title: Cross-sectional and longitudinal factors predicting influenza vaccination in Hong Kong Chinese elderly aged 65 and above.
abstract: OBJECTIVE
  The study investigated cross-sectional predictors of ever-undergone influenza vaccination (IV) and longitudinal predictors of first-time IV among Chinese elderly in Hong Kong.
  
  
  METHODS
  A random telephone survey interviewed 886 Chinese respondents aged 65 and above and 483 of these 886 respondents (54.5%) completed another follow-up questionnaire.
  
  
  RESULTS
  Of the 483 respondents, 25.1% (or 121) had ever undergone IV at baseline; 13% (47 of 362) were vaccinated for the first time during the follow-up period. The cross-sectional data identified 10 significant variables related to the Health Belief Model (HBM) predicting having ever undergone IV (e.g., perceived efficacy of prevention, side effects, financial difficulty, univariate OR=1.58-68.14 and 0.31-0.47). None of these variables could prospectively predict first-time IV during the follow-up period; the only significant variable was whether the respondent visited social centers during the follow-up period (OR=2.74).
  
  
  CONCLUSIONS
  The 10 studied variables (e.g., perceived efficacy, perceived side effects) were predictive of whether ever undergone IV in the cross-sectional survey. These variables were, however, unable to predict first-time IV in the longitudinal study. Therefore, programs modifying these cross-sectional factors (e.g. change perceptions on efficacy and safety) may not be effective in promoting first-time IV among the elderly. Longitudinal intervention studies are warranted.
authors.affiliation: Centre for Epidemiology and Biostatistics, School of Public Health, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong. jlau@cuhk.edu.hk
authors.forename: Joseph T F
authors.initials: JT
authors.lastname: Lau
authors.forename: Jean H
authors.initials: JH
authors.lastname: Kim
authors.forename: Xilin
authors.initials: X
authors.lastname: Yang
authors.forename: Hi Yi
authors.initials: HY
authors.lastname: Tsui
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D003430:Cross-Sectional Studies; D003625:Data Collection; D005260:Female; D015438:Health Behavior; D007722:Health Knowledge, Attitudes, Practice; D006723:Hong Kong; D006801:Humans; D007252:Influenza Vaccines / Q000008:administration & dosage*; D007251:Influenza, Human / Q000453:epidemiology / Q000517:prevention & control; D008137:Longitudinal Studies; D008297:Male; D016017:Odds Ratio; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014611:Vaccination / Q000523:psychology* / Q000706:statistics & numerical data*
chemical_list: D007252:Influenza Vaccines