{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T21:21:56Z","timestamp":1792790516203,"version":"4.5.0"},"reference-count":32,"publisher":"Cambridge University Press (CUP)","issue":"2","license":[{"start":{"date-parts":[[2023,8,10]],"date-time":"2023-08-10T00:00:00Z","timestamp":1691625600000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["cambridge.org"],"crossmark-restriction":true},"short-container-title":["Br J Nutr"],"published-print":{"date-parts":[[2024,1,28]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>The combined sandwich-ELISA (s-ELISA; VitMin Lab, Germany) and the Quansys Q-Plex\u2122 Human Micronutrient Array (7-Plex) are multiplex serum assays that are used to assess population micronutrient status in low-income countries. We aimed to compare the agreement of five analytes, <jats:italic>\u03b1<\/jats:italic>-1-acid glycoprotein (AGP), C-reactive protein (CRP), ferritin, retinol-binding protein 4 (RBP4) and soluble transferrin receptor (sTfR) as measured by the 7-Plex and the s-ELISA. Serum samples were collected between March 2016 and December 2017. Pregnant women (<jats:italic>n<\/jats:italic> 249) were recruited at primary healthcare clinics in Johannesburg, and serum samples were collected between March 2016 and December 2017. Agreement between continuous measurements was assessed by Bland\u2013Altman plots and concordance measures. Agreement in classifications of deficiency or inflammation was assessed by Cohen\u2019s kappa. Strong correlations (r &gt; 0\u00b780) were observed between the 7-Plex and s-ELISA for CRP and ferritin. Except for CRP, the 7-Plex assay gave consistently higher measurements than the s-ELISA. With the exception of CRP (Lin\u2019s \u03c1 = 0\u00b792), there was poor agreement between the two assays, with Lin\u2019s \u03c1 &lt; 0\u00b790. Discrepancies of test results difference between methods increased as the serum concentrations rose. Cohen\u2019s kappa for all the five analytes was &lt; 0\u00b781 and ranged from slight agreement (vitamin A deficiency) to substantial (inflammation and Fe deficiency) agreement. The 7-Plex 1.0 is a research and or surveillance tool with potential for use in low-resource laboratories but cannot be used interchangeably with the s-ELISA. Further optimising and validation is required to establish its interchangeability with other validated methods.<\/jats:p>","DOI":"10.1017\/s0007114523001782","type":"journal-article","created":{"date-parts":[[2023,8,10]],"date-time":"2023-08-10T08:22:52Z","timestamp":1691655772000},"page":"248-255","update-policy":"https:\/\/doi.org\/10.1017\/policypage","source":"Crossref","is-referenced-by-count":4,"title":["Comparison of test performance of two commonly used multiplex assays to measure micronutrient and inflammatory markers in serum: results from a survey among pregnant women in South Africa"],"prefix":"10.1017","volume":"131","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0070-3470","authenticated-orcid":false,"given":"Tsitsi Letwin","family":"Chimhashu","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hans","family":"Verhoef","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elizabeth A.","family":"Symington","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lizelle","family":"Zandberg","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jeannine","family":"Baumgartner","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Linda","family":"Malan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4829-0054","authenticated-orcid":false,"given":"Cornelius Marius","family":"Smuts","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5819-2488","authenticated-orcid":false,"given":"Edith J. M.","family":"Feskens","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8406-7592","authenticated-orcid":false,"given":"Alida","family":"Melse-Boonstra","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"56","published-online":{"date-parts":[[2023,8,10]]},"reference":[{"key":"S0007114523001782_ref3","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0185868"},{"key":"S0007114523001782_ref7","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0215782"},{"key":"S0007114523001782_ref9","doi-asserted-by":"publisher","DOI":"10.1515\/cclm-2016-0421"},{"key":"S0007114523001782_ref27","volume-title":"Serum Retinol Concentrations for Determining the Prevalence of Vitamin A Deficiency in Populations","year":"2011"},{"key":"S0007114523001782_ref6","doi-asserted-by":"publisher","DOI":"10.1002\/prca.201400130"},{"key":"S0007114523001782_ref2","doi-asserted-by":"publisher","DOI":"10.1093\/jn\/134.11.3127"},{"key":"S0007114523001782_ref19","doi-asserted-by":"publisher","DOI":"10.1186\/s12916-014-0256-5"},{"key":"S0007114523001782_ref21","doi-asserted-by":"publisher","DOI":"10.11613\/BM.2015.015"},{"key":"S0007114523001782_ref26","doi-asserted-by":"publisher","DOI":"10.2307\/2529310"},{"key":"S0007114523001782_ref11","doi-asserted-by":"publisher","DOI":"10.1177\/096228029900800204"},{"key":"S0007114523001782_ref23","doi-asserted-by":"publisher","DOI":"10.2307\/2532051"},{"key":"S0007114523001782_ref25","first-page":"307","article-title":"A proposal for strength-of-agreement criteria for Lins Concordance Correlation Coefficient","volume":"45","author":"McBride","year":"2005","journal-title":"NIWA Client Rep: HAM2005\u2013062"},{"key":"S0007114523001782_ref10","doi-asserted-by":"publisher","DOI":"10.1093\/jn\/nxab355"},{"key":"S0007114523001782_ref20","doi-asserted-by":"publisher","DOI":"10.1177\/1536867X0200200206"},{"key":"S0007114523001782_ref13","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0259509"},{"key":"S0007114523001782_ref12","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0110499"},{"key":"S0007114523001782_ref4","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0115164"},{"key":"S0007114523001782_ref32","doi-asserted-by":"publisher","DOI":"10.3945\/ajcn.117.155887"},{"key":"S0007114523001782_ref29","doi-asserted-by":"publisher","DOI":"10.3945\/jn.111.145805"},{"key":"S0007114523001782_ref28","unstructured":"28. World Health Organization (1996) Indicators for Assessing Vitamin A Deficiency and their Application in Monitoring and Evaluating Intervention Programmes. Geneva: World Health Organization."},{"key":"S0007114523001782_ref5","doi-asserted-by":"publisher","DOI":"10.1373\/clinchem.2009.135087"},{"key":"S0007114523001782_ref30","doi-asserted-by":"publisher","DOI":"10.3390\/nu9050430"},{"key":"S0007114523001782_ref1","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(20)31364-7"},{"key":"S0007114523001782_ref18","volume-title":"Global Prevalence of Vitamin A Deficiency in Populations at Risk 1995\u20132005: WHO Global Database on Vitamin A Deficiency","year":"2009"},{"key":"S0007114523001782_ref14","doi-asserted-by":"publisher","DOI":"10.1186\/s12884-018-1943-6"},{"key":"S0007114523001782_ref24","first-page":"23","article-title":"A note on concordance correlation coefficient","volume":"54","author":"Liao","year":"2000","journal-title":"PDA J Pharm Sci"},{"key":"S0007114523001782_ref17","unstructured":"17. Thurnham, DI & McCabe, GP (2012) Influence of Infection and Inflammation on Biomarkers of Nutritional Status with an Emphasis on Vitamin A and Iron. World Health Organization Report: Priorities in the Assessment of Vitamin A and Iron Status in Populations, Panama City, Panama. pp. 15\u201317. https:\/\/cdn.who.int\/media\/docs\/default-source\/micronutrients\/background-paper4-report-assessment-vitaandiron-status.pdf?sfvrsn=cc563dde_2 (accessed January 2023)."},{"key":"S0007114523001782_ref15","doi-asserted-by":"publisher","DOI":"10.1016\/j.tjnut.2022.11.001"},{"key":"S0007114523001782_ref16","volume-title":"Serum Ferritin Concentrations for the Assessment of Iron Status and Iron Deficiency in Populations","year":"2011"},{"key":"S0007114523001782_ref8","doi-asserted-by":"publisher","DOI":"10.3390\/diagnostics8010013"},{"key":"S0007114523001782_ref31","doi-asserted-by":"publisher","DOI":"10.1373\/clinchem.2004.041715"},{"key":"S0007114523001782_ref22","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(86)90837-8"}],"container-title":["British Journal of Nutrition"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.cambridge.org\/core\/services\/aop-cambridge-core\/content\/view\/S0007114523001782","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,4,5]],"date-time":"2024-04-05T09:19:04Z","timestamp":1712308744000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.cambridge.org\/core\/product\/identifier\/S0007114523001782\/type\/journal_article"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,8,10]]},"references-count":32,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2024,1,28]]}},"alternative-id":["S0007114523001782"],"URL":"https:\/\/doi.org\/10.1017\/s0007114523001782","relation":{},"ISSN":["0007-1145","1475-2662"],"issn-type":[{"value":"0007-1145","type":"print"},{"value":"1475-2662","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,8,10]]},"assertion":[{"value":"\u00a9 The Author(s), 2023. Published by Cambridge University Press on behalf of The Nutrition Society","name":"copyright","label":"Copyright","group":{"name":"copyright_and_licensing","label":"Copyright and Licensing"}},{"value":"This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http:\/\/creativecommons.org\/licenses\/by\/4.0\/), which permits unrestricted re-use, distribution and reproduction, provided the original article is properly cited.","name":"license","label":"License","group":{"name":"copyright_and_licensing","label":"Copyright and Licensing"}},{"value":"This content has been made available to all.","name":"free","label":"Free to read"}]}}