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Krystal Lau, Imperial College LondonAbstract: ‘Nudge’-based social norm messages that signal uptake strength of a certain behaviour within a population can be used in public health interventions to shape individuals’ decisions to adopt that behaviour. Messages conveying high influenza vaccination coverage levels signal a strong social norm, encouraging vaccination, but also a low risk of infection, discouraging vaccination and promoting free-riding. The complex interplay between these two signals can result in ambiguous vaccination decision-making behaviour, especially as coverage levels vary. We aimed to measure different vaccination coverage levels’ impact on influenza vaccination intention.

In an online experiment, we randomly assigned 1,365 UK residents aged 18+ years to a control group (with no message) or one of seven treatment groups with different messages of vaccination coverage levels, shown as the proportion of vaccinated people (10%, 25%, 50%, 65%, 75%, 85%, or 95%) in the respondents’ environment. Impact on respondents’ vaccination intention was measured using self-reported intention and three elicited behaviour measures: (a) opening an online map locating nearby private flu jab providers; (b) time looking at this map; and (c) downloading a calendar reminder to vaccinate.

Treatment groups had significantly higher stated and elicited vaccination intention than the control. Below the 75% to 85% threshold, groups treated with higher coverage levels had greater vaccination intention than groups treated with lower levels. Groups treated with coverage levels above this threshold, compared to those below, had lower vaccination intention. Policymakers should consider this curvilinear effect when designing interventions that use social norm messages to ‘nudge’ vaccination.

Biography: Krystal’s research primarily focuses on behavioural economics. Specifically, she investigates the impact of social norms on vaccination decision-making. She also works on identifying and characterizing key players in the anti-vaccination movement on social media. She has a broader interest in infectious diseases and pandemics, transmission of information and beliefs, and social network analysis. Krystal holds an MRes from Imperial College Business School as well as an MSc in Bioscience and Health Policy, a Bachelor's of Science in Biochemistry and Cell Biology, and a Bachelor's of Science in Health Care Management Policy Studies from Rice University in Houston, Texas.

Forthcoming Talks

Avoiding harm from over prescribing conference

Strategies to reduce inappropriate antibiotic use

Monday, 11 November 2019 @ Royal College of Physicians, London

Koen Pouwels, HERC Senior Researcher, will be presenting on 11 November 2019 on this topical subject

Pharmaceutical policies in the long run: Reflections on 60th anniversary of the Hinchliffe Report

Monday, 11 November 2019, 9.15am to 5pm @ Merton College, Merton Street Oxford, OX1 4JD

Organised by the Nuffield Department of Population Health, University of Oxford 11th November 2019 at Merton College, Merton Street Oxford, 9:30 am to 5:00 pm

Sex, risk, and preferences: Using stated preference data to model behaviour in HIV prevention.

Wednesday, 13 November 2019, 12pm to 1pm @ Richard Doll Building, Oxford, OX3 7LF

Antimicrobial resistance summit 2020 london

Rotating interview: crunching the numbers – engaging big business and the public sector

Thursday, 19 March 2020 @ BMA House Conference & Events Venue Tavistock Square, Bloomsbury, London WC1H 9JP, UK - London

Koen Pouwels, HERC Senior Researcher, will be presenting at this conference, organised by The Economist, on 19 March 2020