In autumn 2023 the Netherlands changed the appointment system for selected groups eligible for COVID-19 vaccination from a model requiring recipients to self-schedule to a system providing pre-booked appointments. The policy change used a default-setting approach: offering an appointment proactively rather than relying on individuals to arrange one. Default-based interventions can increase uptake for health behaviors, but they can also provoke rebound or negative reactions that undermine their effect. The study reported here used a formative mixed-methods design to explore preferences between appointment types, to measure perceived burden, and to test whether assigning pre-booked appointments affected reported COVID-19 vaccination intentions, including among those expressing hesitancy for that vaccination round.
The study used two complementary phases. Phase 1 involved qualitative interviews to gather in-depth attitudes and reactions to pre-booked appointments. Phase 2 applied an experimental design within a representative online panel to quantify perceived burden and to test effects on vaccination intention. The evaluation targeted three groups who were eligible for pre-booked appointments: people under 60 with an indication for influenza vaccination, adults aged 60–69, and adults aged 70 and older.
Key quantitative elements reported include the sample size for the online panel (n = 1,886) and statistical estimates of perceived burden and intention outcomes for the full sample and for a subgroup reporting hesitancy about that vaccination round. The report presents coefficient estimates for perceived burden and adjusted odds ratios (ORs) for vaccination intentions comparing appointment formats.
Fifteen interviews were conducted to explore how people experienced the change to pre-booked appointments. Interview participants expressed mixed reactions. Some perceived pre-booked appointments as presumptuous or inconvenient, suggesting that receiving a scheduled slot could feel intrusive or misaligned with personal preferences. Others described pre-booked appointments as a helpful aid that supported vaccine uptake by making the process simpler or more salient. Notably, some participants reported both negative and positive sentiments toward pre-booked appointments, indicating that reactions were not uniform and could vary within the same individual depending on context or framing.
In the experimental phase, the representative online panel (n = 1,886) compared perceptions and stated intentions under different appointment conditions. Participants evaluated the perceived burden of arranging vaccination under a self-scheduling model versus receiving a pre-booked appointment. The analysis produced quantitative estimates indicating that participants regarded self-scheduling as less burdensome than pre-booked appointments (Coefficient = -0.23).
The study also tested whether these differences in perceived burden translated into changes in reported vaccination intentions. Adjusted analyses comparing appointment formats found no meaningful increase in vaccination intentions for those offered pre-booked appointments compared with self-scheduling (Adjusted OR = 1.11 in the full sample).
The two-phase evaluation produced a consistent pattern: although participants reported that self-scheduling felt easier and less burdensome, this perception did not result in higher or lower reported COVID-19 vaccination intentions when comparing the two appointment formats. Numerically, the perceived-burden coefficient favored self-scheduling (Coefficient = -0.23), while the adjusted odds ratio for intention in the full sample did not show an increase with pre-booked appointments (Adjusted OR = 1.11).
Qualitative data from interviews contextualized these quantitative findings by showing that pre-booked appointments could be experienced both as an unwelcome imposition and as a helpful nudge, often simultaneously in the same respondents. These mixed attitudes likely explain why a change in default did not produce a clear directional change in stated intention.
The evaluation included a subgroup analysis of participants who reported hesitancy about that vaccination round. In this subgroup, perceived burden differences were similar to the full sample (Coefficient = -0.25, again favoring self-scheduling as less burdensome). However, the adjusted odds ratio for vaccination intention in the hesitant subgroup did not increase with pre-booked appointments (Adjusted OR = 0.88). Thus, among those expressing hesitancy, providing a pre-booked appointment did not raise stated likelihood of vaccination and in adjusted terms was associated with no positive effect on intention.
Taken together, the mixed-methods formative evaluation found that assigning pre-booked appointments elicited both favorable and unfavorable reactions, and that self-scheduling was perceived as easier and more pleasant by participants in a representative panel. Despite differences in perceived burden and mixed sentiments in interviews, the appointment default change did not lead to a measurable change in reported COVID-19 vaccination intentions in either the full sample or the hesitant subgroup.
Given these findings, the authors provided a conservative recommendation: implement pre-booked appointments selectively for older adults who received their COVID-19 vaccination in the previous year. This cautious stance reflects the absence of an observed increase in intentions combined with the mixed qualitative responses to the intervention.
The authors declared that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.