Motivational Interview-based Health Mediator Interventions Increase Intent to Vaccinate among Disadvantaged Individuals

"MI use in outreach programs appears to show promise in improving vaccine confidence and intentions among disadvantaged people."

Coverage for recommended COVID-19 and diphtheria-tetanus-poliomyelitis (DTP) booster shots is often inadequate, especially among socially and/or economically disadvantaged populations. Among the factors: Disadvantaged people and migrants may have difficulty accessing clear information and navigating the healthcare system due to low health literacy and language barriers. To overcome these obstacles, outreach programmes have been implemented in various countries, attempting to empower vulnerable and isolated populations and to reduce health inequalities with the help of mobile teams of community health workers or health mediators (HMs). To help HMs in Marseilles, France, deal with vaccine hesitancy (VH) in disadvantaged groups, this group of researchers trained them in motivational interviewing (MI). They then evaluated the effectiveness of this training among HMs on their MI knowledge and skills (objective 1) and among the interviewees on their vaccination readiness (VR) and intention to get vaccinated or accept a booster against COVID-19 and/or DTP (objective 2).

Developed in the 1990s, MI is a collaborative conversational style intended to reinforce a person's own motivation and commitment to behaviour change. MI has been tested in multiple domains related to health behavior change and adapted to vaccination by Gagneur et al., applying the principles of trust, empathic listening, a non-judgmental attitude, understanding, partnership, and respect for autonomy.

For the present study, two MI specialists trained 16 HMs in a 2-day workshop in May 2022 that included a presentation of MI's theoretical foundations and its adaptation to the field of vaccination and that featured role-playing exercises. In addition, HMs attended two 3-hour training sessions conducted by an infectious disease specialist and received a 72-page guide containing vaccination information and a 4-page leaflet summarising the main messages as a reminder during the interviews The trained HMs then put MI into practice during a 3-week field-pilot study in May and attended a second group MI workshop, this time lasting three hours, at the end of the pilot study.

The HMs completed the same MISI (Motivational Interviewing Skills in Immunization) questionnaire just before the training and again at its end. The before/after training comparisons showed a significant increase in MI knowledge (+48%, p = .001), perceived MI skill application (+46%, p = .003), and self-confidence in using MI (+18%, p = .011)/ A significant increase was also observed for the MI skill application score, by 4.5 points after the initial training session.

The actual survey ran from June 8 through July 8 2022. HMs approached people in disadvantaged neighbourhoods of Marseille by street canvassing, going door to door, or visiting health centres, food pantries, local associations, social shelters, etc. They asked people to take part in a survey of their opinions about vaccination. Those who consented completed a questionnaire before and after the interview to measure VR with the 7C scale ("confidence" in health authorities to ensure vaccine safety and efficacy; "complacency", or low perception of risks associated with developing an infectious disease; structural or psychological "constraints" making vaccination difficult or costly; "calculation", or perceived personal benefit/risk balance of vaccines; "collective responsibility", or willingness to protect others acting collectively; "compliance", or support for sanctioning unvaccinated people; and "conspiracy", or believing that vaccines are more dangerous than the diseases they ought to protect from), as well as intentions regarding vaccination/booster against COVID-19 and DTP.

Then the HM conducted a MI-based discussion with each interviewee, following the MI process and techniques covered during the training - namely:

1. Establish, as the initial objective, a trusting relationship by listening carefully and without judgment to individuals' concerns, without trying to correct or counter certain beliefs.
2. Understand the specific reasons for their hesitancy to be able to ascertain what information would improve their perception of vaccination's importance.
3. Deliver this information in collaboration with them and with their consent, to support their personal choice.
4. Respect their personal autonomy while trying to direct the conversation to a more favorable position toward vaccination, as well as promoting partnership and avoiding discord.

HMs enrolled 324 interviewees, 96% of whom completed both questionnaires. (Compared to the French general population, the sample of interviewees included twice as many unemployed people and 5 times as many people born abroad.) VR increased by 6%, and intentions to get vaccinated or update COVID-19 and DTP vaccination increased by 74% and 52%, respectively. Responses to 3 of the 7C items changed after the MI-based intervention: those measuring "confidence" in authorities (+22% agreement, 36% before intervention), "collective responsibility" (+9% agreement, already at 70% before intervention), and "conspiracy" (-26% agreement, 19% before intervention). The lack of effect on the "calculation" and "complacency" dimensions, a phenomenon the researchers explore in the paper, might partly explain the moderate impact on the VR score.

Furthermore, most interviewees were very satisfied with the interview with the HMs, both in terms of content and form (convenient time and place). In particular, the interviewees perceived that the HMs respected their autonomy, an essential MI skill for building trust. However, 21% still had questions about vaccination after the interview.

In conclusion: "training HMs to use MI in outreach programs designed for disadvantaged groups is a promising avenue for addressing their vaccination concerns and probably other topics....[T]o be effective in times of crisis, this type of approach should be well identified in health policy, undertaken by well-identified actors and institutions that receive support (training, resources, sustainability, and recognition) over the long term..."