{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,22]],"date-time":"2026-04-22T10:36:08Z","timestamp":1776854168941,"version":"3.51.2"},"reference-count":32,"publisher":"Oxford University Press (OUP)","issue":"4","license":[{"start":{"date-parts":[[2026,4,22]],"date-time":"2026-04-22T00:00:00Z","timestamp":1776816000000},"content-version":"vor","delay-in-days":21,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Ministry of Health and Welfare, Republic of Korea","award":["HI22C0667"],"award-info":[{"award-number":["HI22C0667"]}]},{"name":"Korea Health Technology R&D Project"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,4,4]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Postoperative delirium is common in older surgical patients, but simple blood tests to identify risk are lacking. Plasma amyloid-\u03b2 oligomers measured by multimer detection (MDS-OA\u03b2) may reflect neurodegenerative vulnerability.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We enrolled 101 patients aged \u226565\u00a0years undergoing elective orthopaedic surgery with general anaesthesia. Blood was drawn preoperatively and at first delirium diagnosis or on postoperative Day 4 if no delirium. MDS-OA\u03b2 was quantified blinded. Delirium was assessed daily on postoperative Days 1\u20133 (DRS-R-98 and DSM). Propensity-score matching on APOE \u03b54 status and clinical covariates addressed Alzheimer-type vulnerability. Discrimination and thresholds (0.60, 0.72, 0.85\u00a0ng\/ml) were evaluated using logistic regression and ROC analyses.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Among 101 patients (44 with delirium; 57 without), preoperative MDS-OA\u03b2 concentrations were higher in those who developed delirium and correlated with delirium severity. In the overall cohort, preoperative MDS-OA\u03b2 discriminated delirium with an area under the curve of 0.855 (95% CI 0.777\u20130.919); in a pooled postoperative dataset (n\u2009=\u2009205), discrimination was similar (AUC 0.884, 95% CI 0.837\u20130.925). The dual-threshold approach identified a low-risk group with high negative predictive value and a high-risk group with high positive predictive value, leaving an intermediate group for closer observation.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Preoperative plasma MDS-OA\u03b2 may provide a scalable biomarker for perioperative risk stratification of postoperative delirium in older adults, supporting a dual-threshold strategy for targeted prevention and monitoring. Low MDS-OA\u03b2 values indicate lower risk but do not exclude POD; biomarker-guided stratification should complement, not replace, routine perioperative delirium surveillance.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/ageing\/afag106","type":"journal-article","created":{"date-parts":[[2026,4,6]],"date-time":"2026-04-06T11:19:29Z","timestamp":1775474369000},"source":"Crossref","is-referenced-by-count":0,"title":["Dual-threshold plasma A\u03b2 oligomerization for postoperative delirium risk stratification"],"prefix":"10.1093","volume":"55","author":[{"given":"YoungSoon","family":"Yang","sequence":"first","affiliation":[{"name":"Department of Neurology, Soonchunhyang University , Cheonan-si, Chungcheongnam-do 31151 ,","place":["Korea"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ki Jin","family":"Jung","sequence":"additional","affiliation":[{"name":"Department of Orthopedic Surgery, Soonchunhyang University , Cheonan-si, Chungcheongnam-do 31151 ,","place":["Korea"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yong Tae","family":"Kwak","sequence":"additional","affiliation":[{"name":"Department of Neurology, Hyoja Geriatric Hospital , 1-30, Jungbu-daero 874beon-gil, Giheung-gu, Yongin-si, Gyeonggi-do 17089 ,","place":["Korea"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"286","published-online":{"date-parts":[[2026,4,22]]},"reference":[{"key":"2026042205364392400_ref1","doi-asserted-by":"publisher","first-page":"328","DOI":"10.1001\/jamasurg.2018.5093","article-title":"Association between postoperative delirium and long-term cognitive function after major nonemergent surgery","volume":"154","author":"Austin","year":"2019","journal-title":"JAMA Surg"},{"key":"2026042205364392400_ref2","doi-asserted-by":"publisher","first-page":"111221","DOI":"10.1016\/j.jclinane.2023.111221","article-title":"Association between postoperative delirium and adverse outcomes in older surgical patients: A systematic review and meta-analysis","volume":"90","author":"Yan","year":"2023","journal-title":"J Clin Anesth"},{"key":"2026042205364392400_ref3","doi-asserted-by":"publisher","first-page":"e2519467","DOI":"10.1001\/jamanetworkopen.2025.19467","article-title":"Postoperative delirium in older adults undergoing non-cardiac surgery","volume":"8","author":"Lander","year":"2025","journal-title":"JAMA Netw Open"},{"key":"2026042205364392400_ref4","doi-asserted-by":"publisher","first-page":"1200","DOI":"10.1097\/SLA.0000000000002684","article-title":"CSF \u03b2-amyloid 1-42 concentration predicts delirium following elective arthroplasty surgery in an observational cohort study","volume":"269","author":"Cunningham","year":"2019","journal-title":"Ann Surg"},{"key":"2026042205364392400_ref5","doi-asserted-by":"publisher","first-page":"234","DOI":"10.1097\/EJA.0000000000001933","article-title":"Associations between Alzheimer\u2019s disease biomarkers and postoperative delirium or cognitive dysfunction: a meta-analysis and trial sequential analysis of prospective clinical trials","volume":"41","author":"Geng","year":"2024","journal-title":"Eur J Anaesthesiol"},{"key":"2026042205364392400_ref6","doi-asserted-by":"publisher","first-page":"93","DOI":"10.1016\/j.neurobiolaging.2017.09.020","article-title":"Association of postoperative delirium with markers of neurodegeneration and brain amyloidosis: A pilot study","volume":"61","author":"Rolandi","year":"2018","journal-title":"Neurobiol Aging"},{"key":"2026042205364392400_ref7","doi-asserted-by":"publisher","first-page":"e226","DOI":"10.1016\/j.bja.2021.12.014","article-title":"Amyloid deposition on positron emission tomography correlates with severity of perioperative delirium: a case-control pilot study","volume":"128","author":"Torres-Vel\u00e1zquez","year":"2022","journal-title":"Br J Anaesth"},{"key":"2026042205364392400_ref8","doi-asserted-by":"publisher","first-page":"546","DOI":"10.1016\/j.bja.2023.01.020","article-title":"Prospective analysis of plasma amyloid beta and postoperative delirium in the interventions for postoperative delirium: biomarker-3 study","volume":"130","author":"Payne","year":"2023","journal-title":"Br J Anaesth"},{"key":"2026042205364392400_ref9","doi-asserted-by":"publisher","first-page":"1386669","DOI":"10.3389\/fnagi.2024.1386669","article-title":"Intraoperative electroencephalogram patterns as predictors of postoperative delirium in older patients: a systematic review and meta-analysis","volume":"16","author":"Likhvantsev","year":"2024","journal-title":"Front Aging Neurosci"},{"key":"2026042205364392400_ref10","doi-asserted-by":"publisher","first-page":"31101","DOI":"10.1038\/s41598-024-82422-7","article-title":"Quantitative electroencephalography predicts postoperative delirium in adult cardiac surgical patients: a prospective observational study","volume":"14","author":"Guo","year":"2024","journal-title":"Sci Rep"},{"key":"2026042205364392400_ref11","first-page":"11343253","article-title":"Prediction of postoperative delirium in older adults from Preoperative Cognition and Occipital Alpha Power from Resting-State Electroencephalogram","volume":"11","author":"Ning","year":"2024","journal-title":"Front Med"},{"key":"2026042205364392400_ref12","first-page":"215","article-title":"Multimer detection system\u2013oligomeric amyloid-\u03b2 (MDS-OA\u03b2): a non-invasive blood-based biomarker to measure A\u03b2 oligomerization tendency","volume":"6","author":"Dominguez","year":"2022","journal-title":"J Alzheimers Dis Rep"},{"key":"2026042205364392400_ref13","doi-asserted-by":"publisher","first-page":"1400","DOI":"10.1186\/s13195-024-01400-3","article-title":"Plasma oligomer \u03b2-amyloid is associated with disease burden across the Alzheimer\u2019s disease continuum: an MDS-OA\u03b2 study","volume":"16","author":"Wang","year":"2024","journal-title":"Alzheimer\u2019s Res Ther"},{"key":"2026042205364392400_ref14","doi-asserted-by":"publisher","first-page":"146","DOI":"10.1038\/s43856-024-00690-w","article-title":"Blood-based quantification of A\u03b2 oligomers indicates impaired clearance from brain in ApoE \u03b54\u2013positive subjects","volume":"4","author":"Bl\u00f6meke","year":"2024","journal-title":"Commun Med (Lond)"},{"key":"2026042205364392400_ref15","doi-asserted-by":"publisher","first-page":"493","DOI":"10.3233\/JAD-200061","article-title":"Blood amyloid-\u03b2 oligomerization as a biomarker of Alzheimer\u2019s disease","volume":"75","author":"Youn","year":"2020","journal-title":"J Alzheimer\u2019s Dis"},{"key":"2026042205364392400_ref16","doi-asserted-by":"publisher","first-page":"237","DOI":"10.3390\/diagnostics10040237","article-title":"Association of plasma oligomerized beta-amyloid with neurocognitive battery using Korean version of CERAD in a health-screening population","volume":"10","author":"Lee","year":"2020","journal-title":"Diagnostics (Basel)"},{"key":"2026042205364392400_ref17","doi-asserted-by":"publisher","first-page":"749","DOI":"10.2147\/CIA.S312473","article-title":"Plasma amyloid-\u03b2 oligomerization tendency predicts amyloid PET positivity","volume":"16","author":"Pyun","year":"2021","journal-title":"Clin Interv Aging"},{"key":"2026042205364392400_ref18","doi-asserted-by":"publisher","first-page":"1291881","DOI":"10.3389\/fnagi.2023.1291881","article-title":"Association of plasma amyloid-\u03b2 oligomerization with theta\/beta EEG ratios in older adults","volume":"15","author":"Bae","year":"2023","journal-title":"Front Aging Neurosci"},{"key":"2026042205364392400_ref19","doi-asserted-by":"publisher","first-page":"13147","DOI":"10.1038\/s41598-025-97577-0","article-title":"The relationship between postoperative delirium and plasma amyloid beta oligomer","volume":"15","author":"Yang","year":"2025","journal-title":"Sci Rep"},{"key":"2026042205364392400_ref20","doi-asserted-by":"publisher","first-page":"1673496","DOI":"10.3389\/fmed.2025.1673496","article-title":"A prospective pilot study on plasma amyloid beta oligomers and postoperative delirium","volume":"12","author":"Yang","year":"2025","journal-title":"Front Med (Lausanne)"},{"key":"2026042205364392400_ref21","first-page":"127","article-title":"A principled approach to setting optimal diagnostic thresholds","volume":"33","author":"Irwin","year":"2011","journal-title":"Med Eng Phys"},{"key":"2026042205364392400_ref22","doi-asserted-by":"publisher","first-page":"304","DOI":"10.1093\/ije\/dyg054","article-title":"A grey zone for quantitative diagnostic and screening tests","volume":"32","author":"Coste","year":"2003","journal-title":"Int J Epidemiol"},{"key":"2026042205364392400_ref23","doi-asserted-by":"publisher","first-page":"30","DOI":"10.4306\/pi.2011.8.1.30","article-title":"Korean version of the delirium rating scale-Revised-98: reliability and validity","volume":"8","author":"Lee","year":"2011","journal-title":"Psychiatry Investig"},{"key":"2026042205364392400_ref24","doi-asserted-by":"publisher","first-page":"183","DOI":"10.1007\/s00401-015-1386-3","article-title":"Amyloid-beta oligomers in Alzheimer\u2019s disease pathogenesis, treatment, and diagnosis","volume":"129","author":"Viola","year":"2015","journal-title":"Acta Neuropathol"},{"key":"2026042205364392400_ref25","doi-asserted-by":"publisher","first-page":"8074","DOI":"10.1002\/alz.14315","article-title":"Head-to-head comparison of leading blood tests for Alzheimer\u2019s disease pathology and other AD-related outcomes","volume":"20","author":"Schindler","year":"2024","journal-title":"Alzheimers Dement"},{"key":"2026042205364392400_ref26","doi-asserted-by":"publisher","first-page":"3","DOI":"10.3892\/mmr.2015.3424","article-title":"Effect of the inhaled anesthetics isoflurane, sevoflurane and desflurane on the neuropathogenesis of Alzheimer's disease (Review)","volume":"12","author":"Jiang","year":"2015","journal-title":"Mol Med Rep"},{"key":"2026042205364392400_ref27","doi-asserted-by":"publisher","first-page":"703","DOI":"10.1097\/00000542-200409000-00019","article-title":"Inhaled anesthetic enhancement of amyloid-\u03b2 oligomerization and cytotoxicity","volume":"101","author":"Eckenhoff","year":"2004","journal-title":"Anesthesiology"},{"key":"2026042205364392400_ref28","doi-asserted-by":"publisher","first-page":"e0282214","DOI":"10.1371\/journal.pone.0282214","article-title":"Apolipoprotein E4 allele is genetically associated with risk of the short- and medium-term postoperative cognitive dysfunction: a meta-analysis and trial sequential analysis","volume":"18","author":"Hsiao","year":"2023","journal-title":"PLoS One"},{"key":"2026042205364392400_ref29","doi-asserted-by":"publisher","first-page":"879","DOI":"10.1093\/gerona\/glab184","article-title":"APOE \u03b54 genotypes increase risk of delirium during COVID-19\u2013related hospitalizations: evidence from a large UK cohort","volume":"77","author":"Kuo","year":"2022","journal-title":"J Gerontol A Biol Sci Med Sci"},{"key":"2026042205364392400_ref30","doi-asserted-by":"publisher","first-page":"492","DOI":"10.1016\/j.bja.2020.06.063","article-title":"Postoperative delirium: perioperative assessment, risk reduction, and management","volume":"125","author":"Jin","year":"2020","journal-title":"Br J Anaesth"},{"key":"2026042205364392400_ref31","doi-asserted-by":"publisher","first-page":"547","DOI":"10.1016\/j.ebiom.2018.10.021","article-title":"Surgery, neuroinflammation and cognitive impairment","volume":"37","author":"Alam","year":"2018","journal-title":"EBioMedicine"},{"key":"2026042205364392400_ref32","doi-asserted-by":"publisher","first-page":"644","DOI":"10.1097\/SLA.0000000000005287","article-title":"Is it time to assess neurological status before surgery to improve postoperative outcomes?","volume":"275","author":"Alam","year":"2022","journal-title":"Ann Surg"}],"container-title":["Age and Ageing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/ageing\/article-pdf\/55\/4\/afag106\/68134118\/afag106.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/ageing\/article-pdf\/55\/4\/afag106\/68134118\/afag106.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,22]],"date-time":"2026-04-22T09:36:50Z","timestamp":1776850610000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/ageing\/article\/doi\/10.1093\/ageing\/afag106\/8660725"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4]]},"references-count":32,"journal-issue":{"issue":"4","published-print":{"date-parts":[[2026,4,4]]}},"URL":"https:\/\/doi.org\/10.1093\/ageing\/afag106","relation":{},"ISSN":["0002-0729","1468-2834"],"issn-type":[{"value":"0002-0729","type":"print"},{"value":"1468-2834","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2026,4]]},"published":{"date-parts":[[2026,4]]},"article-number":"afag106"}}