{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T01:37:57Z","timestamp":1787017077965,"version":"build-2736575974"},"reference-count":30,"publisher":"BMJ","issue":"11","license":[{"start":{"date-parts":[[2025,11,4]],"date-time":"2025-11-04T00:00:00Z","timestamp":1762214400000},"content-version":"unspecified","delay-in-days":3,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000024","name":"Canadian Institutes of Health Research","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100000024","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2025,10,1]]},"published-print":{"date-parts":[[2025,11]]},"abstract":"<jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>\n                      To assess the validity of the\n                      <jats:italic>International Classification of Diseases, 10th Revision<\/jats:italic>\n                      (ICD-10) healthcare database diagnosis codes for lithium toxicity at hospital admission in Ontario, Canada.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Design<\/jats:title>\n                    <jats:p>Population-based retrospective validation study.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Setting<\/jats:title>\n                    <jats:p>A total of 152 hospitals linked to a provincial laboratory database in Ontario, Canada, from 2007 to 2023.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Participants<\/jats:title>\n                    <jats:p>Patients 50 years of age or older taking lithium with hospital-based serum lithium laboratory measurements during admission to the hospital (n=2804).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Outcome measures<\/jats:title>\n                    <jats:p>Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) comparing an ICD-10 diagnostic coding algorithm for lithium toxicity to a serum lithium concentration of 1.5\u2009mmol\/L or more. The codes used in the algorithm were T568, T435, Y495, X41 and X49. Serum lithium values and changes in the concentration of serum lithium from baseline levels in patients with and without a diagnosis code for lithium toxicity (code-positive and code-negative, respectively).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>The sensitivity of the ICD-10 coding algorithm for identifying a serum lithium level\u22651.5\u2009mmol\/L was 84% (95% CI 81% to 87%). The specificity and the NPV were over 88%, and the PPV was 63% (95% CI 60% to 66%). The median (IQR) serum lithium measurement in code-positive patients was 1.7 (1.2 to 2.2)\u2009mmol\/L, and it was 0.6 (0.4 to 0.9)\u2009mmol\/L in code-negative patients. The median (IQR) increase in serum lithium concentration compared with the most recent prehospital baseline values was 0.7 (0.2 to 1.3)\u2009mmol\/L in code-positive patients and 0.0 (\u22120.2 to 0.2)\u2009mmol\/L in code-negative patients.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>In Ontario, the sensitivity of the ICD-10 coding algorithms was moderate for identifying a serum lithium level\u22651.5\u2009mmol\/L at hospital admission. The presence or absence of the ICD-10 codes for lithium toxicity at hospital admission successfully differentiated two groups of patients with distinct serum lithium measurements.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2024-097196","type":"journal-article","created":{"date-parts":[[2025,11,4]],"date-time":"2025-11-04T13:44:17Z","timestamp":1762263857000},"page":"e097196","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":1,"title":["Validity of the International Classification of Diseases, 10th Revision codes for lithium toxicity in adult patients at hospital admission: a cohort study in Canada"],"prefix":"10.1136","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9562-1760","authenticated-orcid":false,"given":"Fatemeh","family":"Ahmadi","sequence":"first","affiliation":[{"name":"Western University Schulich School of Medicine & Dentistry, London, Ontario, Canada"},{"name":"ICES, Toronto, Ontario, Canada"},{"name":"London Health Sciences Centre and London Health Sciences Centre Research Institute, London, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Flory Tsobo","family":"Muanda","sequence":"additional","affiliation":[{"name":"Western University Schulich School of Medicine & Dentistry, London, Ontario, Canada"},{"name":"ICES, Toronto, Ontario, Canada"},{"name":"London Health Sciences Centre and London Health Sciences Centre Research Institute, London, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jennifer","family":"Ehiwario","sequence":"additional","affiliation":[{"name":"ICES, Toronto, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eric","family":"McArthur","sequence":"additional","affiliation":[{"name":"ICES, Toronto, Ontario, Canada"},{"name":"London Health Sciences Centre and London Health Sciences Centre Research Institute, London, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Racquel","family":"Jandoc","sequence":"additional","affiliation":[{"name":"ICES, Toronto, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Justin","family":"Slater","sequence":"additional","affiliation":[{"name":"ICES, Toronto, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Akshaya","family":"Vasudev","sequence":"additional","affiliation":[{"name":"Western University Schulich School of Medicine & Dentistry, London, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Matthew A","family":"Weir","sequence":"additional","affiliation":[{"name":"Western University Schulich School of Medicine & Dentistry, London, Ontario, Canada"},{"name":"ICES, Toronto, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6767-1197","authenticated-orcid":false,"given":"Edward G","family":"Clark","sequence":"additional","affiliation":[{"name":"Medicine, University of Ottawa, Ottawa, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Soham","family":"Rej","sequence":"additional","affiliation":[{"name":"Psychiatry, Jewish General Hospital, Montreal, Qu\u00e9bec, Canada"},{"name":"Psychiatry, Lady Davis Institute for Medical Research, Montreal, Qu\u00e9bec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nathan","family":"Herrmann","sequence":"additional","affiliation":[{"name":"Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amit X","family":"Garg","sequence":"additional","affiliation":[{"name":"ICES, Toronto, Ontario, Canada"},{"name":"London Health Sciences Centre and London Health Sciences Centre Research Institute, London, Ontario, Canada"},{"name":"Department of Epidemiology and Biostatistics, Western University Schulich School of Medicine & Dentistry, London, Ontario, Canada"},{"name":"Department of Medicine, Western University Schulich School of Medicine & Dentistry, London, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2025,11,4]]},"reference":[{"key":"2025120413252357000_15.11.e097196.1","doi-asserted-by":"publisher","DOI":"10.9778\/cmajo.20170036"},{"key":"2025120413252357000_15.11.e097196.2","first-page":"1","article-title":"ICD-10 coding variability within an academic pediatric ortho-paedic practice","volume":"1","author":"Murphy","year":"2021","journal-title":"Medpress Surg"},{"key":"2025120413252357000_15.11.e097196.3","first-page":"912","article-title":"Accuracy and Completeness of Clinical Coding Using ICD-10 for Ambulatory Visits","volume":"2017","author":"Horsky","year":"2017","journal-title":"AMIA Annu Symp Proc"},{"key":"2025120413252357000_15.11.e097196.4","doi-asserted-by":"crossref","first-page":"1220","DOI":"10.1080\/15563650.2019.1677022","article-title":"2018 Annual Report of the American Association of Poison Control Centers\u2019 National Poison Data System (NPDS): 36th Annual Report","volume":"57","author":"Gummin","year":"2019","journal-title":"Clin Toxicol (Phila)"},{"key":"2025120413252357000_15.11.e097196.5","doi-asserted-by":"publisher","DOI":"10.1080\/15563650.2020.1834219"},{"key":"2025120413252357000_15.11.e097196.6","doi-asserted-by":"publisher","DOI":"10.1111\/j.1532-5415.2004.52221.x"},{"key":"2025120413252357000_15.11.e097196.7","doi-asserted-by":"publisher","DOI":"10.2215\/CJN.10021014"},{"key":"2025120413252357000_15.11.e097196.8","doi-asserted-by":"publisher","DOI":"10.1177\/0885066616651582"},{"key":"2025120413252357000_15.11.e097196.9","doi-asserted-by":"publisher","DOI":"10.1038\/sj.ki.5002578"},{"key":"2025120413252357000_15.11.e097196.10","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2012-001821","article-title":"Validity of the International Classification of Diseases, Tenth Revision code for acute kidney injury in elderly patients at presentation to the emergency department and at hospital admission","volume":"2","author":"Hwang","year":"2012","journal-title":"BMJ Open"},{"key":"2025120413252357000_15.11.e097196.11","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2012-002011","article-title":"Validity of the International Classification of Diseases 10th revision code for hyperkalaemia in elderly patients at presentation to an emergency department and at hospital admission","volume":"2","author":"Fleet","year":"2012","journal-title":"BMJ Open"},{"key":"2025120413252357000_15.11.e097196.12","doi-asserted-by":"publisher","DOI":"10.2165\/00139709-200625040-00003"},{"key":"2025120413252357000_15.11.e097196.13","unstructured":"Hedya SA , Avula A , Swoboda HD . Lithium toxicity. 2018."},{"key":"2025120413252357000_15.11.e097196.14","unstructured":"Statistics Canada . Table 17-10-0005-01 population estimates on july 1, by age and gender. Available: https:\/\/www150.statcan.gc.ca\/t1\/tbl1\/en\/tv.action?pid=1710000501 [Accessed 10 Sep 2024]."},{"key":"2025120413252357000_15.11.e097196.15","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2016-012799","article-title":"STARD 2015 guidelines for reporting diagnostic accuracy studies: explanation and elaboration","volume":"6","author":"Cohen","year":"2016","journal-title":"BMJ Open"},{"key":"2025120413252357000_15.11.e097196.16","doi-asserted-by":"crossref","DOI":"10.1136\/bmj.k3532","article-title":"The reporting of studies conducted using observational routinely collected health data statement for pharmacoepidemiology (RECORD-PE)","volume":"363","author":"Langan","year":"2018","journal-title":"BMJ"},{"key":"2025120413252357000_15.11.e097196.17","first-page":"67","article-title":"Coding accuracy of administrative drug claims in the Ontario Drug Benefit database","volume":"10","author":"Levy","year":"2003","journal-title":"Can J Clin Pharmacol"},{"key":"2025120413252357000_15.11.e097196.18","doi-asserted-by":"crossref","first-page":"1037","DOI":"10.1002\/aur.2491","article-title":"Assessing the validity of administrative health data for the identification of children and youth with autism spectrum disorder in Ontario","volume":"14","author":"Brooks","year":"2021","journal-title":"Autism Res"},{"key":"2025120413252357000_15.11.e097196.19","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1016\/j.jcjd.2020.08.106","article-title":"Validity of Hospital Codes for Obesity in Ontario, Canada","volume":"45","author":"Clemens","year":"2021","journal-title":"Can J Diabetes"},{"key":"2025120413252357000_15.11.e097196.20","doi-asserted-by":"publisher","DOI":"10.1017\/cjn.2016.278"},{"key":"2025120413252357000_15.11.e097196.21","doi-asserted-by":"crossref","first-page":"E73","DOI":"10.25011\/cim.v39i2.26483","article-title":"Validation of Carotid Artery Revascularization Coding in Ontario Health Administrative Databases","volume":"39","author":"Hussain","year":"2016","journal-title":"Clin Invest Med"},{"key":"2025120413252357000_15.11.e097196.22","doi-asserted-by":"publisher","DOI":"10.1016\/j.cjca.2013.07.676"},{"key":"2025120413252357000_15.11.e097196.23","doi-asserted-by":"publisher","DOI":"10.1046\/j.1440-1614.2001.00963.x"},{"key":"2025120413252357000_15.11.e097196.24","first-page":"258","article-title":"Chronic lithium toxicity: Considerations and systems analysis","volume":"66","author":"MacLeod-Glover","year":"2020","journal-title":"Can Fam Physician"},{"key":"2025120413252357000_15.11.e097196.25","doi-asserted-by":"publisher","DOI":"10.2165\/00002512-200016030-00002"},{"key":"2025120413252357000_15.11.e097196.26","doi-asserted-by":"crossref","first-page":"689","DOI":"10.1111\/bdi.12331","article-title":"A report on older-age bipolar disorder from the International Society for Bipolar Disorders Task Force","volume":"17","author":"Sajatovic","year":"2015","journal-title":"Bipolar Disord"},{"key":"2025120413252357000_15.11.e097196.27","doi-asserted-by":"crossref","first-page":"201","DOI":"10.1007\/s40261-017-0598-9","article-title":"Lithium Toxicity in Older Adults: a Systematic Review of Case Reports","volume":"38","author":"Sun","year":"2018","journal-title":"Clin Drug Investig"},{"key":"2025120413252357000_15.11.e097196.28","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1097\/YIC.0000000000000341","article-title":"Resurrecting the discussion on neurotoxicity of lithium at therapeutic levels","volume":"36","author":"Jha","year":"2021","journal-title":"Int Clin Psychopharmacol"},{"key":"2025120413252357000_15.11.e097196.29","doi-asserted-by":"crossref","first-page":"e155","DOI":"10.1016\/j.amjmed.2019.09.021","article-title":"Looking Beyond Numbers: Lithium Toxicity Within Therapeutic Levels","volume":"133","author":"Jacob","year":"2020","journal-title":"Am J Med"},{"key":"2025120413252357000_15.11.e097196.30","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMOA2102953\/SUPPL_FILE\/NEJMOA2102953_DISCLOSURES.PDF"}],"container-title":["BMJ Open"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bmjopen-2024-097196","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,4]],"date-time":"2025-12-04T21:25:42Z","timestamp":1764883542000},"score":1,"resource":{"primary":{"URL":"https:\/\/bmjopen.bmj.com\/lookup\/doi\/10.1136\/bmjopen-2024-097196"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,11]]},"references-count":30,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2025,11,4]]},"published-print":{"date-parts":[[2025,11]]}},"alternative-id":["10.1136\/bmjopen-2024-097196"],"URL":"https:\/\/doi.org\/10.1136\/bmjopen-2024-097196","relation":{},"ISSN":["2044-6055","2044-6055"],"issn-type":[{"value":"2044-6055","type":"print"},{"value":"2044-6055","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,11]]}}}