{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,28]],"date-time":"2026-10-28T06:34:16Z","timestamp":1793169256757,"version":"4.5.0"},"reference-count":27,"publisher":"Oxford University Press (OUP)","issue":"4","funder":[{"DOI":"10.13039\/100000030","name":"Centers for Disease Control and Prevention","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100000030","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2025,10,15]]},"abstract":"<jats:title>Abstract<\/jats:title>\n               <jats:sec>\n                  <jats:title>Background<\/jats:title>\n                  <jats:p>Various underlying medical conditions (UMCs) elevate the risk of influenza-associated hospitalization. We evaluated how these rates changed by type and number of UMCs.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>Retrospective cohorts were constructed among adult members of 2 health systems aged \u226518 years with prior healthcare utilization. Across the 2016\u20132017 to 2019\u20132020 seasons, we estimated influenza-associated hospitalization rates by type and number of UMCs. Hospitalizations were defined using discharge diagnoses or laboratory confirmation. We calculated adjusted rate ratios (aRRs) using Poisson regression controlling for site, season, and demographic characteristics. We used causal mediation to estimate the effect of UMCs on influenza-associated hospitalization accounting for influenza vaccination status.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>Among 870 888 cohort members, 1403 were hospitalized with influenza at least once within a season across 4 seasons. The aRR for influenza-associated hospitalization was highest for individuals with congestive heart failure (4.2 [95% confidence interval, 3.6\u20134.9] compared to those without congestive heart failure). The aRRs also increased with each additional UMC compared to those with no UMCs. The effect of UMCs on influenza-associated hospitalizations was higher when not mediated by vaccination status; for those with \u22654 UMCs compared to no UMCs, rates were about 60% higher.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusions<\/jats:title>\n                  <jats:p>The burden of baseline medical conditions is associated with higher rates of influenza-associated hospitalization. Among those with varying types and number of UMCs, if vaccination prevalence had been lower than observed, influenza-associated hospitalization rates would have been higher. These findings highlight the importance of preventive medical care and annual influenza vaccination in reducing influenza-associated hospitalizations, particularly for individuals at high risk.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1093\/infdis\/jiaf164","type":"journal-article","created":{"date-parts":[[2025,3,31]],"date-time":"2025-03-31T12:54:03Z","timestamp":1743425643000},"page":"e642-e650","source":"Crossref","is-referenced-by-count":3,"title":["Influenza-Associated Hospitalization Rates by Underlying Conditions, 2016\u20132017 to 2019\u20132020: A Retrospective Cohort Study"],"prefix":"10.1093","volume":"232","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6948-3918","authenticated-orcid":false,"given":"Aaron M","family":"Frutos","sequence":"first","affiliation":[{"name":"Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention , Atlanta, Georgia ,","place":["USA"]},{"name":"Epidemic Intelligence Service, Centers for Disease Control and Prevention , Atlanta, Georgia ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8702-8393","authenticated-orcid":false,"given":"Mark W","family":"Tenforde","sequence":"additional","affiliation":[{"name":"Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention , Atlanta, Georgia ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Devi","family":"Sundaresan","sequence":"additional","affiliation":[{"name":"Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention , Atlanta, Georgia ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Allison L","family":"Naleway","sequence":"additional","affiliation":[{"name":"Kaiser Permanente Center for Health Research , Portland, Oregon ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stephanie A","family":"Irving","sequence":"additional","affiliation":[{"name":"Kaiser Permanente Center for Health Research , Portland, Oregon ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Malini B","family":"DeSilva","sequence":"additional","affiliation":[{"name":"HealthPartners Institute , Minneapolis, Minnesota ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anupam B","family":"Kharbanda","sequence":"additional","affiliation":[{"name":"Children\u2019s Minnesota , Minneapolis, Minnesota ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Toan C","family":"Ong","sequence":"additional","affiliation":[{"name":"Department of Biomedical Informatics, University of Colorado Anschutz Medical Campus , Aurora, Colorado ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0334-6301","authenticated-orcid":false,"given":"Suchitra","family":"Rao","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, University of Colorado Anschutz Medical Campus , Aurora, Colorado ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kai","family":"Zheng","sequence":"additional","affiliation":[{"name":"Department of Informatics, University of California, Irvine , Irvine, California ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shruti K","family":"Gohil","sequence":"additional","affiliation":[{"name":"Department of Medicine, University of California, Irvine , Irvine, California ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sarah W","family":"Ball","sequence":"additional","affiliation":[{"name":"Westat , Rockville, Maryland ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rebecca V","family":"Fink","sequence":"additional","affiliation":[{"name":"Westat , Rockville, Maryland ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7944-7638","authenticated-orcid":false,"given":"Carrie","family":"Reed","sequence":"additional","affiliation":[{"name":"Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention , Atlanta, Georgia ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-3493-2989","authenticated-orcid":false,"given":"Shikha","family":"Garg","sequence":"additional","affiliation":[{"name":"Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention , Atlanta, Georgia ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Catherine H","family":"Bozio","sequence":"additional","affiliation":[{"name":"Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention , Atlanta, Georgia ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2025,3,28]]},"reference":[{"key":"2025101515144204900_jiaf164-B1","doi-asserted-by":"crossref","first-page":"f5061","DOI":"10.1136\/bmj.f5061","article-title":"Populations at risk for severe or complicated influenza illness: systematic review and meta-analysis","volume":"347","author":"Mertz","year":"2013","journal-title":"BMJ"},{"key":"2025101515144204900_jiaf164-B2","doi-asserted-by":"crossref","first-page":"ofac131","DOI":"10.1093\/ofid\/ofac131","article-title":"Rates of severe influenza-associated outcomes among older adults living with diabetes\u2014Influenza 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