{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,11]],"date-time":"2026-10-11T16:47:13Z","timestamp":1791737233968,"version":"4.3.4"},"reference-count":35,"publisher":"Springer Science and Business Media LLC","license":[{"start":{"date-parts":[[2026,10,11]],"date-time":"2026-10-11T00:00:00Z","timestamp":1791676800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2026,10,11]],"date-time":"2026-10-11T00:00:00Z","timestamp":1791676800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["J. Racial and Ethnic Health Disparities"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>In 2024, COVID-19 entered a post-emergency phase, but in-hospital mortality remains a relevant public health concern in Brazil. As population immunity, vaccination, and clinical management evolved, the hierarchy of mortality predictors may have shifted from traditional metabolic risk factors toward clinical severity and social vulnerability. This study aimed to identify sociodemographic, clinical, management, and vaccination-related variables associated with in-hospital COVID-19 mortality among adults in Brazil in 2024, with emphasis on racial and socioeconomic inequities.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>A retrospective national cohort study was conducted using the SIVEP-Gripe surveillance database. Adults aged\u2009\u2265\u200918 years hospitalized with laboratory-confirmed COVID-19 between January and December 2024 were included. The primary analysis was restricted to patients with observed hospital outcomes, resulting in an analytical sample of 19,718 individuals. Crude and adjusted associations were estimated using binary logistic regression. Race\/color was modeled using White patients as the reference category. Robustness to unmeasured confounding was assessed using E-values, and model performance was evaluated using AUC-ROC.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      The in-hospital fatality rate was 23.5% (\n                      <jats:italic>n<\/jats:italic>\n                      \u2009=\u20094,633). Invasive ventilatory support was the strongest predictor of death (aOR: 7.574; 95% CI: 6.801\u20138.435; E-value: 4.95). Black patients had higher odds of death compared with White patients (aOR: 1.506; 95% CI: 1.233\u20131.838; E-value: 1.76), as did Pardo\/mixed-race patients, although with lower magnitude (aOR: 1.103; 95% CI: 1.006\u20131.209). A strong educational gradient was observed, with illiterate patients having more than twice the odds of death compared with those with higher education (aOR: 2.148; 95% CI: 1.628\u20132.833). Incomplete COVID-19 vaccination was also associated with increased mortality, while influenza vaccination was associated with lower odds of death. Diabetes, obesity, and chronic cardiovascular disease were not independently associated with mortality after adjustment.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>In-hospital COVID-19 mortality in Brazil in 2024 was shaped by respiratory severity, incomplete vaccination, and persistent racial and socioeconomic inequities. Although structural racism was not directly measured, the persistence of racialized mortality differences after adjustment is compatible with structural barriers in the healthcare pathway. Equity-oriented strategies should complement vaccination and clinical management to reduce preventable mortality among socially vulnerable populations.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1007\/s40615-026-03093-w","type":"journal-article","created":{"date-parts":[[2026,10,11]],"date-time":"2026-10-11T16:39:41Z","timestamp":1791736781000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Racial and Socioeconomic Inequities in COVID-19 In-Hospital Mortality in Brazil in the Post-Emergency Era: A National Cohort Study of 19,718 Hospitalized Adults in 2024"],"prefix":"10.1007","author":[{"given":"Daniele Melo","family":"Sardinha","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tamires","family":"de Nazar\u00e9 Soares","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marcos Jess\u00e9 Abrah\u00e3o","family":"Silva","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lidiane Assun\u00e7\u00e3o","family":"de Vasconcelos","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luany Rafaele","family":"da Concei\u00e7\u00e3o Cruz","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Karina Faine Freitas","family":"Takeda","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Natasha Cristina Oliveira","family":"Andrade","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Suziane do Socorro","family":"dos Santosa","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Felipe Costa","family":"Soares","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Neiva Jos\u00e9 da Luz","family":"Dias","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yan Corr\u00eaa","family":"Rodrigues","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ilma Pastana","family":"Ferreira","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Monica Cust\u00f3dia do Couto Abreu","family":"Pamplona","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ivonete Vieira Pereira","family":"Peixoto","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luana Nepomuceno Gondim Costa","family":"Limaa","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,10,11]]},"reference":[{"key":"3093_CR1","doi-asserted-by":"publisher","first-page":"100503","DOI":"10.1016\/j.ijregi.2024.100503","volume":"14","author":"LFL Tort","year":"2025","unstructured":"Tort LFL, de Ara\u00fajo MF, Arantes I, Martins JS, Gomes M, de Carvalho FC, et al. SARS-CoV-2 Omicron XBB infections boost cross-variant neutralizing antibodies, potentially explaining the observed delay of the JN.1 wave in some Brazilian regions. IJID Reg [Internet]. 2025;14:100503. https:\/\/doi.org\/10.1016\/j.ijregi.2024.100503.","journal-title":"IJID Reg [Internet]"},{"key":"3093_CR2","doi-asserted-by":"publisher","first-page":"100465","DOI":"10.1016\/j.lana.2023.100465","volume":"20","author":"CVB dos Santos","year":"2023","unstructured":"dos Santos CVB, Valiati NCM, de Noronha TG, Porto VBG, Pacheco AG, Freitas LP, et al. The effectiveness of COVID-19 vaccines against severe cases and deaths in Brazil from 2021 to 2022: a registry-based study. Lancet Reg Heal - Am [Internet]. 2023;20:100465. https:\/\/doi.org\/10.1016\/j.lana.2023.100465.","journal-title":"Lancet Reg Heal - Am [Internet]"},{"key":"3093_CR3","doi-asserted-by":"publisher","first-page":"106418","DOI":"10.1016\/j.jinf.2025.106418","volume":"90","author":"M Silva Souza","year":"2025","unstructured":"Silva Souza M, Pires Farias J, de Souza Ferreira LC, Amorim JH. Declining COVID-19 vaccination coverage in Brazil: A global health warning. J Infect [Internet]. 2025;90:106418. https:\/\/doi.org\/10.1016\/j.jinf.2025.106418.","journal-title":"J Infect [Internet]"},{"key":"3093_CR4","doi-asserted-by":"publisher","first-page":"77","DOI":"10.1186\/s12992-019-0523-5","volume":"15","author":"CV Machado","year":"2019","unstructured":"Machado CV, Silva GA. e. Political struggles for a universal health system in Brazil: successes and limits in the reduction of inequalities. Global Health [Internet]. 2019;15:77. . https:\/\/doi.org\/10.1186\/s12992-019-0523-5","journal-title":"Global Health [Internet]"},{"key":"3093_CR5","doi-asserted-by":"publisher","first-page":"85","DOI":"10.11606\/s1518-8787.2022056004178","volume":"56","author":"MY Ichihara","year":"2022","unstructured":"Ichihara MY, Ferreira AJF, Teixeira CSS, Alves FJO, Rocha AS, Di\u00f3genes VHD, et al. Mortality inequalities measured by socioeconomic indicators in Brazil: a scoping review. Rev Saude Publica [Internet]. 2022;56:85. https:\/\/doi.org\/10.11606\/s1518-8787.2022056004178.","journal-title":"Rev Saude Publica [Internet]"},{"key":"3093_CR6","doi-asserted-by":"publisher","unstructured":"Nogales Vasconcelos AM, Ishitani L, Abreu DMX, Fran\u00e7a E. Covid Adult Mortality in Brazil: An Analysis of Multiple Causes of Death. Front Public Heal [Internet]. 2022;9. . https:\/\/doi.org\/10.3389\/fpubh.2021.788932","DOI":"10.3389\/fpubh.2021.788932"},{"key":"3093_CR7","doi-asserted-by":"publisher","unstructured":"Lima IRda, Oliveira SB, Pascoal AJF, Santos LM, Santos FS, Santos Neto LH et al. M,. Factors associated with death in severe patients with COVID-19\/diabetes mellitus in Brazil. Rev Bras Enferm [Internet]. 2025;78. https:\/\/doi.org\/10.1590\/0034-7167-2024-0361","DOI":"10.1590\/0034-7167-2024-0361"},{"key":"3093_CR8","doi-asserted-by":"publisher","unstructured":"Sardinha DM, Rodrigues YC, Ferreira AL, da, Lima S, Guimar\u00e3es KVB, PS de, e RJ, Lima LNGC. Predictors of Death for Hospitalized Patients with COVID-19 in the First Year of the Pandemic in Northern Brazil - A Retrospective Study. Arch Curr Res Int. 2023;23:17\u201333. . . https:\/\/doi.org\/10.9734\/acri\/2023\/v23i5572","DOI":"10.9734\/acri\/2023\/v23i5572"},{"key":"3093_CR9","doi-asserted-by":"publisher","first-page":"222","DOI":"10.1007\/s40615-023-01866-1","volume":"12","author":"L Santos Silva","year":"2025","unstructured":"Santos Silva L, da Concei\u00e7\u00e3o Barbosa RB, Lima JP, Castro-Alves J, Ribeiro-Alves M. Racial Inequalities in the Health Establishment Access to the Treatment of COVID-19 in Brazil in 2020. J Racial Ethn Heal Disparities [Internet]. 2025;12:222\u201333. https:\/\/doi.org\/10.1007\/s40615-023-01866-1.","journal-title":"J Racial Ethn Heal Disparities [Internet]"},{"key":"3093_CR10","doi-asserted-by":"publisher","first-page":"238","DOI":"10.1186\/s12939-023-02037-8","volume":"22","author":"MC Portela","year":"2023","unstructured":"Portela MC, Martins M, Lima SML, de Andrade CLT, de Aguiar Pereira CC. COVID-19 inpatient mortality in Brazil from 2020 to 2022: a cross-sectional overview study based on secondary data. Int J Equity Health [Internet]. 2023;22:238. https:\/\/doi.org\/10.1186\/s12939-023-02037-8.","journal-title":"Int J Equity Health [Internet]"},{"key":"3093_CR11","doi-asserted-by":"publisher","first-page":"e1001885","DOI":"10.1371\/journal.pmed.1001885","volume":"12","author":"EI Benchimol","year":"2015","unstructured":"Benchimol EI, Smeeth L, Guttmann A, Harron K, Moher D, Petersen I, et al. The REporting of studies Conducted using Observational Routinely-collected health Data (RECORD) statement. PLoS Med. 2015;12:e1001885. https:\/\/doi.org\/10.1371\/journal.pmed.1001885.","journal-title":"PLoS Med"},{"key":"3093_CR12","unstructured":"Brasil MdaS, Ficha de notifica\u00e7\u00e3o. SIVEP-GRIPE 2024 [Internet]. SIVEP-GRIPE. 2024. p. 2. https:\/\/opendatasus.saude.gov.br\/dataset\/39a4995f-4a6e-440f-8c8f-b00c81fae0d0\/resource\/9f0edb83-f8c2-4b53-99c1-099425ab634c\/download\/ficha-de-notificacao-2025.pdf"},{"key":"3093_CR13","unstructured":"Pourhoseingholi MA, Baghestani AR, Vahedi M. How to control confounding effects by statistical analysis. Gastroenterol Hepatol from bed to bench [Internet]. 2012;5:79\u201383. http:\/\/www.ncbi.nlm.nih.gov\/pubmed\/24834204"},{"key":"3093_CR14","doi-asserted-by":"publisher","first-page":"268","DOI":"10.7326\/M16-2607","volume":"167","author":"TJ VanderWeele","year":"2017","unstructured":"VanderWeele TJ, Ding P. Sensitivity Analysis in Observational Research: Introducing the E-Value. Ann Intern Med [Internet]. 2017;167:268\u201374. https:\/\/doi.org\/10.7326\/M16-2607.","journal-title":"Ann Intern Med [Internet]"},{"key":"3093_CR15","doi-asserted-by":"publisher","first-page":"558","DOI":"10.4097\/kja.19087","volume":"72","author":"JH Kim","year":"2019","unstructured":"Kim JH. Multicollinearity and misleading statistical results. Korean J Anesthesiol [Internet]. 2019;72:558\u201369. https:\/\/doi.org\/10.4097\/kja.19087.","journal-title":"Korean J Anesthesiol [Internet]"},{"key":"3093_CR16","first-page":"627","volume":"4","author":"K Hajian-Tilaki","year":"2013","unstructured":"Hajian-Tilaki K. Receiver Operating Characteristic (ROC) Curve Analysis for Medical Diagnostic Test Evaluation. Casp J Intern Med [Internet]. 2013;4:627\u201335. http:\/\/www.ncbi.nlm.nih.gov\/pubmed\/24009950.","journal-title":"Casp J Intern Med [Internet]"},{"key":"3093_CR17","unstructured":"Brasil M. da S. Resolu\u00e7\u00e3o No 466, de 12 de dezembro de 2012 [Internet]. Di\u00e1rio Of. da Uni\u00e3o DOU. 2012 [cited 2019 Sep 14]. p. 12. https:\/\/conselho.saude.gov.br\/resolucoes\/2012\/Reso466.pdf. Accessed 14 Sep 2019."},{"key":"3093_CR18","doi-asserted-by":"publisher","first-page":"407","DOI":"10.1016\/S2213-2600(20)30560-9","volume":"9","author":"OT Ranzani","year":"2021","unstructured":"Ranzani OT, Bastos LSL, Gelli JGM, Marchesi JF, Bai\u00e3o F, Hamacher S, et al. Characterisation of the first 250 000 hospital admissions for COVID-19 in Brazil: a retrospective analysis of nationwide data. Lancet Respir Med [Internet]. 2021;9:407\u201318. https:\/\/doi.org\/10.1016\/S2213-2600(20)30560-9.","journal-title":"Lancet Respir Med [Internet]"},{"key":"3093_CR19","doi-asserted-by":"publisher","first-page":"e82","DOI":"10.1016\/S2213-2600(21)00287-3","volume":"9","author":"LS Bastos","year":"2021","unstructured":"Bastos LS, Ranzani OT, Souza TML, Hamacher S, Bozza FA. COVID-19 hospital admissions: Brazil\u2019s first and second waves compared. Lancet Respir Med [Internet]. 2021;9:e82\u20133. https:\/\/doi.org\/10.1016\/S2213-2600(21)00287-3.","journal-title":"Lancet Respir Med [Internet]"},{"key":"3093_CR20","doi-asserted-by":"publisher","first-page":"e1018","DOI":"10.1016\/S2214-109X(20)30285-0","volume":"8","author":"P Baqui","year":"2020","unstructured":"Baqui P, Bica I, Marra V, Ercole A, van der Schaar M. Ethnic and regional variations in hospital mortality from COVID-19 in Brazil: a cross-sectional observational study. Lancet Glob Heal [Internet]. 2020;8:e1018\u201326. https:\/\/doi.org\/10.1016\/S2214-109X(20)30285-0.","journal-title":"Lancet Glob Heal [Internet]"},{"key":"3093_CR21","doi-asserted-by":"publisher","first-page":"101323","DOI":"10.1016\/j.lana.2025.101323","volume":"54","author":"PdeM Sato","year":"2026","unstructured":"Sato PdeM, Lopes F, English S, Oliveira da Silva S, Lalane JB, Deivanayagam TA, et al. Mapping the expressions and impacts of racism on health in Brazil: a scoping review. Lancet Reg Heal - Am [Internet]. 2026;54:101323. https:\/\/doi.org\/10.1016\/j.lana.2025.101323.","journal-title":"Lancet Reg Heal - Am [Internet]"},{"key":"3093_CR22","doi-asserted-by":"publisher","first-page":"1573","DOI":"10.1186\/s12913-025-13527-6","volume":"25","author":"R Coelho","year":"2025","unstructured":"Coelho R, Mrejen M, Falc\u00e3o L, Rocha R, Hone T. Racial inequalities in access to healthcare services in Brazil (2019): a decomposition analysis. BMC Health Serv Res [Internet]. 2025;25:1573. https:\/\/doi.org\/10.1186\/s12913-025-13527-6.","journal-title":"BMC Health Serv Res [Internet]"},{"key":"3093_CR23","doi-asserted-by":"publisher","first-page":"236","DOI":"10.1007\/s40615-020-00948-8","volume":"9","author":"S Tan","year":"2022","unstructured":"Tan S, Bin, DeSouza P, Raifman M. Structural Racism and COVID-19 in the USA: a County-Level Empirical Analysis. J racial Ethn Heal disparities [Internet]. 2022;9:236\u201346. https:\/\/doi.org\/10.1007\/s40615-020-00948-8.","journal-title":"J racial Ethn Heal disparities [Internet]"},{"key":"3093_CR24","doi-asserted-by":"publisher","first-page":"826","DOI":"10.2105\/AJPH.2004.060749","volume":"96","author":"AT Geronimus","year":"2006","unstructured":"Geronimus AT, Hicken M, Keene D, Bound J. Weathering and age patterns of allostatic load scores among blacks and whites in the United States. Am J Public Health [Internet]. 2006;96:826\u201333. https:\/\/doi.org\/10.2105\/AJPH.2004.060749.","journal-title":"Am J Public Health [Internet]"},{"key":"3093_CR25","doi-asserted-by":"publisher","first-page":"89","DOI":"10.1016\/S0027-9684(15)30120-6","volume":"104","author":"OK Duru","year":"2012","unstructured":"Duru OK, Harawa NT, Kermah D, Norris KC. Allostatic Load Burden and Racial Disparities in Mortality. J Natl Med Assoc [Internet]. 2012;104:89\u201395. https:\/\/doi.org\/10.1016\/S0027-9684(15)30120-6.","journal-title":"J Natl Med Assoc [Internet]"},{"key":"3093_CR26","doi-asserted-by":"publisher","first-page":"335","DOI":"10.1097\/MLR.0b013e318245a53c","volume":"50","author":"N Sonnenfeld","year":"2012","unstructured":"Sonnenfeld N, Pitts SR, Schappert SM, Decker SL. Emergency Department Volume and Racial and Ethnic Differences in Waiting Times in the United States. Med Care [Internet]. 2012;50:335\u201341. https:\/\/doi.org\/10.1097\/MLR.0b013e318245a53c.","journal-title":"Med Care [Internet]"},{"key":"3093_CR27","doi-asserted-by":"publisher","first-page":"e240046","DOI":"10.1001\/jamahealthforum.2024.0046","volume":"5","author":"AK Agarwal","year":"2024","unstructured":"Agarwal AK, Gonzales RE, Sagan C, Nijim S, Asch DA, Merchant RM, et al. Perspectives of Black Patients on Racism Within Emergency Care. JAMA Heal Forum [Internet]. 2024;5:e240046. https:\/\/doi.org\/10.1001\/jamahealthforum.2024.0046.","journal-title":"JAMA Heal Forum [Internet]"},{"key":"3093_CR28","unstructured":"WHO WHO. Closing the gap in a generation: health equity through action on the social determinants of health - Final report of the commission on social determinants of health [Internet]. WHO. 2008 [cited 2026 Jun 5]. https:\/\/www.who.int\/publications\/i\/item\/WHO-IER-CSDH-08.1?utm_source=chatgpt.com. Accessed 5 Jun 2026."},{"key":"3093_CR29","doi-asserted-by":"crossref","unstructured":"Link BG, Phelan J. Social conditions as fundamental causes of disease. J Health Soc Behav [Internet]. 1995;80\u201394. http:\/\/www.ncbi.nlm.nih.gov\/pubmed\/7560851","DOI":"10.2307\/2626958"},{"key":"3093_CR30","doi-asserted-by":"publisher","first-page":"18472","DOI":"10.1038\/s41598-022-23365-9","volume":"12","author":"DM Sardinha","year":"2022","unstructured":"Sardinha DM, de S\u00e1 CAF, Rodrigues YC, dos Santos Freitas J, Brodeur K, do Socorro Pompeu, de Loiola R, et al. Characteristics and outcomes of severe COVID-19 in hospitalized patients with cardiovascular diseases in the Amazonian region of Brazil: a retrospective cohort. Sci Rep. 2022;12:18472. https:\/\/doi.org\/10.1038\/s41598-022-23365-9.","journal-title":"Sci Rep"},{"key":"3093_CR31","doi-asserted-by":"publisher","first-page":"861","DOI":"10.3390\/vaccines11040861","volume":"11","author":"DM da Sardinha","year":"2023","unstructured":"Sardinha DM, Ferreira AL, da Guimar\u00e3es S, de PS RJ e, Lima KVB, Lima LNGC. Clinical Characteristics and Outcomes among Vaccinated and Unvaccinated Patients with Cardiovascular Disease Who Were Hospitalized for COVID-19 in Brazil: Retrospective Cohort. Vaccines [Internet]. 2023;11:861. . https:\/\/doi.org\/10.3390\/vaccines11040861","journal-title":"Vaccines [Internet]"},{"key":"3093_CR32","doi-asserted-by":"publisher","DOI":"10.1590\/0037-8682-0014-2021","author":"I Silva","year":"2021","unstructured":"Silva I, de Faria NC, Ferreira \u00c1RS, Anast\u00e1cio LR, Ferreira LG. Risk factors for critical illness and death among adult Brazilians with COVID-19. Rev Soc Bras Med Trop [Internet]. 2021. https:\/\/doi.org\/10.1590\/0037-8682-0014-2021. 54.","journal-title":"Rev Soc Bras Med Trop [Internet]"},{"key":"3093_CR33","doi-asserted-by":"publisher","first-page":"e049089","DOI":"10.1136\/bmjopen-2021-049089","volume":"11","author":"MC Castro","year":"2021","unstructured":"Castro MC, Gurzenda S, Mac\u00e1rio EM, Fran\u00e7a GVA. Characteristics, outcomes and risk factors for mortality of 522 167 patients hospitalised with COVID-19 in Brazil: a retrospective cohort study. BMJ Open [Internet]. 2021;11:e049089. https:\/\/doi.org\/10.1136\/bmjopen-2021-049089.","journal-title":"BMJ Open [Internet]"},{"key":"3093_CR34","doi-asserted-by":"publisher","first-page":"429","DOI":"10.1186\/s12879-015-1154-y","volume":"15","author":"C Remschmidt","year":"2015","unstructured":"Remschmidt C, Wichmann O, Harder T. Frequency and impact of confounding by indication and healthy vaccinee bias in observational studies assessing influenza vaccine effectiveness: a systematic review. BMC Infect Dis [Internet]. 2015;15:429. https:\/\/doi.org\/10.1186\/s12879-015-1154-y.","journal-title":"BMC Infect Dis [Internet]"},{"key":"3093_CR35","doi-asserted-by":"publisher","first-page":"337","DOI":"10.1093\/ije\/dyi274","volume":"35","author":"LA Jackson","year":"2006","unstructured":"Jackson LA, Jackson ML, Nelson JC, Neuzil KM, Weiss NS. Evidence of bias in estimates of influenza vaccine effectiveness in seniors. Int J Epidemiol [Internet]. 2006;35:337\u201344. https:\/\/doi.org\/10.1093\/ije\/dyi274.","journal-title":"Int J Epidemiol [Internet]"}],"container-title":["Journal of Racial and Ethnic Health Disparities"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1007\/s40615-026-03093-w.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/article\/10.1007\/s40615-026-03093-w","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1007\/s40615-026-03093-w.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,11]],"date-time":"2026-10-11T16:39:43Z","timestamp":1791736783000},"score":1,"resource":{"primary":{"URL":"https:\/\/link.springer.com\/10.1007\/s40615-026-03093-w"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,10,11]]},"references-count":35,"alternative-id":["3093"],"URL":"https:\/\/doi.org\/10.1007\/s40615-026-03093-w","relation":{},"ISSN":["2197-3792","2196-8837"],"issn-type":[{"value":"2197-3792","type":"print"},{"value":"2196-8837","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,10,11]]},"assertion":[{"value":"26 February 2026","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"18 June 2026","order":2,"name":"revised","label":"Revised","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"20 June 2026","order":3,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"11 October 2026","order":4,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"This study used de-identified, publicly available secondary data. According to the Brazilian National Health Council (Resolution CNS 466\/2012), research involving publicly accessible data that does not allow for the identification of participants is exempt from institutional review board (IRB) approval. All procedures were conducted in accordance with the ethical standards of the 1964 Helsinki Declaration.","order":1,"name":"Ethics","label":"Ethics Approval","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"The authors have no relevant financial or non-financial interests to disclose.","order":2,"name":"Ethics","label":"Competing Interests","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"The authors declare that they have no conflict of interest.","order":3,"name":"Ethics","label":"Conflict of interest","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"Not applicable. This study utilized anonymized secondary data from a national surveillance database; therefore, informed consent was not required.","order":4,"name":"Ethics","label":"Consent to Participate","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"The authors affirm that the manuscript is original and has not been published elsewhere.","order":5,"name":"Ethics","label":"Consent to Publish","group":{"name":"EthicsHeading","label":"Declarations"}}]}}