Trial reportScientific reports2025
Using an inferior decoy alternative to nudge COVID-19 vaccination.
Trial report in Scientific reports, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors.
Funding
Abstract
Optimizing vaccine uptake is a public health challenge that requires the implementation of effective strategies. The asymmetric dominance (or decoy) effect describes the increasing likelihood of selecting an option when a clearly inferior alternative is offered. Therefore, we aimed to test the impact of offering decoy alternatives-less convenient vaccination appointments-on vaccination intentions. Participants aged 18-33 years, residing in England, and initially not intending to get vaccinated, completed three online experiments. Participants were randomly assigned to either a control or an experimental condition in each experiment. The asymmetrically dominated options were: an appointment in two weeks at a distant location (experiment 1); a later time at the participant's local GP, pharmacy, or community centre (experiment 2); and a later time at a distant location (experiment 3). The primary outcome was vaccination intention, while secondary outcomes included an active interest in reading additional information about the vaccination procedure, perceived difficulty and cognitive effort. Initial analysis revealed no evidence of an asymmetric dominance effect. However, further subgroup analysis, supported by formative research, indicated that ensuring decoy alternatives are clearly perceived as inferior could enhance the effectiveness of this approach for certain individuals.
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What Socratic holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.