Vaccination is essential for preventing infectious diseases, yet vaccine hesitancy persists. Healthcare professionals play an important role in forming parental attitudes, and motivational interviewing (MI) has shown promise in addressing hesitancy. This study evaluates the impact of an intervention combining active invitation, MI, and on-site vaccination on vaccination behaviour. In this three-arm randomised controlled trial, parents of 9-year-old children who missed their DT-IPV/MMR vaccination appointment and parents of 10-year-old children who missed their HPV vaccination appointment in March 2023 were assigned to: 1) an intervention group, 2) a flyer group, or 3) a control group. The intervention group received a phone call inviting them to a 30-min face-to-face MI session with a trained professional, aimed at addressing parents' uncertainties and enhancing motivation towards vaccination, with optional on-site vaccination. The flyer group received a simplified, visually enhanced flyer, while the control group received only the standard invitation. All parents were invited to complete a questionnaire. Vaccination intention was measured using a four-point scale, either via images shown during the MI sessions or through a single corresponding question in the online questionnaire. We conducted both univariate and multivariate analyses, using logistic or ordinal regression as appropriate, and adjusted for region, type of vaccination, and parental demographic characteristics, including age, educational level, and country of birth. Both per-protocol (PP) and intention-to-treat (ITT) analyses were performed. A total of 2570 parents were randomised: 873 to the intervention group, 858 to the flyer group, and 839 to the control group. Of 570 parents in the intervention group that were reached by phone, 114 consented to and received the MI session (per-protocol analysis). In the flyer group, 707 parents received a flyer, while 700 parents were reached in the control group. The MI intervention significantly increased both uptake (OR = 3.87; 95% CI: 1.74–8.60) and intention (OR = 3.85; 95% CI: 1.64–9.06) compared to controls. No significant effects were found for the flyer group (vaccine uptake: OR = 1.07; 95% CI: 0.57–2.01, and vaccine intention: OR = 1.26; 95% CI:0.66–2.41). The combination of active invitation, motivational interviewing, and on-site vaccination significantly improved vaccination uptake (OR = 3.87) and intention (OR = 3.85), highlighting the potential of this feasible and scalable approach.
Widdershoven et al. (Fri,) studied this question.