{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,3]],"date-time":"2026-07-03T01:11:45Z","timestamp":1783041105962,"version":"3.54.6"},"reference-count":35,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2020,1,14]],"date-time":"2020-01-14T00:00:00Z","timestamp":1578960000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004587","name":"Instituto de Salud Carlos III","doi-asserted-by":"publisher","award":["-"],"award-info":[{"award-number":["-"]}],"id":[{"id":"10.13039\/501100004587","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Ag\u00e8ncia de Gesti\u00f3 d\u2019Ajuts Universitaris i de Recerca","award":["2017\/SGR 1342"],"award-info":[{"award-number":["2017\/SGR 1342"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Viruses"],"abstract":"<jats:p>This study investigated the performance of various case definitions and influenza symptoms in a primary healthcare sentinel surveillance system. A retrospective study of the clinical and epidemiological characteristics of the cases reported by a primary healthcare sentinel surveillance network for eleven years in Catalonia was conducted. Crude and adjusted diagnostic odds ratios (aDORs) and 95% confidence intervals (CIs) of the case definitions and symptoms for all weeks and epidemic weeks were estimated. The most predictive case definition for laboratory-confirmed influenza was the World Health Organization (WHO) case definition for ILI in all weeks (aDOR 2.69; 95% CI 2.42\u20132.99) and epidemic weeks (aDOR 2.20; 95% CI 1.90\u20132.54). The symptoms that were significant positive predictors for confirmed influenza were fever, cough, myalgia, headache, malaise, and sudden onset. Fever had the highest aDOR in all weeks (4.03; 95% CI 3.38\u20134.80) and epidemic weeks (2.78; 95% CI 2.21\u20133.50). All of the case definitions assessed performed better in patients with comorbidities than in those without. The performance of symptoms varied by age groups, with fever being of high value in older people, and cough being of high value in children. In patients with comorbidities, the performance of fever was the highest (aDOR 5.45; 95% CI 3.43\u20138.66). No differences in the performance of the case definition or symptoms in influenza cases according to virus type were found.<\/jats:p>","DOI":"10.3390\/v12010095","type":"journal-article","created":{"date-parts":[[2020,1,15]],"date-time":"2020-01-15T10:30:27Z","timestamp":1579084227000},"page":"95","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Usefulness of Clinical Definitions of Influenza for Public Health Surveillance Purposes"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0219-1907","authenticated-orcid":false,"given":"\u00c0ngela","family":"Dom\u00ednguez","sequence":"first","affiliation":[{"name":"Departament de Medicina, Universitat de Barcelona, 08036 Barcelona, Spain"},{"name":"CIBER Epidemiolog\u00eda y Salud P\u00fablica (CIBERESP), 28029 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1353-5325","authenticated-orcid":false,"given":"N\u00faria","family":"Soldevila","sequence":"additional","affiliation":[{"name":"Departament de Medicina, Universitat de Barcelona, 08036 Barcelona, Spain"},{"name":"CIBER Epidemiolog\u00eda y Salud P\u00fablica (CIBERESP), 28029 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0143-5295","authenticated-orcid":false,"given":"N\u00faria","family":"Torner","sequence":"additional","affiliation":[{"name":"Departament de Medicina, Universitat de Barcelona, 08036 Barcelona, Spain"},{"name":"CIBER Epidemiolog\u00eda y Salud P\u00fablica (CIBERESP), 28029 Madrid, Spain"},{"name":"Ag\u00e8ncia de Salut P\u00fablica de Catalunya, Generalitat de Catalunya, 08005 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ana","family":"Mart\u00ednez","sequence":"additional","affiliation":[{"name":"CIBER Epidemiolog\u00eda y Salud P\u00fablica (CIBERESP), 28029 Madrid, Spain"},{"name":"Ag\u00e8ncia de Salut P\u00fablica de Catalunya, Generalitat de Catalunya, 08005 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pere","family":"Godoy","sequence":"additional","affiliation":[{"name":"CIBER Epidemiolog\u00eda y Salud P\u00fablica (CIBERESP), 28029 Madrid, Spain"},{"name":"Ag\u00e8ncia de Salut P\u00fablica de Catalunya, Generalitat de Catalunya, 08005 Barcelona, Spain"},{"name":"Institut de Recerca Biom\u00e8dica de Lleida, Universitat de Lleida, 25198 Lleida, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cristina","family":"Rius","sequence":"additional","affiliation":[{"name":"CIBER Epidemiolog\u00eda y Salud P\u00fablica (CIBERESP), 28029 Madrid, Spain"},{"name":"Ag\u00e8ncia de Salut P\u00fablica de Barcelona, 08023 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1302-6723","authenticated-orcid":false,"given":"Mireia","family":"Jan\u00e9","sequence":"additional","affiliation":[{"name":"CIBER Epidemiolog\u00eda y Salud P\u00fablica (CIBERESP), 28029 Madrid, Spain"},{"name":"Ag\u00e8ncia de Salut P\u00fablica de Catalunya, Generalitat de Catalunya, 08005 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1302-6723","authenticated-orcid":false,"family":"the PIDIRAC Sentinel Surveillance Program of Catalonia","sequence":"additional","affiliation":[{"name":"Departament de Medicina, Universitat de Barcelona, 08036 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,1,14]]},"reference":[{"key":"ref_1","unstructured":"Bennett, J.E., Dolin, R., and Blaser, M.J. 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