Risk factors associated with severe outcomes in adult hospitalized patients according to influenza type and subtype

• Published in: PloS one Vol. 14; no. 1; p. e0210353
• Main Authors: Martínez, Ana, Soldevila, Núria, Romero-Tamarit, Arantxa, Torner, Núria, Godoy, Pere, Rius, Cristina, Jané, Mireia, Domínguez, Àngela
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 11-01-2019; Public Library of Science (PLoS)
• Subjects: Adolescent; Adult; Age; Aged; Aged, 80 and over; Analysis; Biology and life sciences; Chronic obstructive pulmonary diseases; Comorbidity; Critical Care; Death; Demographics; Diagnosis; Epidemiology; Female; Health aspects; Hospital patients; Hospitalization; Humans; Immunization; Immunologic Deficiency Syndromes - epidemiology; Influenza; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H3N2 Subtype; Influenza B virus; Influenza viruses; Influenza, Human - epidemiology; Influenza, Human - mortality; Influenza, Human - virology; Influenzavirus; Logistic Models; Logistic regression; Malalties pulmonars obstructives cròniques; Male; Medicine and Health Sciences; Middle Aged; Mortality; Odds Ratio; Outcome and process assessment (Medical care); Patient outcomes; Patients; People and Places; Regression models; Risk analysis; Risk Factors; Spain - epidemiology; Vaccines; Viruses; Young Adult; Spain; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0210353

Seasonal influenza is a cause of hospitalization, especially in people with underlying disease or extreme age, and its severity may differ depending on the types and subtypes of circulating viruses. We investigated the factors associated with ICU admission or death in hospitalized patients with severe laboratory-confirmed influenza according to the viral type and subtype. An observational epidemiological study was carried out in patients aged ≥18 years from 12 Catalan hospitals between 2010 and 2016. For each reported case we collected demographic, virological and clinical characteristics. A mixed-effects logistic regression model was used to estimate crude and adjusted ORs. 1726 hospitalized patients were included: 595 (34.5%) were admitted to the ICU and 224 (13.0%) died. Lower ICU admission was associated with age ≥75 years in all influenza types and subtypes and with age 65-74 years for type A. In contrast, the 65-74 and ≥75 years age groups were associated with an increased risk of death in all types and subtypes, especially for type B (aOR 27.42, 95% CI: 4.95-151.93 and 15.96; 95% CI: 3.01-84.68). The comorbidity most closely associated with severe outcomes was immune deficiency, which was associated with death for type B (aOR 9.02, 95% CI: 3.05-26.69) and subtype A(H1N1)pdm09 (aOR 3.16, 95% CI: 1.77-5.66). Older age was a differential factor for ICU admission and death: it was associated with lower ICU admission but a risk factor for death. The comorbidity with the closest association with death was immune deficiency, mainly in influenza type B patients.