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"j_cclm-2026-0702_abs_002\">\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Monthly EQA results from 12 consecutive survey cycles were analysed for 45 analytes (26 biochemistry, 19 immunoassay) in a single clinical laboratory. SDIRCV was defined as the ratio of the reference change value (RCV) to the peer-group coefficient of variation. The pSDI expressed EQA bias as a percentage of the RCV. A five-zone concordance framework was constructed by cross-tabulating conventional SDI and pSDI criteria. A three-level VCA decomposed total imprecision into within-month repeatability, between-month variation, and reagent lot-to-lot variation.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"j_cclm-2026-0702_abs_003\">\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Of 540 observations, nine (1.67\u202f%) met the Biologically Significant, Statistically Undetected Deviation criterion (\u22122&lt;SDI&lt;+2 yet pSDI\u2265+100\u202f% or\u00a0\u2264\u2212100\u202f%), indicating clinically significant bias despite acceptable SDI. Four observations (0.74\u202f%) showed Clinically Inconsequential SDI Exceedance (SDI\u2265+3 or\u00a0\u2264\u22123 yet\u00a0\u2212100\u202f%&lt;pSDI&lt;+100\u202f%). Eleven analytes (24\u202f%) had median SDI\n                      <jats:sub>RCV<\/jats:sub>\n                      &lt;2.0, defining a persistent vulnerability zone. Lot-to-lot variation accounted for a median of 23.6\u202f% of the total variance, exceeding 50\u202f% for six analytes.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"j_cclm-2026-0702_abs_004\">\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>\n                      SDI\n                      <jats:sub>RCV<\/jats:sub>\n                      and pSDI detect both false acceptance and false rejection inherent in conventional EQA criteria, offering a biologically grounded framework for aligning laboratory quality assessment with clinical\u00a0needs.\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.1515\/cclm-2026-0702","type":"journal-article","created":{"date-parts":[[2026,6,18]],"date-time":"2026-06-18T05:55:47Z","timestamp":1781762147000},"page":"2430-2441","source":"Crossref","is-referenced-by-count":0,"title":["Is statistical evaluation sufficient? New external quality assessment performance metrics through clinical performance"],"prefix":"10.1515","volume":"64","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4303-7837","authenticated-orcid":false,"given":"Halil \u0130brahim","family":"Akbay","sequence":"first","affiliation":[{"name":"Department of Medical Biochemistry , Faculty of Medicine, Van Y\u00fcz\u00fcnc\u00fc Y\u0131l University , Van , T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0756-7723","authenticated-orcid":false,"given":"Elvar","family":"Theodorsson","sequence":"additional","affiliation":[{"name":"Department of Biomedical and Clinical Sciences , Link\u00f6ping University , Link\u00f6ping , Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9202-4944","authenticated-orcid":false,"given":"Hamit Hakan","family":"Alp","sequence":"additional","affiliation":[{"name":"Department of Medical Biochemistry , Faculty of Medicine, Van Y\u00fcz\u00fcnc\u00fc Y\u0131l University , Van , T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"374","published-online":{"date-parts":[[2026,6,19]]},"reference":[{"key":"2026092809015483151_j_cclm-2026-0702_ref_001","doi-asserted-by":"crossref","unstructured":"Sciacovelli, L, Secchiero, S, Padoan, A, Plebani, M. External quality assessment programs in the context of ISO 15189 accreditation. Clin Chem Lab Med 2018;56:1644\u201354. https:\/\/doi.org\/10.1515\/cclm-2017-1179.","DOI":"10.1515\/cclm-2017-1179"},{"key":"2026092809015483151_j_cclm-2026-0702_ref_002","doi-asserted-by":"crossref","unstructured":"Ricos, C, Fernandez-Calle, P, Perich, C, Sandberg, S. External quality control in laboratory medicine. Progresses and future. Adv Lab Med 2022;3:221\u201342. https:\/\/doi.org\/10.1515\/almed-2022-0058.","DOI":"10.1515\/almed-2022-0058"},{"key":"2026092809015483151_j_cclm-2026-0702_ref_003","doi-asserted-by":"crossref","unstructured":"Niraula, A, Bataju, M. External quality assessment practices in clinical biochemistry laboratory: what is the need? Kathmandu Univ Med J (KUMJ) 2020;18:86\u201392. https:\/\/doi.org\/10.3126\/kumj.v18i1.34660.","DOI":"10.3126\/kumj.v18i1.34660"},{"key":"2026092809015483151_j_cclm-2026-0702_ref_004","unstructured":"Miller, W, Sandberg, S. 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