title: Factors associated with influenza vaccination coverage among the elderly in South Korea: the Fourth Korean National Health and Nutrition Examination Survey (KNHANES IV).
abstract: The annual outbreak of influenza is one of the major causes of morbidity and mortality among the elderly population around the world. While there is an annual vaccine available to prevent or reduce the incidence of disease, not all older people in Korea choose to be vaccinated. There have been few previous studies to examine the factors influencing influenza vaccination in Korea. Thus, this study identifies nationwide factors that affect influenza vaccination rates in elderly Koreans.
  
  
  
  We obtained data from the Fourth Korean National Health and Nutrition Examination Survey 2007-2009 (KNHANES IV), a nationwide health survey in Korea. To assess influenza vaccination status, we analysed answers to a single question from the survey. From the respondents, we selected 3567 elderly population aged 65 years or older, to analyse the effects of variables including sociodemographic, health behavioural risk, health status and psychological factors on vaccination coverage. We identified factors that affect vaccination status using a multiple logistic regression analysis.
  
  
  
  The rate of influenza vaccination in this elderly population was 75.8%. Overall, the most significant determinants for choosing influenza vaccination were a recent history of health screening (adjusted OR (aOR) 2.26, 95% CI 1.92 to 2.66) and smoking (aOR 0.78, 95% CI 0.62 to 0.98). Other contributing factors were age, household income, marital status, alcohol consumption, physical activity level, self-reported health status and a limitation in daily activities. In contrast, psychological factors, including self-perceived quality of life, stress and depressive mood, did not show close association with vaccination coverage.
  
  
  
  To boost influenza vaccination rates in the elderly, an influenza campaign should focus on under-represented groups, especially smokers. Additionally, promoting routine health screening for the elderly may be an efficient way to help achieve higher vaccination rates. Our results highlight the need for a new strategy for the vaccination campaign.
authors.affiliation: Department of Internal Medicine, Seoul National University Hospital, Seoul, South Korea.
authors.forename: David Soonil
authors.initials: DS
authors.lastname: Kwon
authors.affiliation: Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Kyuwoong
authors.initials: K
authors.lastname: Kim
authors.affiliation: Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea.|Department of Family Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Sang Min
authors.initials: SM
authors.lastname: Park
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D006299:Health Services for the Aged; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000517:prevention & control*; D016015:Logistic Models; D008297:Male; D010342:Patient Acceptance of Health Care; D056910:Republic of Korea; D012907:Smoking; D012959:Socioeconomic Factors; D000073887:Vaccination Coverage / Q000706:statistics & numerical data
chemical_list: D007252:Influenza Vaccines
keywords: elderly; factors; influenza; vaccination