What predicts postpartum pertussis booster vaccination? A controlled intervention trial.

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). CONCLUSION: 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%.

Midwife attitudes: an important determinant of maternal postpartum pertussis booster vaccination.

BACKGROUND: The study was designed to determine the feasibility of implementing routine dTpa vaccination in the maternity ward to new mothers and to assess midwives' attitudes toward pertussis booster vaccination, their perceived susceptibility and severity of pertussis in their patients' communities, the perceived barriers and benefits of their patients' vaccinations, and their cues to action and self-efficacy in delivering the vaccine. METHOD: A self-completed questionnaire was developed to evaluate constructs of the Health Belief Model as well as to measure midwife demographic information. Questionnaires were completed by midwives during in-services at both a public hospital and a private hospital in New South Wales, Australia. RESULTS: Midwives who perceived ease in integrating booster vaccination into their workload were more likely to have high self-efficacy in delivering booster vaccination, measured through perceived importance of the role as part of their job (r = .449, p<.01), perceived confidence in delivering vaccination as part of their role (r = .608, p<.01), and perceived sufficient level of skills to deliver booster vaccination (r = .528, p<.01). CONCLUSIONS: These results suggest that, of the factors measured, the most important to midwives in terms of providing pertussis booster vaccination to mothers was their own perceived self-efficacy of providing the vaccination. To increase midwives' desire and confidence to provide pertussis booster to mothers, educational materials and skills workshops could be offered.