Promoting Vaccination at Birth Using Motivational Interviewing Techniques Improves Vaccine Intention: The PromoVac Strategy

"...results revealed that the intervention modifies the determinants of vaccination intention."

In countries such as Canada, there are increasing numbers of parents who feel ambivalent toward vaccine effectiveness and safety. Motivational interviewing (MI) is a patient-centred communication style used to enhance patients' internal motivation to change by exploring and resolving their own hesitancy - including perhaps around vaccines. This study assessed the effect of an educational intervention promoting vaccination using MI techniques delivered at the maternity ward to assess mothers' intention to vaccinate their infant at 2 months of age.

MI is based on 4 principles: (i) expressing empathy toward clients, (ii) developing discrepancy between their current and desired behaviours, (iii) dealing with resistance without antagonising, preserving effective communication, and allowing clients to explore their views, and (iv) supporting self-efficacy (confidence in their ability to change).

During a 1-year period, a brief MI session was proposed to mothers who gave birth at Centre hospitalier universitaire de Sherbrooke in Quebec, Canada. The intervention content was adapted from the Health Belief Model (HBM) and the transtheoretical model of behaviour change. Based on this composite model, each mother's intention about vaccination was determined and categorised into one of four states of change adapted to vaccination. This approach aimed to help each woman progress through the later stages of change at her own pace, ultimately enabling her to self-mobilise toward vaccination on her own. The study intervention was administered to mothers 24-48 hours after delivery by one of the three clinical research assistants who had received standardised training on the intervention content and MI approach. The intended duration of the intervention was approximately 20 minutes. At the end of the MI session, a second self-administered questionnaire was administered to mothers. This last questionnaire was collected on discharge from the maternity ward. Multivariate logistic regression was used to identify the determinants of the vaccination intention. Odds ratios (OR) and their respective 95% confidence intervals (CIs) were calculated.

Data were collected from 1,214 and 1,010 questionnaires pre- and post-intervention, respectively. Mothers' intention to vaccinate their infant at 2 months of age was significantly higher - by nearly 15% - after the educational session (87% vs. 72%, p<0.001). The major impact was observed in those mothers who previously declared that they "Probably" intended to vaccinate their child. Prior to the study intervention, this group of mothers represented 24.2% of the total study sample. Following the study intervention, only 11% of mothers declared they "Probably" intended to have their infant vaccinated.

Multivariate analyses revealed that the belief of the importance of starting infant vaccination at 2 months (OR: 7.8 [3.7-16.0]), favourable spousal opinion on vaccination (OR: 4.7 [1.8-12.1]), and risk perception of vaccination (OR: 4.5 [2.6-7.8]) were all positively associated with vaccination intention. As demonstrated in the final multivariate model, the most significant determinants of the intention to vaccinate were not related to knowledge, but to favourable beliefs and attitudes toward vaccination. These results support the claim that new immunisation promotion strategies need to move beyond the "knowledge-deficit model" to improve infant vaccine coverage (VC). Experts suggest that a tailored client-centered approach, based on the respect of client-held values, would be more beneficial to resolving parent ambivalence regarding vaccination than providing information to increase parents' knowledge of vaccination.

Among the 1,010 mothers who completed the post-intervention questionnaire, most declared having appreciated ("Somewhat agree" and "Agree") participating in the intervention and declared they would recommend it to other parents at the maternity ward (>97% for both answers). In addition, 87.1% of respondents felt that the intervention timing was suitable, and 87.5% considered the intervention's duration to be adequate. Finally, 98.7% reported that they felt that the intervention respected their opinion about vaccination.

The researchers reflect on the fact that the communication style utilised in their intervention focused on addressing the mother's concerns regarding the necessity and safety of vaccines rather than on providing information in a directive way. The results show that the MI approach led mothers to resolve their own ambivalence about vaccination and to change their perception about vaccination. Trying to convince parents by providing a lot of information and statistics about vaccination alone can actually compound and increase negative attitudes toward vaccination. Thus, the use of the MI approach may be an effective tool for increasing parents' intention to vaccinate, and to ultimately help curb vaccine hesitancy.