Influenza vaccine coverage and factors associated with non-vaccination among adults at high risk for severe outcomes: An analysis of the Canadian Longitudinal Study on Aging

Background Influenza vaccination is recommended in Canada for older adults and those with underlying health conditions due to their increased risk of severe outcomes. Further research is needed to identify who within these groups is not receiving influenza vaccine to identify opportunities to increase coverage. Objectives We aimed to 1) estimate influenza non-vaccination prevalence and 2) assess factors associated with non-vaccination among Canadian adults aged ≥65 and adults aged 46–64 with ≥1 chronic medical condition (CMC) due to their high risk of severe influenza outcomes. Methods We conducted a secondary analysis of cross-sectional data collected from 2015–2018 among participants of the Canadian Longitudinal Study on Aging. For both groups of interest, we estimated non-vaccination prevalence and used logistic regression models to identify factors associated with non-vaccination. We report adjusted odds ratios and 95% confidence intervals for the investigated variables. Results Overall, 29.5% (95% CI: 28.9%, 30.1%) of the 23,226 participants aged ≥65 years and 50.4% (95% CI: 49.4%, 51.3%) of the 11,250 participants aged 46–64 years with ≥1 CMC reported not receiving an influenza vaccination in the past 12 months. For both groups, lack of recent contact with a family doctor and current smoking were independently associated with non-vaccination. Discussion Influenza vaccination helps prevent severe influenza outcomes. Yet, half of adults aged 46–64 years with ≥1 CMC and more than one-quarter of all adults aged ≥65 years did not receive a recommended influenza vaccine in the year prior to the survey. Innovation in vaccination campaigns for routinely recommended vaccines, especially among those without annual family doctor visits, may improve coverage. Conclusion Influenza vaccination coverage among Canadian adults aged 46–64 years with ≥1 CMC and adults aged ≥65 years remains suboptimal. Vaccination campaigns targeting those at high risk of severe outcomes without routine physician engagement should be evaluated to improve uptake.

[1]  C. Bancej,et al.  National Influenza Annual Report, Canada, 2020-2021, in the global context. , 2021, Canada communicable disease report = Releve des maladies transmissibles au Canada.

[2]  Laure Dumolard,et al.  Seasonal influenza vaccination policies in the 194 WHO Member States: The evolution of global influenza pandemic preparedness and the challenge of sustaining equitable vaccine access , 2021, Vaccine: X.

[3]  J. Bresee,et al.  Global burden of influenza-associated lower respiratory tract infections and hospitalizations among adults: A systematic review and meta-analysis , 2021, PLoS medicine.

[4]  M. Haworth-Brockman,et al.  Changes in the incidence of seasonal influenza in response to COVID-19 social distancing measures: an observational study based on Canada’s national influenza surveillance system , 2020, Canadian Journal of Public Health.

[5]  M. Andrew,et al.  Influenza vaccination and the evolution of evidence-based recommendations for older adults: A Canadian perspective. , 2020, Vaccine.

[6]  P. Lopalco,et al.  Does the use of personal electronic health records increase vaccine uptake? A systematic review. , 2020, Vaccine.

[7]  S. C. Oancea,et al.  Does self-rated health status influence receipt of an annual flu vaccination? , 2019, Preventive medicine.

[8]  A. Srivastav,et al.  Seasonal Influenza Vaccination Coverage Trends Among Adult Populations, U.S., 2010-2016. , 2019, American journal of preventive medicine.

[9]  E. R. van den Heuvel,et al.  Cohort Profile: The Canadian Longitudinal Study on Aging (CLSA) , 2019, International journal of epidemiology.

[10]  È. Dubé,et al.  Determinants of non-vaccination against seasonal influenza. , 2018, Health reports.

[11]  J. Lexchin,et al.  A call to mandate patient access to personal primary care medical records across Canada , 2018, Canadian Medical Association Journal.

[12]  È. Dubé,et al.  Determinants of non-vaccination against seasonal influenza in Canadian adults: findings from the 2015–2016 Influenza Immunization Coverage Survey , 2018, Canadian Journal of Public Health.

[13]  Jana Shaw,et al.  Influenza vaccination in the elderly , 2018, Human vaccines & immunotherapeutics.

[14]  C. Hogea,et al.  An analysis of factors associated with influenza, pneumoccocal, Tdap, and herpes zoster vaccine uptake in the US adult population and corresponding inter-state variability , 2017, Human vaccines & immunotherapeutics.

[15]  Jan Kyncl,et al.  Estimates of global seasonal influenza-associated respiratory mortality: a modelling study , 2017, The Lancet.

[16]  A. Casuccio,et al.  Influenza vaccine effectiveness among high-risk groups: A systematic literature review and meta-analysis of case-control and cohort studies , 2017, Human vaccines & immunotherapeutics.

[17]  J. Gardy,et al.  Self-rated health and reasons for non-vaccination against seasonal influenza in Canadian adults with asthma , 2017, PloS one.

[18]  D. Skowronski,et al.  Interim estimates of 2016/17 vaccine effectiveness against influenza A(H3N2), Canada, January 2017 , 2017, Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin.

[19]  M. Russell,et al.  Impact of pharmacist administration of influenza vaccines on uptake in Canada , 2017, Canadian Medical Association Journal.

[20]  P. Raina,et al.  Mining a Unique Canadian Resource: The Canadian Longitudinal Study on Aging , 2015, Canadian Journal on Aging / La Revue canadienne du vieillissement.

[21]  Jeffrey A. Johnson,et al.  Characteristics and health behaviors of diabetic patients receiving influenza vaccination. , 2015, Vaccine.

[22]  J. Buxton,et al.  Influenza immunization in Canada’s low-income population , 2014, BMC Public Health.

[23]  R. Jiménez-García,et al.  Predictors of influenza vaccination in adults with chronic bronchitis. , 2009, Respiratory medicine.

[24]  P. Raina,et al.  The Canadian Longitudinal Study on Aging (CLSA)* , 2009, Canadian Journal on Aging / La Revue canadienne du vieillissement.

[25]  Y. Lau,et al.  Prevalence and correlates of influenza vaccination among non-institutionalized elderly people: An exploratory cross-sectional survey , 2009, International Journal of Nursing Studies.

[26]  A. Cowan,et al.  Influenza vaccine for high-risk non-elderly adults: A national survey of subspecialists , 2008, Human vaccines.

[27]  Yue Chen,et al.  Chronic disease status, self-perceived health and hospital admissions are important predictors for having a flu shot in Canada. , 2007, Vaccine.

[28]  H. Kelly,et al.  Validity of self-reported influenza and pneumococcal vaccination status among a cohort of hospitalized elderly inpatients. , 2007, Vaccine.

[29]  S. Galea,et al.  Distribution of influenza vaccine to high-risk groups. , 2006, Epidemiologic reviews.

[30]  B. Psaty,et al.  Functional status is a confounder of the association of influenza vaccine and risk of all cause mortality in seniors. , 2006, International journal of epidemiology.

[31]  K. Rockwood,et al.  Rates of influenza vaccination in older adults and factors associated with vaccine use: A secondary analysis of the Canadian Study of Health and Aging , 2004, BMC public health.

[32]  M. Fine,et al.  Sensitivity and specificity of patient self-report of influenza and pneumococcal polysaccharide vaccinations among elderly outpatients in diverse patient care strata. , 2003, Vaccine.

[33]  C. Power,et al.  Self-rated health and limiting longstanding illness: inter-relationships with morbidity in early adulthood. , 2001, International journal of epidemiology.

[34]  M. Lougheed,et al.  Influenza vaccination among Canadians with chronic respiratory disease. , 2009, Respiratory medicine.