Open Access2009–2010 Influenza A(H1N1)-related critical illness among Aboriginal and non-Aboriginal Canadians
Author(s) -
James J. Jung,
Ruxandra Pinto,
Ryan Zarychanski,
Deborah J. Cook,
Philippe Jouvet,
John C. Marshall,
Anand Kumar,
Jennifer Long,
Rachel Rodin,
Robert Fowler
Publication year - 2017
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0184013
Subject(s) - medicine , interquartile range , mechanical ventilation , critical illness , critically ill , cohort , psychological intervention , prospective cohort study , cohort study , demography , pediatrics , psychiatry , sociology
Background Preliminary studies suggested that Aboriginal Canadians had disproportionately higher rates of infection, hospitalization, and critical illness due to pandemic Influenza A(H1N1)pdm09. Methods We used a prospective cohort study of critically ill patients with laboratory confirmed or probable H1N1 infection in Canada between April 16 2009 and April 12 2010. Baseline characteristics, medical interventions, clinical course and outcomes were compared between Aboriginal and non-Aboriginal patients. The primary outcome was hospital mortality. Results Of 647 critically ill adult patients with known ethnicity, 81 (12.5%) were Aboriginal, 566 (87.5%) were non-Aboriginal. Aboriginal patients were younger (mean [SD] age 40.7[13.7] v. 49.0[14.9] years, p < 0.001) and more frequently female (64.2% v. 51.1%, p = 0.027). Rates of any co-morbid illnesses (Aboriginal v. non-Aboriginal, 92.6% v. 91.0%, p = 0.63), time from symptom onset to hospital admission (median [interquartile range] 4 [2–7] v. 4 [2–7] days, p = 0.84), time to ICU admission (5 [3–8] v.5 [3–8] days, p = 0.91), and severity of illness (mean APACHE II score (19.9 [9.6] v. 21.1 [9.9], p = 0.33) were similar. A similar proportion of Aboriginal patients received antiviral medication before ICU admission than non-Aboriginal patients (91.4% v. 93.8%, p = 0.40). Among Aboriginal versus non-Aboriginal patients, the need for mechanical ventilation (93.8% v. 88.6%, p = 0.15), ventilator-free days (14 [3–23] v. 17 [0–24], p = 0.62), durations of stay in ICU (13[7-19.5] v. 11 [5–8] days, p = 0.05), hospital (19 [12.5-33.5] v. 18 [11-35] days, p = 0.63), and hospital mortality were similar (19.8% v. 22.6%, p = 0.56). In multiple logistic regression analyses, higher APACHE II score (1.06; 1.04-1.09, p<0.001) was independently associated with an increased risk of death; antiviral treatment with a lower risk of death (0.34; 0.15 – 0.78, p = 0.01). Ethnicity was not associated with mortality. Interpretation During the 2009-2010 Influenza A (H1N1) pandemic, Aboriginal and non-Aboriginal Canadians with H1N1-related critical illness had a similar risk of death, after adjusting for potential confounding factors.