title: What predicts postpartum pertussis booster vaccination? A controlled intervention trial.
abstract: BACKGROUND
  'Cocooning' aims to protect susceptible infants from pertussis via caregiver vaccination. Control trials evaluating educational interventions to promote cocooning are lacking. We evaluated the role of message-framing vs. standard health information in promoting pertussis vaccination.
  
  
  METHODS
  We recruited postpartum women from a maternity hospital in Sydney, Australia (November 2010-July 2012). Participants self-completed a pertussis knowledge and attitudes questionnaire. We then assigned pertussis-susceptible (no pertussis vaccine ≤10 years) participants to receive a gain-framed, loss-framed pamphlet or control (Government Pertussis factsheet) using weekly sequential block allocation. Next, participants were offered a pertussis vaccine (dTpa) and completed a post-questionnaire on discharge.
  
  
  RESULTS
  A baseline questionnaire was completed for 96.4% (1433/1486) of postpartum women approached. Missing data was excluded (n=29). Next, participants (1404) were screened for vaccine status: 324 (23%) reported prior pertussis booster vaccine receipt, leaving 1080 participants requiring vaccination. Among susceptible mothers, 70% (754/1080) were vaccinated post-intervention. Rates were similar between 'gain', 'loss' or 'control' pamphlets (69.1% vs. 71.8% vs. 68.8%; p=0.62). Intention to be vaccinated (OR 2.46, p<0.001; 95% CI: 1.69-3.58), perceived vaccine benefits (OR: 1.61, p<0.001; 95% CI: 1.25-2.15) and having received a vaccine recommendation (OR 1.68; p=0.025; 95% CI: 1.07-2.65) were independent predictors of vaccine uptake. At discharge, overall pertussis vaccine coverage had increased from 23% to 77% among women screened (1078/1404).
  
  
  CONCLUSIONS
  A cocooning strategy for pertussis vaccination can be highly effective when partially implemented within maternity hospitals, with information accompanied by a funded vaccine. Mothers were highly receptive to vaccination in the postnatal ward: facts about pertussis were as effective as message-framing in promoting a high uptake of 70%. Perceived vaccine benefits, intentions and vaccine recommendation were important predictors of uptake. Our intervention trial increased the existing pertussis vaccine coverage of 23-77%.
authors.affiliation: Royal North Shore Hospital, Pacific Highway, St Leonards, NSW 2065, Australia; Discipline of Paediatric and Child Health, University of Sydney, Sydney, Australia; The Children's Hospital at Westmead, Cnr Hawksbury Rd & Hainsworth St, Locked Bag 4001, Westmead, NSW 2145, Australia; National Centre for Immunisation, Research and Surveillance, Sydney, Australia; Kids Research Institute at The Children's Hospital at Westmead, Cnr Hawksbury Rd & Hainsworth St, Locked Bag 4001, Westmead, NSW 2145, Australia. Electronic address: ehay8329@uni.sydney.edu.au.
authors.forename: Elizabeth Helen
authors.initials: EH
authors.lastname: Hayles
authors.affiliation: Discipline of Paediatric and Child Health, University of Sydney, Sydney, Australia; The Children's Hospital at Westmead, Cnr Hawksbury Rd & Hainsworth St, Locked Bag 4001, Westmead, NSW 2145, Australia; Western Sydney Sexual Health Centre, University of Sydney, Jeffery House, Marsden St, Paramatta, NSW, Australia. Electronic address: spring.cooper@sydney.edu.au.
authors.forename: Spring Chenoa
authors.initials: SC
authors.lastname: Cooper
authors.affiliation: Discipline of Paediatric and Child Health, University of Sydney, Sydney, Australia; The Children's Hospital at Westmead, Cnr Hawksbury Rd & Hainsworth St, Locked Bag 4001, Westmead, NSW 2145, Australia; National Centre for Immunisation, Research and Surveillance, Sydney, Australia; Kids Research Institute at The Children's Hospital at Westmead, Cnr Hawksbury Rd & Hainsworth St, Locked Bag 4001, Westmead, NSW 2145, Australia. Electronic address: nicholas.woods@health.nsw.gov.au.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Wood
authors.affiliation: Royal North Shore Hospital, Pacific Highway, St Leonards, NSW 2065, Australia; Discipline of Obstetrics & Gynaecology and Neonatology, University of Sydney, Sydney, Australia; Northern Clinical School at Royal North Shore Hospital, Pacific Highway, St Leonards, NSW 2065, Australia. Electronic address: john.sinn@sydney.edu.au.
authors.forename: John
authors.initials: J
authors.lastname: Sinn
authors.affiliation: Discipline of Paediatric and Child Health, University of Sydney, Sydney, Australia; The Children's Hospital at Westmead, Cnr Hawksbury Rd & Hainsworth St, Locked Bag 4001, Westmead, NSW 2145, Australia. Electronic address: rachel.skinner@health.nsw.gov.au.
authors.forename: S Rachel
authors.initials: SR
authors.lastname: Skinner
mesh_terms: D000328:Adult; D001315:Australia; D005260:Female; D006266:Health Education; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D007117:Immunization, Secondary / Q000706:statistics & numerical data*; D008875:Middle Aged; D010342:Patient Acceptance of Health Care; D049590:Postpartum Period; D011795:Surveys and Questionnaires; D014917:Whooping Cough / Q000276:immunology* / Q000517:prevention & control*; D055815:Young Adult
keywords: Attitudes; Education; Maternal vaccination; Message framing; Pertussis