Effectiveness of Influenza Vaccination on Hospitalizations and Risk Factors for Severe Outcomes in Hospitalized Patients With COPD

• DOI: 10.1016/j.chest.2018.10.044
• Publication Date: 2019-01-04T09:25:51Z
• Authors: Sunita Mulpuru; Li Li; Lingyun Ye; Todd Hatchette; Melissa K. Andrew; Ardith Ambrose; Guy Boivin; William Bowie; Ayman Chit; Gael Dos Santos; May ElSherif; Karen Green; Francois Haguinet; Scott A. Halperin; Barbara Ibarguchi; Jennie Johnstone; Kevin Katz; Joanne M. Langley; Jason LeBlanc; Mark Loeb; Donna MacKinnon-C...; Anne McCarthy; Janet E. McElhaney; Allison McGeer; Jeff Powis; David Richardson; Makeda Semret; Vivek Shinde; Daniel Smyth; Sylvie Trottier; Louis Valiquette; Duncan Webster; Shelly A. McNeil; Philippe Lagace-W...; Bruce Light; Andre Poirier; Stephanie Smith; Gregory Taylor
• Keywords: Adult; Male; Canada; Adolescent; Comorbidity; Middle Aged; Prognosis; Risk Assessment; Severity of Illness Index; 3. Good health; Hospitalization; Pulmonary Disease, Chronic Obstructive; 03 medical and health sciences; 0302 clinical medicine; Influenza A virus; Influenza Vaccines; Risk Factors; Influenza, Human; Humans; Female; Prospective Studies; Aged; Follow-Up Studies

The effectiveness of influenza vaccination in reducing influenza-related hospitalizations among patients with COPD is not well described, and influenza vaccination uptake remains suboptimal.Data were analyzed from a national, prospective, multicenter cohort study including patients with COPD, hospitalized with any acute respiratory illness or exacerbation between 2011 and 2015. All patients underwent nasopharyngeal swab screening with polymerase chain reaction (PCR) testing for influenza. The primary outcome was an influenza-related hospitalization. We identified influenza-positive cases and negative control subjects and used multivariable logistic regression with a standard test-negative design to estimate the vaccine effectiveness for preventing influenza-related hospitalizations.Among 4,755 hospitalized patients with COPD, 4,198 (88.3%) patients with known vaccination status were analyzed. The adjusted analysis showed a 38% reduction in influenza-related hospitalizations in vaccinated vs unvaccinated individuals. Influenza-positive patients (n = 1,833 [38.5%]) experienced higher crude mortality (9.7% vs 7.9%; P = .047) and critical illness (17.2% vs 12.1%; P < .001) compared with influenza-negative patients. Risk factors for mortality in influenza-positive patients included age > 75 years (OR, 3.7 [95% CI, 0.4-30.3]), cardiac comorbidity (OR, 2.0 [95% CI, 1.3-3.2]), residence in long-term care (OR, 2.6 [95% CI, 1.5-4.5]), and home oxygen use (OR, 2.9 [95% CI, 1.6-5.1]).Influenza vaccination significantly reduced influenza-related hospitalization among patients with COPD. Initiatives to increase vaccination uptake and early use of antiviral agents among patients with COPD could reduce influenza-related hospitalization and critical illness and improve health-care costs in this vulnerable population.ClinicalTrials.govNo.:NCT01517191; URL www.clinicaltrials.gov.