{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T01:26:34Z","timestamp":1792113994254,"version":"4.4.0"},"reference-count":20,"publisher":"Oxford University Press (OUP)","issue":"4","funder":[{"DOI":"10.13039\/100012665","name":"ICES","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100012665","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100025092","name":"Ontario Ministry of Health","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100025092","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100025090","name":"Ministry of Long-Term Care","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100025090","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Physician Services Inc. Foundation"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2025,4,30]]},"abstract":"<jats:title>Abstract<\/jats:title>\n               <jats:sec>\n                  <jats:title>Background<\/jats:title>\n                  <jats:p>Shorter courses of antibiotic therapy are increasingly recommended to reduce antibiotic exposure. However, quantifying the real-world impact of duration of therapy is hindered by bias common in observational studies. We aimed to evaluate the harms and benefits of longer versus shorter duration of therapy in older adults.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>This was a population-based cohort study using administrative health data from Ontario, Canada. We included outpatients aged 66\u2013110 years who received a prescription for amoxicillin, cephalexin, and\/or ciprofloxacin. Prescriptions were categorized as short (3\u20137 days) or long (8\u201314 days) duration. The primary outcome was a composite of antibiotic-related harms, including adverse reactions, Clostridioides difficile infection, and antibiotic resistance. The secondary outcome was a composite of safety measures including repeat antibiotic prescriptions, hospital visits, and mortality. To reduce risk of bias, we used an instrumental variable analysis where the instrument was prescriber proportion of antibiotics that were long duration.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>Among 117 682 eligible patients, there was no difference in the primary harms outcome for patients receiving longer versus shorter courses of antibiotics (adjusted odds ratio and 95% confidence interval [CI]): amoxicillin, 0.99 (.84\u20131.15); cephalexin, 1.11 (.90\u20131.38); ciprofloxacin, 0.94 (.74\u20131.20). Secondary safety outcomes were similar, with longer compared to shorter courses of antibiotic therapy (odds ratio and 95% CI): amoxicillin, 1.01 (.94\u20131.08); cephalexin, 1.06 (.97\u20131.17); ciprofloxacin, 0.99 (.85\u20131.15).<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusions<\/jats:title>\n                  <jats:p>In this instrumental variable analysis of community-dwelling older adults, longer antibiotic courses were not associated with an increased benefit or harm compared to shorter courses.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1093\/cid\/ciae629","type":"journal-article","created":{"date-parts":[[2024,12,20]],"date-time":"2024-12-20T12:31:59Z","timestamp":1734697919000},"page":"715-722","source":"Crossref","is-referenced-by-count":1,"title":["Evaluating Harms Associated With Prolonged Antibiotic Duration of Therapy in Community-Dwelling Older Adults: A Cohort Study Using Instrumental Variable Analysis"],"prefix":"10.1093","volume":"80","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5467-6776","authenticated-orcid":false,"given":"Bradley J","family":"Langford","sequence":"first","affiliation":[{"name":"Public Health Ontario , Toronto, Ontario ,","place":["Canada"]},{"name":"Dalla Lana School of Public Health, University of Toronto , Toronto, Ontario ,","place":["Canada"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kevin A","family":"Brown","sequence":"additional","affiliation":[{"name":"Public Health Ontario , Toronto, Ontario ,","place":["Canada"]},{"name":"Dalla Lana School of Public Health, University of Toronto , Toronto, Ontario ,","place":["Canada"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cindy","family":"Lau","sequence":"additional","affiliation":[{"name":"ICES , Toronto, Ontario ,","place":["Canada"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrew","family":"Calzavara","sequence":"additional","affiliation":[{"name":"ICES , Toronto, Ontario ,","place":["Canada"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4499-2983","authenticated-orcid":false,"given":"Carsten","family":"Krueger","sequence":"additional","affiliation":[{"name":"Section of Pediatric Infectious Diseases, Department of Pediatrics, Alberta Children\u2019s Hospital , Calgary ,","place":["Canada"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6780-5378","authenticated-orcid":false,"given":"Valerie","family":"Leung","sequence":"additional","affiliation":[{"name":"Public Health Ontario , Toronto, Ontario ,","place":["Canada"]},{"name":"Michael Garron Hospital, Toronto East Health Network"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nick","family":"Daneman","sequence":"additional","affiliation":[{"name":"Public Health Ontario , Toronto, Ontario ,","place":["Canada"]},{"name":"Institute of Health Policy, Management and Evaluation, Sunnybrook Health Sciences , Toronto, Ontario ,","place":["Canada"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kevin L","family":"Schwartz","sequence":"additional","affiliation":[{"name":"Public Health Ontario , Toronto, Ontario ,","place":["Canada"]},{"name":"Dalla Lana School of Public Health, University of Toronto , Toronto, Ontario ,","place":["Canada"]},{"name":"Division of Infectious Diseases, Unity Health Toronto , Toronto, Ontario ,","place":["Canada"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2024,12,30]]},"reference":[{"key":"2025043020395423700_ciae629-B1","doi-asserted-by":"crossref","first-page":"1254","DOI":"10.1001\/jamainternmed.2016.3646","article-title":"The new antibiotic mantra\u2014\u201cshorter is better\u201d","volume":"176","author":"Spellberg","year":"2016","journal-title":"JAMA Intern Med"},{"key":"2025043020395423700_ciae629-B2","doi-asserted-by":"crossref","first-page":"479","DOI":"10.1016\/j.cmi.2021.10.022","article-title":"Estimating daily antibiotic harms: an umbrella review with individual study meta-analysis","volume":"28","author":"Curran","year":"2022","journal-title":"Clin Microbiol Infect"},{"key":"2025043020395423700_ciae629-B3","doi-asserted-by":"crossref","first-page":"261","DOI":"10.1002\/phar.2201","article-title":"Duration of exposure to antipseudomonal \u03b2-lactam antibiotics in the critically ill and 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