{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,15]],"date-time":"2026-07-15T12:02:29Z","timestamp":1784116949155,"version":"3.55.0"},"reference-count":44,"publisher":"American Medical Association (AMA)","issue":"10","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JAMA Netw Open"],"abstract":"Importance<\/jats:title>Immune-mediated inflammatory diseases (IMIDs) and COVID-19 are independently associated with venous thromboembolisms (VTEs).<\/jats:p><\/jats:sec>Objective<\/jats:title>To determine if individuals with IMIDs are at higher risk of VTE following COVID-19 infection compared with individuals without IMIDs.<\/jats:p><\/jats:sec>Design, Setting, and Participants<\/jats:title>Population-based matched cohort study using multiple deterministically linked health administrative databases from Ontario, Canada, and including patients testing positive for COVID-19 between January 1, 2020, and December 30, 2021, and followed up until March 31, 2022. Individuals with IMIDs (n\u2009=\u200928\u202f440) who tested positive for COVID-19 were matched with up to 5 individuals without an IMID (n\u2009=\u2009126\u202f437) who tested positive for COVID-19. Matching was based on year of birth, sex, neighborhood income, and rural\/urban residence. Data analysis was performed from August 6, 2022, to August 21, 2023.<\/jats:p><\/jats:sec>Exposure<\/jats:title>Diagnosis of an IMID, identified using algorithms based on diagnostic codes, procedures, and specialist visits.<\/jats:p><\/jats:sec>Main Outcome and Measure<\/jats:title>The main outcome was estimated age- and sex-standardized incidence of VTE. Proportional cause-specific hazard models compared the risk of VTE in people with and without IMIDs. Death was a competing risk. Models adjusted for history of VTE, 2 or more doses of a COVID-19 vaccine 14 or more days prior to COVID-19 diagnosis, and the Charlson Comorbidity Index. Routinely collected health data were used, so the hypothesis tested was formulated after data collection but prior to being granted access to data.<\/jats:p><\/jats:sec>Results<\/jats:title>The study included 28\u202f440 individuals (16\u202f741 [58.9%] female; 11\u202f699 [41.1%] male) with an IMID diagnosed prior to first COVID-19 diagnosis, with a mean (SD) age of 52.1 (18.8) years at COVID-19 diagnosis. These individuals were matched to 126\u202f437 controls without IMIDs. The incidence of VTE within 6 months of COVID-19 diagnosis among 28\u202f440 individuals with an IMID was 2.64 (95% CI, 2.23-3.10) per 100\u202f000 person-days compared with 2.18 (95% CI, 1.99-2.38) per 100\u202f000 person-days among 126\u202f437 matched individuals without IMIDs. The VTE risk was not statistically significantly different among those with vs without IMIDs (adjusted hazard ratio, 1.12; 95% CI, 0.95-1.32).<\/jats:p><\/jats:sec>Conclusions and Relevance<\/jats:title>In this retrospective population-based cohort study of individuals with IMIDs following COVID-19, individuals with IMIDs did not have a higher risk of VTE compared with individuals without an IMID. These data provide reassurance to clinicians caring for individuals with IMIDs and COVID-19.<\/jats:p><\/jats:sec>","DOI":"10.1001\/jamanetworkopen.2023.37020","type":"journal-article","created":{"date-parts":[[2023,10,9]],"date-time":"2023-10-09T15:01:40Z","timestamp":1696863700000},"page":"e2337020","source":"Crossref","is-referenced-by-count":6,"title":["Venous Thromboembolism After COVID-19 Infection Among People With and Without Immune-Mediated Inflammatory Diseases"],"prefix":"10.1001","volume":"6","author":[{"given":"Rabia","family":"Khan","sequence":"first","affiliation":[{"name":"SickKids Inflammatory Bowel Disease Centre, Division of Gastroenterology, Hepatology and Nutrition, The Hospital for Sick Children, Toronto, Ontario, Canada"},{"name":"Child Health Evaluative Sciences, SickKids Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M. Ellen","family":"Kuenzig","sequence":"additional","affiliation":[{"name":"SickKids Inflammatory Bowel Disease Centre, Division of Gastroenterology, Hepatology and Nutrition, The Hospital for Sick Children, Toronto, Ontario, Canada"},{"name":"Child Health Evaluative Sciences, SickKids Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Furong","family":"Tang","sequence":"additional","affiliation":[{"name":"SickKids Inflammatory Bowel Disease Centre, Division of Gastroenterology, Hepatology and Nutrition, The Hospital for Sick Children, Toronto, Ontario, Canada"},{"name":"Child Health Evaluative Sciences, SickKids Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada"},{"name":"ICES, Toronto, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"James H. B.","family":"Im","sequence":"additional","affiliation":[{"name":"SickKids Inflammatory Bowel Disease Centre, Division of Gastroenterology, Hepatology and Nutrition, The Hospital for Sick Children, Toronto, Ontario, Canada"},{"name":"Child Health Evaluative Sciences, SickKids Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jessica","family":"Widdifield","sequence":"additional","affiliation":[{"name":"ICES, Toronto, Ontario, Canada"},{"name":"Sunnybrook Research Institute, Toronto, Ontario, Canada"},{"name":"Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jeffrey D.","family":"McCurdy","sequence":"additional","affiliation":[{"name":"Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada"},{"name":"Ottawa Hospital Research Institute, Ottawa, Ontario, Canada"},{"name":"Division of Gastroenterology, The Ottawa Hospital IBD Centre, Ottawa, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gilaad G.","family":"Kaplan","sequence":"additional","affiliation":[{"name":"Departments of Medicine and Community Health Sciences, University of Calgary, Calgary, Alberta, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eric I.","family":"Benchimol","sequence":"additional","affiliation":[{"name":"SickKids Inflammatory Bowel Disease Centre, Division of Gastroenterology, Hepatology and Nutrition, The Hospital for Sick Children, Toronto, Ontario, Canada"},{"name":"Child Health Evaluative Sciences, SickKids Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada"},{"name":"ICES, Toronto, Ontario, Canada"},{"name":"Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada"},{"name":"Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"10","published-online":{"date-parts":[[2023,10,9]]},"reference":[{"issue":"5","key":"zoi231081r1","doi-asserted-by":"publisher","first-page":"529","DOI":"10.1007\/s00281-017-0629-x","article-title":"Pathogenic human coronavirus infections: causes and consequences of cytokine storm and immunopathology.","volume":"39","author":"Channappanavar","year":"2017","journal-title":"Semin Immunopathol"},{"key":"zoi231081r2","doi-asserted-by":"publisher","first-page":"2037","DOI":"10.3389\/fimmu.2020.02037","article-title":"The immune response and immunopathology of COVID-19.","volume":"11","author":"Mortaz","year":"2020","journal-title":"Front Immunol"},{"key":"zoi231081r3","doi-asserted-by":"publisher","DOI":"10.3389\/fimmu.2022.992384","article-title":"Pathophysiological mechanisms of thrombosis in acute and long COVID-19.","volume":"13","author":"Jing","year":"2022","journal-title":"Front Immunol"},{"key":"zoi231081r4","doi-asserted-by":"publisher","first-page":"27","DOI":"10.1016\/j.thromres.2020.08.022","article-title":"Incidence of venous and arterial thromboembolic complications in COVID-19: a systematic review and meta-analysis.","volume":"196","author":"Kunutsor","year":"2020","journal-title":"Thromb Res"},{"key":"zoi231081r5","doi-asserted-by":"publisher","DOI":"10.1016\/j.eclinm.2020.100639","article-title":"Thromboembolism risk of COVID-19 is high and associated with a higher risk of mortality: a systematic review and meta-analysis.","volume":"29","author":"Malas","year":"2020","journal-title":"EClinicalMedicine"},{"key":"zoi231081r6","doi-asserted-by":"publisher","first-page":"n1931","DOI":"10.1136\/bmj.n1931","article-title":"Risk of thrombocytopenia and thromboembolism after covid-19 vaccination and SARS-CoV-2 positive testing: self-controlled case series study.","volume":"374","author":"Hippisley-Cox","year":"2021","journal-title":"BMJ"},{"key":"zoi231081r7","doi-asserted-by":"publisher","first-page":"2","DOI":"10.3899\/jrheum.091461","article-title":"Epidemiology of immune-mediated inflammatory diseases: incidence, prevalence, natural history, and comorbidities.","volume":"85","author":"El-Gabalawy","year":"2010","journal-title":"J Rheumatol Suppl"},{"issue":"3","key":"zoi231081r8","first-page":"171","article-title":"Autoimmune diseases and venous thromboembolism: a review of the literature.","volume":"2","author":"Z\u00f6ller","year":"2012","journal-title":"Am J Cardiovasc Dis"},{"issue":"3","key":"zoi231081r9","doi-asserted-by":"publisher","DOI":"10.1136\/rmdopen-2020-001392","article-title":"Risk of venous thromboembolism in immune-mediated inflammatory diseases: a UK matched cohort study.","volume":"6","author":"Galloway","year":"2020","journal-title":"RMD Open"},{"issue":"6","key":"zoi231081r10","doi-asserted-by":"publisher","first-page":"469","DOI":"10.1016\/j.crohns.2013.09.021","article-title":"Thromboembolic events and cardiovascular mortality in inflammatory bowel diseases: a meta-analysis of observational studies.","volume":"8","author":"Fumery","year":"2014","journal-title":"J Crohns Colitis"},{"issue":"9715","key":"zoi231081r11","doi-asserted-by":"publisher","first-page":"657","DOI":"10.1016\/S0140-6736(09)61963-2","article-title":"Venous thromboembolism during active disease and remission in inflammatory bowel disease: a cohort study.","volume":"375","author":"Grainge","year":"2010","journal-title":"Lancet"},{"issue":"11","key":"zoi231081r12","doi-asserted-by":"publisher","first-page":"1761","DOI":"10.1093\/ibd\/izaa002","article-title":"Risk of venous thromboembolism after hospital discharge in patients with inflammatory bowel disease: a population-based study.","volume":"26","author":"McCurdy","year":"2020","journal-title":"Inflamm Bowel Dis"},{"issue":"12","key":"zoi231081r13","doi-asserted-by":"publisher","first-page":"2031","DOI":"10.1093\/ecco-jcc\/jjab113","article-title":"Inflammatory bowel disease increases the risk of venous thromboembolism in children: a population-based matched cohort study.","volume":"15","author":"Kuenzig","year":"2021","journal-title":"J Crohns Colitis"},{"issue":"1","key":"zoi231081r14","doi-asserted-by":"publisher","first-page":"188","DOI":"10.1093\/rheumatology\/keaa262","article-title":"The risk and trend of pulmonary embolism and deep vein thrombosis in rheumatoid arthritis: a general population-based study.","volume":"60","author":"Li","year":"2021","journal-title":"Rheumatology (Oxford)"},{"issue":"3","key":"zoi231081r15","doi-asserted-by":"publisher","first-page":"297","DOI":"10.1007\/s10067-014-2492-7","article-title":"Risk of venous thromboembolism in patients with rheumatoid arthritis: a systematic review and meta-analysis.","volume":"33","author":"Ungprasert","year":"2014","journal-title":"Clin Rheumatol"},{"issue":"10","key":"zoi231081r16","doi-asserted-by":"publisher","first-page":"793","DOI":"10.1093\/qjmed\/hcu073","article-title":"Psoriasis and risk of venous thromboembolism: a systematic review and meta-analysis.","volume":"107","author":"Ungprasert","year":"2014","journal-title":"QJM"},{"issue":"6","key":"zoi231081r17","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0270142","article-title":"Increased risk of venous thromboembolism in patients with granulomatosis with polyangiitis: a population-based study.","volume":"17","author":"Marozoff","year":"2022","journal-title":"PLoS One"},{"issue":"4","key":"zoi231081r18","doi-asserted-by":"publisher","first-page":"444","DOI":"10.1111\/jth.12523","article-title":"The risk of venous thromboembolism in patients with multiple sclerosis: the Clinical Practice Research Datalink.","volume":"12","author":"Peeters","year":"2014","journal-title":"J Thromb Haemost"},{"issue":"10","key":"zoi231081r19","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pmed.1001885","article-title":"The REporting of studies Conducted using Observational Routinely-collected health Data (RECORD) statement.","volume":"12","author":"Benchimol","year":"2015","journal-title":"PLoS Med"},{"issue":"11","key":"zoi231081r20","doi-asserted-by":"publisher","first-page":"1490","DOI":"10.1136\/gut.2009.188383","article-title":"Increasing incidence of paediatric inflammatory bowel disease in Ontario, Canada: evidence from health administrative data.","volume":"58","author":"Benchimol","year":"2009","journal-title":"Gut"},{"issue":"8","key":"zoi231081r21","doi-asserted-by":"publisher","first-page":"887","DOI":"10.1016\/j.jclinepi.2014.02.019","article-title":"Validation of international algorithms to identify adults with inflammatory bowel disease in health administrative data from Ontario, Canada.","volume":"67","author":"Benchimol","year":"2014","journal-title":"J Clin Epidemiol"},{"issue":"8","key":"zoi231081r22","doi-asserted-by":"publisher","first-page":"1045","DOI":"10.1177\/1352458514556303","article-title":"Development and validation of an administrative data algorithm to estimate the disease burden and epidemiology of multiple sclerosis in Ontario, Canada.","volume":"21","author":"Widdifield","year":"2015","journal-title":"Mult Scler"},{"issue":"11","key":"zoi231081r23","doi-asserted-by":"publisher","first-page":"1644","DOI":"10.3899\/jrheum.190659","article-title":"Identifying and characterizing psoriasis and psoriatic arthritis patients in Ontario administrative data: a population-based study from 1991 to 2015.","volume":"47","author":"Eder","year":"2020","journal-title":"J Rheumatol"},{"issue":"10","key":"zoi231081r24","doi-asserted-by":"publisher","first-page":"1582","DOI":"10.1002\/acr.22031","article-title":"Accuracy of Canadian health administrative databases in identifying patients with rheumatoid arthritis: a validation study using the medical records of rheumatologists.","volume":"65","author":"Widdifield","year":"2013","journal-title":"Arthritis Care Res (Hoboken)"},{"key":"zoi231081r25","doi-asserted-by":"publisher","first-page":"216","DOI":"10.1186\/1471-2474-15-216","article-title":"An administrative data validation study of the accuracy of algorithms for identifying rheumatoid arthritis: the influence of the reference standard on algorithm performance.","volume":"15","author":"Widdifield","year":"2014","journal-title":"BMC Musculoskelet Disord"},{"issue":"4","key":"zoi231081r26","doi-asserted-by":"publisher","first-page":"364","DOI":"10.1177\/1358863X15573839","article-title":"The validity of ICD codes coupled with imaging procedure codes for identifying acute venous thromboembolism using administrative data.","volume":"20","author":"Alotaibi","year":"2015","journal-title":"Vasc Med"},{"issue":"11","key":"zoi231081r27","doi-asserted-by":"publisher","first-page":"1130","DOI":"10.1097\/01.mlr.0000182534.19832.83","article-title":"Coding algorithms for defining comorbidities in ICD-9-CM and ICD-10 administrative data.","volume":"43","author":"Quan","year":"2005","journal-title":"Med Care"},{"issue":"5","key":"zoi231081r28","doi-asserted-by":"publisher","first-page":"373","DOI":"10.1016\/0021-9681(87)90171-8","article-title":"A new method of classifying prognostic comorbidity in longitudinal studies: development and validation.","volume":"40","author":"Charlson","year":"1987","journal-title":"J Chronic Dis"},{"issue":"12","key":"zoi231081r29","doi-asserted-by":"publisher","first-page":"1288","DOI":"10.1016\/j.jclinepi.2004.03.012","article-title":"New ICD-10 version of the Charlson comorbidity index predicted in-hospital mortality.","volume":"57","author":"Sundararajan","year":"2004","journal-title":"J Clin Epidemiol"},{"issue":"6","key":"zoi231081r30","doi-asserted-by":"publisher","first-page":"613","DOI":"10.1016\/0895-4356(92)90133-8","article-title":"Adapting a clinical comorbidity index for use with ICD-9-CM administrative databases.","volume":"45","author":"Deyo","year":"1992","journal-title":"J Clin Epidemiol"},{"issue":"1","key":"zoi231081r31","doi-asserted-by":"publisher","first-page":"34","DOI":"10.1038\/s41533-017-0035-9","article-title":"Identifying individuals with physician-diagnosed chronic obstructive pulmonary disease in primary care electronic medical records: a retrospective chart abstraction study.","volume":"27","author":"Lee","year":"2017","journal-title":"NPJ Prim Care Respir Med"},{"issue":"3","key":"zoi231081r32","doi-asserted-by":"publisher","first-page":"160","DOI":"10.24095\/hpcdp.33.3.06","article-title":"Identifying cases of congestive heart failure from administrative data: a validation study using primary care patient records.","volume":"33","author":"Schultz","year":"2013","journal-title":"Chronic Dis Inj Can"},{"issue":"1","key":"zoi231081r33","doi-asserted-by":"publisher","DOI":"10.1136\/bmjdrc-2020-001224","article-title":"Validation of a type 1 diabetes algorithm using electronic medical records and administrative healthcare data to study the population incidence and prevalence of type 1 diabetes in Ontario, Canada.","volume":"8","author":"Weisman","year":"2020","journal-title":"BMJ Open Diabetes Res Care"},{"issue":"3","key":"zoi231081r34","doi-asserted-by":"publisher","first-page":"512","DOI":"10.2337\/diacare.25.3.512","article-title":"Diabetes in Ontario: determination of prevalence and incidence using a validated administrative data algorithm.","volume":"25","author":"Hux","year":"2002","journal-title":"Diabetes Care"},{"issue":"2","key":"zoi231081r35","doi-asserted-by":"publisher","first-page":"140","DOI":"10.1007\/BF03404588","article-title":"Socioeconomic misclassification in Ontario\u2019s health care registry.","volume":"94","author":"Glazier","year":"2003","journal-title":"Can J Public Health"},{"issue":"7","key":"zoi231081r36","doi-asserted-by":"crossref","first-page":"791","DOI":"10.1002\/(SICI)1097-0258(19970415)16:7<791::AID-SIM500>3.0.CO;2-#","article-title":"Confidence intervals for directly standardized rates: a method based on the gamma distribution.","volume":"16","author":"Fay","year":"1997","journal-title":"Stat Med"},{"issue":"5","key":"zoi231081r37","doi-asserted-by":"crossref","first-page":"1709","DOI":"10.1053\/j.gastro.2021.06.012","article-title":"Risk of venous thromboembolism among patients with inflammatory bowel disease who contract severe acute respiratory syndrome coronavirus 2.","volume":"161","author":"Mahmud","year":"2021","journal-title":"Gastroenterology"},{"issue":"3","key":"zoi231081r38","doi-asserted-by":"crossref","DOI":"10.1001\/jamanetworkopen.2023.2338","article-title":"Assessment of the risk of venous thromboembolism in nonhospitalized patients with COVID-19.","volume":"6","author":"Fang","year":"2023","journal-title":"JAMA Netw Open"},{"issue":"12","key":"zoi231081r39","doi-asserted-by":"crossref","first-page":"4643","DOI":"10.1093\/rheumatology\/keac209","article-title":"Autoimmune disease and COVID-19: a multicentre observational study in the United Kingdom.","volume":"61","author":"Arachchillage","year":"2022","journal-title":"Rheumatology (Oxford)"},{"key":"zoi231081r40","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1016\/j.thromres.2020.10.030","article-title":"Current estimates of the incidence of acute venous thromboembolic disease in Canada: a meta-analysis.","volume":"197","author":"Payne","year":"2021","journal-title":"Thromb Res"},{"key":"zoi231081r41","doi-asserted-by":"crossref","DOI":"10.3389\/fimmu.2022.1024924","article-title":"Duration of immunity to SARS-CoV-2 in children after natural infection or vaccination in the omicron and pre-omicron era: a systematic review of clinical and immunological studies.","volume":"13","author":"Buonsenso","year":"2023","journal-title":"Front Immunol"},{"issue":"3","key":"zoi231081r42","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1097\/BOR.0000000000000786","article-title":"COVID-19 and rheumatoid arthritis.","volume":"33","author":"D\u2019Silva","year":"2021","journal-title":"Curr Opin Rheumatol"},{"issue":"1","key":"zoi231081r43","doi-asserted-by":"crossref","first-page":"316","DOI":"10.1053\/j.gastro.2021.09.011","article-title":"Impact of medications on COVID-19 outcomes in inflammatory bowel disease: analysis of more than 6000 patients from an international registry.","volume":"162","author":"Ungaro","year":"2022","journal-title":"Gastroenterology"},{"issue":"6","key":"zoi231081r44","doi-asserted-by":"crossref","first-page":"650","DOI":"10.1055\/s-0036-1579642","article-title":"Thrombosis in autoimmune diseases: a role for immunosuppressive treatments?","volume":"42","author":"Silvestri","year":"2016","journal-title":"Semin Thromb Hemost"}],"container-title":["JAMA Network Open"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/jamanetwork.com\/journals\/jamanetworkopen\/articlepdf\/2810362\/khan_2023_oi_231081_1695928244.76461.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,9]],"date-time":"2023-10-09T15:01:48Z","timestamp":1696863708000},"score":1,"resource":{"primary":{"URL":"https:\/\/jamanetwork.com\/journals\/jamanetworkopen\/fullarticle\/2810362"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,10,9]]},"references-count":44,"journal-issue":{"issue":"10","published-print":{"date-parts":[[2023,10,2]]}},"URL":"https:\/\/doi.org\/10.1001\/jamanetworkopen.2023.37020","relation":{},"ISSN":["2574-3805"],"issn-type":[{"value":"2574-3805","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,10,9]]}}}