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

Chest. 2019 Jan;155(1):69-78. doi: 10.1016/j.chest.2018.10.044.

Abstract

Background: The effectiveness of influenza vaccination in reducing influenza-related hospitalizations among patients with COPD is not well described, and influenza vaccination uptake remains suboptimal.

Methods: 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.

Results: 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]).

Conclusions: 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.

Trial registry: ClinicalTrials.govNo.:NCT01517191; URL www.clinicaltrials.gov.

Keywords: COPD; hospitalization; influenza; pulmonary; vaccine effectiveness.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Canada / epidemiology
  • Comorbidity
  • Female
  • Follow-Up Studies
  • Hospitalization / trends*
  • Humans
  • Influenza A virus / immunology*
  • Influenza Vaccines / therapeutic use*
  • Influenza, Human / epidemiology
  • Influenza, Human / prevention & control*
  • Male
  • Middle Aged
  • Prognosis
  • Prospective Studies
  • Pulmonary Disease, Chronic Obstructive / epidemiology*
  • Risk Assessment / methods*
  • Risk Factors
  • Severity of Illness Index
  • Survival Rate / trends
  • Vaccination / methods*
  • Young Adult

Substances

  • Influenza Vaccines

Associated data

  • ClinicalTrials.gov/NCT01517191

Grants and funding