Developing a practical tool for measuring parental vaccine hesitancy: A people-centered validation approach in Dutch.

Vaccine hesitancy (VH) about routine childhood vaccinations drives falling vaccine uptake rates. This is a major public health challenge and therefore important to monitor uniformly. The challenge is that different methods are used to measure VH and that, in non-English language, there may not be an unequivocal translation of VH terminology. We aimed to develop and validate a method to assess VH in a simple and self-reported manner, with a mixed-methods study using a people-centered approach with a diverse group of parents and illustrated in Dutch. In the quantitative part, parents were asked to rate experienced vaccine hesitancy on a 10-point Likert scale, using five differently worded Dutch translations for VH. We analyzed internal consistency with Cronbach's alpha and correlation with the short parental attitudes about childhood vaccination (PACV-5) scale. A total of 532 parents participated in the survey. We found that the five worded alternatives measured the same construct, indicated by a Cronbach's alpha of 0.95. The wording resembling 'doubt' showed highest correlation with the PACV-5 score (coefficient -0.525, p < .001). In the qualitative part of this study, we conducted cognitive interviews with 12 lower educated parents to evaluate the comprehensibility and interpretation of the question and VH translations. The findings reinforced and added to the quantitative findings that 'doubt' is the preferred wording. Based on the integrated results, we developed the Vaccine Hesitancy Assessment (VHA) tool. We encourage its use for monitoring purposes at the time of decision-making as this may provide a window of opportunity for decision-support interventions.