Testing persuasive messages about booster doses of COVID-19 vaccines on intention to vaccinate in Australian adults: A randomised controlled trial.

INTRODUCTION: Achieving high COVID-19 vaccine booster coverage is an ongoing global challenge. Health authorities need evidence about effective communication interventions to improve acceptance and uptake. This study aimed to test effects of persuasive messages about COVID-19 vaccine booster doses on intention to vaccinate amongst eligible adults in Australia. METHODS: In this online randomised controlled trial, adult participants received one of four intervention messages or a control message. The control message provided information about booster dose eligibility. Intervention messages added to the control message, each using a different persuasive strategy, including: emphasising personal health benefits of booster doses, community health benefits, non-health benefits, and personal agency in choosing vaccination. After the intervention, participants answered items about COVID-19 booster vaccine intention and beliefs. Intervention groups were compared to the control using tests of two proportions; differences of ≥5 percentage points were deemed clinically significant. A sub-group analysis was conducted among hesitant participants. RESULTS: Of the 487 consenting and randomised participants, 442 (90.8%) completed the experiment and were included in the analysis. Participants viewing messages emphasising non-health benefits had the highest intention compared to those who viewed the control message (percentage point diff: 9.0, 95% CI -0.8, 18.8, p = 0.071). Intention was even higher among hesitant individuals in this intervention group compared to the control group (percentage point diff: 15.6, 95% CI -6.0, 37.3, p = 0.150). Conversely, intention was lower among hesitant individuals who viewed messages emphasising personal agency compared to the control group (percentage point diff: -10.8, 95% CI -33.0, 11.4, p = 0.330), although evidence in support of these findings is weak. CONCLUSION: Health authorities should highlight non-health benefits to encourage COVID-19 vaccine booster uptake but use messages emphasising personal agency with caution. These findings can inform communication message development and strategies to improve COVID-19 vaccine booster uptake. Clinical trial registration: Registered with the Australian New Zealand Clinical Trials Registry (ACTRN12622001404718); trial webpage: https://www.anzctr.org.au/ACTRN12622001404718.aspx.

Rhetoric, Persuasion, Compulsion, and the Stubborn Problem of Vaccine Hesitancy.

Despite the impact of vaccination on the control and prevention of many infectious diseases, vaccine opposition and hesitancy remain significant barriers to fully protecting individuals and communities against serious disease. The primary response to the problem of vaccine hesitancy includes persuasion and some degree of compulsion, usually in the form of vaccine mandates. Persuasion, if it can be successfully leveraged to provide sufficient control of disease spread, is the ethically preferred approach. Yet persuasion has proven less than adequate, leading to increasing calls for vaccination mandates and the elimination of nonmedical exemptions to those mandates. Four scholars have recently examined the underlying causes of vaccine hesitancy in the interest of improving rhetoric surrounding vaccination. This article reviews those books and offers suggestions for optimizing the strategy of persuasion in the interest of reducing the need for compulsion.

Are people more or less likely to follow advice that is accompanied by a confidence interval?

Are people more or less likely to follow numerical advice that communicates uncertainty in the form of a confidence interval? Prior research offers competing predictions. Although some research suggests that people are more likely to follow the advice of more confident advisors, other research suggests that people may be more likely to trust advisors who communicate uncertainty. Participants (N = 17,615) in 12 incentivized studies predicted the outcomes of upcoming sporting events, the preferences of other survey responders, or the number of deaths due to COVID-19 by a future date. We then provided participants with an advisor's best guess and manipulated whether or not that best guess was accompanied by a confidence interval. In all but one study, we found that participants were either directionally or significantly more likely to choose the advisor's forecast (over their own) when the advice was accompanied by a confidence interval. These results were consistent across different measures of advice following and did not depend on the width of the confidence interval (75% or 95%), advice quality, or on whether people had information about the advisor's past performance. These results suggest that advisors may be more persuasive if they provide reasonably-sized confidence intervals around their numerical estimates. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The effects of short messages encouraging prevention behaviors early in the COVID-19 pandemic.

Effectively addressing public health crises like the COVID-19 pandemic requires persuading the mass public to change their behavior in significant ways. Many efforts to encourage behavior change-such as public service announcements, social media posts, and billboards-involve short, persuasive appeals, yet the effectiveness of these messages is unclear. Early in the COVID-19 pandemic, we tested whether short messages could increase intentions to comply with public health guidelines. To identify promising messages, we conducted two pretests (n = 1,596) in which participants rated the persuasiveness of 56 unique messages: 31 based on the persuasion and social influence literatures and 25 drawn from a pool of crowdsourced messages generated by online respondents. The four top-rated messages emphasized: (1) civic responsibility to reciprocate the sacrifices of health care workers, (2) caring for the elderly and vulnerable, (3) a specific, sympathetic victim, and (4) limited health care system capacity. We then conducted three well-powered, pre-registered experiments (total n = 3,719) testing whether these four top-rated messages, and a standard public health message based on language from the CDC, increased intentions to comply with public health guidelines, such as masking in public spaces. In Study 1, we found the four messages and the standard public health message significantly outperformed a null control. In Studies 2 and 3, we compared the effects of persuasive messages to the standard public health message, finding that none consistently out-performed the standard message. This is in line with other research showing minimal persuasive effects of short messages after the very early stages of the pandemic. Across our studies, we found that (1) short messages can increase intentions to comply with public health guidelines, but (2) short messages featuring persuasive techniques from the social science literature did not substantially outperform standard public health messages.

Persuasive Design Solutions for a Sustainable Workforce: Review of Persuasive Apps for Real-Time Capability Support for Rural Health Care Professionals.

BACKGROUND: There is a need to further investigate how persuasive design principles can change rural health professionals' behaviors to look after their own health workforce capability. Several theories are used when developing apps to persuade people to change behavior, including the Persuasive System Design Model, consisting of primary task, dialogue, system credibility, and social support categories, and Cialdini's principles of persuasion. These have not been analyzed yet in the field of health workforce capability. OBJECTIVE: This study aims to determine the persuasive design techniques used in capability building-related apps and to provide recommendations for designing a health workforce app to increase their persuasiveness. METHODS: A Python script was used to extract a total of 3060 apps from Google Play. Keywords centered around health workforce capability elements. App inclusion criteria were as follows: been updated since 2019, rated by users on average 4 and above, and more than 100,000 downloads. Next, 2 experts reviewed whether 32 persuasive strategies were used in the selected apps, and these were further analyzed by capability categories: competencies and skills, health and personal qualities, values and attitudes, and work organization. RESULTS: In all, 53 mobile apps were systematically reviewed to identify the persuasive design techniques. The most common were surface credibility (n=48, 90.6%) and liking (n=48), followed by trustworthiness (n=43, 81.1%), reminders (n=38, 71.7%), and suggestion (n=30, 56.6%). The techniques in the social support domain were the least used across the different apps analyzed for health workforce capability, whereas those in the primary task support domain were used most frequently. The recommendations reflect learnings from our analysis. These findings provided insight into mobile app design principles relevant to apps used in improving health workforce capability. CONCLUSIONS: Our review showed that there are many persuasive design techniques that can assist in building health workforce capability. Additionally, several apps are available in the market that can assist in improving health workforce capability. There is, however, a specific lack of digital, real-time support to improve health workforce capability. Social support strategies through using social support persuasive design techniques will need to be integrated more prominently into a health workforce capability app. An app to measure and monitor health workforce capability scores can be used in conjunction with direct real-world person and real-time support to discuss and identify solutions to improve health workforce capability for rural and remote health professionals who are at high risk of burnout or leaving the rural health workforce.

Self-esteem influences the willingness to engage in COVID-19 prevention behavior and persuasion efficacy.

RATIONALE: Behaviors such as hand-washing and vaccination save human lives during the COVID-19 pandemic and beyond. Yet, people differ widely in their willingness to engage in them. This investigation examines whether people's willingness to protect themselves physically from contracting coronavirus depends on their self-esteem. Based on self-verification theory, we propose that people who hold negative self-views are less motivated to protect their health which reduces their willingness to engage in recommended preventive measures such as mask-wearing and social-distancing. OBJECTIVE: We set out to test (i) whether self-esteem predicts people's willingness to engage in COVID-19 prevention behaviors, (ii) whether this relationship is due to variance in motivation to protect one's health (as well as alternative mechanisms), and (iii) whether health messages can more successfully persuade low self-esteem people to follow preventive measures by framing those behaviors around protecting the health of others (vs. oneself). METHODS: Four studies were conducted with U.S. and German residents. In Study 1, we examine the association between self-esteem, willingness to engage in self-protection behavior, health motivation, and several alternative accounts. In Study 2, we manipulate state self-esteem, and in Studies 3 and 4, we vary the target of COVID-19 prevention behaviors (self vs. other). RESULTS: People with chronic or temporarily induced low self-esteem report a lower willingness to engage in COVID-19 prevention behaviors because they lack motivation to protect their health. Varying the protection target of preventive behaviors (self vs. others) interacts with self-esteem: Low self-esteem people are more willing to follow preventive measures (e.g., vaccination) when they are framed as protecting others (vs. oneself). CONCLUSIONS: Self-esteem impacts people's behavior during a global pandemic and needs to be considered when designing health communications. Public health messages can increase compliance among individuals with lower self-esteem by framing prevention behaviors as a way to protect the health of others.

Futile or fertile? The effect of persuasive strategies on citizen engagement in COVID-19 vaccine-related tweets across six national health departments.

National health departments across the globe have utilized persuasive strategies to promote COVID-19 vaccines through Twitter. However, the effectiveness of those strategies is unclear. This study thereby examined how national health departments deployed persuasive strategies to promote citizen engagement in COVID-19 vaccine-related tweets in six countries, including the UK, the US, Germany, Japan, South Korea, and India. Guided by the heuristic-systematic model and the health belief model, we found that national health departments differed significantly in the use of systematic-heuristic cues and health belief constructs in COVID-19 vaccine-related tweets. Generally, the provision of scientific information and appeals to anecdotes and fear positively, while appeals to bandwagon negatively, predicted citizen engagement. Messages about overcoming barriers and promoting vaccine benefits and self-efficacy positively affected engagement. Emphases of COVID-19 threats and cues to vaccinate demonstrated negative impacts. Importantly, health departments across countries often used futile or detrimental strategies in tweets. A locally adapted evidence-based approach for COVID-19 vaccination persuasion was discussed.

Fighting COVID-19 Misinformation through an Online Game Based on the Inoculation Theory: Analyzing the Mediating Effects of Perceived Threat and Persuasion Knowledge.

The COVID-19 pandemic was accompanied by the rapid spread of misinformation through social media platforms. This study attempted to develop an online fake news game based on the inoculation theory, applicable to the pandemic context, and aimed at enhancing misinformation discrimination. It also tested whether perceived threat and persuasion knowledge serve as underlying mechanisms of the effects of the intervention on misinformation discrimination. In Study 1, we used online priming to examine the influence of inoculation on misinformation discrimination. In Study 2, we developed an online fake-news-game-based intervention and attempted to validate its effectiveness through a randomized controlled trial while also exploring the mediating roles of perceived threat and persuasion knowledge. In Study 1, brief inoculation information priming significantly enhanced the ability to recognize misinformation (F(2.502) = 8.321, p < 0.001, ηp2 = 0.032). In Study 2, the five-day game-based intervention significantly enhanced the ability to recognize misinformation (F(2.322) = 3.301, p = 0.038, ηp2 = 0.020). The mediation effect of persuasion knowledge was significant (ß = 0.025, SE = 0.016, 95% CI = [0.034, 0.075]), while that of perceived threat was not significant. Online interventions based on the inoculation theory are effective in enhancing misinformation discrimination, and one of the underlying mechanisms of this effect lies in its promotion of persuasion knowledge.

Assessment of the Effectiveness of Identity-Based Public Health Announcements in Increasing the Likelihood of Complying With COVID-19 Guidelines: Randomized Controlled Cross-sectional Web-Based Study.

BACKGROUND: Public health campaigns aimed at curbing the spread of COVID-19 are important in reducing disease transmission, but traditional information-based campaigns have received unexpectedly extreme backlash. OBJECTIVE: This study aimed to investigate whether customizing of public service announcements (PSAs) providing health guidelines to match individuals' identities increases their compliance. METHODS: We conducted a within- and between-subjects, randomized controlled cross-sectional, web-based study in July 2020. Participants viewed two PSAs: one advocating wearing a mask in public settings and one advocating staying at home. The control PSA only provided information, and the treatment PSAs were designed to appeal to the identities held by individuals; that is, either a Christian identity or an economically motivated identity. Participants were asked about their identity and then provided a control PSA and treatment PSA matching their identity, in random order. The PSAs were of approximately 100 words. RESULTS: We recruited 300 social media users from Amazon Mechanical Turk in accordance with usual protocols to ensure data quality. In total, 8 failed the data quality checks, and the remaining 292 were included in the analysis. In the identity-based PSA, the source of the PSA was changed, and a phrase of approximately 12 words relevant to the individual's identity was inserted. A PSA tailored for Christians, when matched with a Christian identity, increased the likelihood of compliance by 12 percentage points. A PSA that focused on economic values, when shown to individuals who identified as economically motivated, increased the likelihood of compliance by 6 points. CONCLUSIONS: Using social media to deliver COVID-19 public health announcements customized to individuals' identities is a promising measure to increase compliance with public health guidelines. TRIAL REGISTRATION: ISRCTN Registry 22331899; https://www.isrctn.com/ISRCTN22331899.

"I Felt Completely Turned off by the Message": The Effects of Controlling Language, Fear, and Disgust Appeals on Responses to COVID-19 Vaccination Messages.

Psychological reactance theory (PRT) posits that when individuals' perceived freedoms are threatened or restricted, they become aversively aroused and are motivated to reestablish those freedoms, leading to a state of psychological reactance. Applying PRT, this study examined the effects of controlling language, fear, and disgust appeals on responses to COVID-19 vaccination promotion messages. Participants were randomly assigned to one of eight conditions across controlling language (high/low), fear appeals (high/low), and disgust appeals (high/low), wherein they viewed two messages, with responses measured after each message. Results showed persuasion was diminished when the levels of any of these three variables were elevated, as in conditions of either high controlling language, high fear appeals, or high disgust appeals. Relative to low levels of these variables, high levels resulted in greater freedom threat perceptions, reactance, source derogation, and less positive attitudes toward the message. A 2-way interaction between fear and disgust appeals on source derogation and message attitudes in the low controlling language condition was significant-participants reported the least source derogation and most positive attitudes toward the message in response to the low controlling language, low fear, and low disgust appeals.

When do persuasive messages on vaccine safety steer COVID-19 vaccine acceptance and recommendations? Behavioural insights from a randomised controlled experiment in Malaysia.

INTRODUCTION: Vaccine safety is a primary concern among vaccine-hesitant individuals. We examined how seven persuasive messages with different frames, all focusing on vaccine safety, influenced Malaysians to accept the COVID-19 vaccine, and recommend it to individuals with different health and age profiles; that is, healthy adults, the elderly, and people with pre-existing health conditions. METHODS: A randomised controlled experiment was conducted from 29 April to 7 June 2021, which coincided with the early phases of the national vaccination programme when vaccine uptake data were largely unavailable. 5784 Malaysians were randomly allocated into 14 experimental arms and exposed to one or two messages that promoted COVID-19 vaccination. Interventional messages were applied alone or in combination and compared against a control message. Outcome measures were assessed as intent to both take the vaccine and recommend it to healthy adults, the elderly, and people with pre-existing health conditions, before and after message exposure. Changes in intent were modelled and we estimated the average marginal effects based on changes in the predicted probability of responding with a positive intent for each of the four outcomes. RESULTS: We found that persuasive communication via several of the experimented messages improved recommendation intentions to people with pre-existing health conditions, with improvements ranging from 4 to 8 percentage points. In contrast, none of the messages neither significantly improved vaccination intentions, nor recommendations to healthy adults and the elderly. Instead, we found evidence suggestive of backfiring among certain outcomes with messages using negative attribute frames, risky choice frames, and priming descriptive norms. CONCLUSION: Message frames that briefly communicate verbatim facts and stimulate rational thinking regarding vaccine safety may be ineffective at positively influencing vaccine-hesitant individuals. Messages intended to promote recommendations of novel health interventions to people with pre-existing health conditions should incorporate safety dimensions. TRIAL REGISTRATION NUMBER: NCT05244356.

Testing persuasive messaging to encourage COVID-19 risk reduction.

What types of public health messages are effective at changing people's beliefs and intentions to practice social distancing to slow the spread of COVID-19? We conducted two randomized experiments in summer 2020 that assigned respondents to read a public health message and then measured their beliefs and behavioral intentions across a wide variety of outcomes. Using both a convenience sample and a pre-registered replication with a nationally representative sample of Americans, we find that a message that reframes not social distancing as recklessness rather than bravery and a message that highlights the need for everyone to take action to protect one another are the most effective at increasing beliefs and intentions related to social distancing. These results provide an evidentiary basis for building effective public health campaigns to increase social distancing during flu pandemics.

How safe is this trip? Judging personal safety in a pandemic based on information from different sources.

In a preregistered experiment, we presented participants with information about the safety of traveling during a deadly pandemic and during a migration trip using five different sources (a news article, a family member, an official organization, someone with personal experience, and the travel organizer) and four different verbal descriptions of the likelihood of safety (very likely, likely, unlikely, and very unlikely). We found that both for the pandemic and migration contexts, judgments about the likelihood of safely traveling and decisions to travel were most strongly influenced by information from the respective official organizations and that participants also indicated greater willingness to share information from official organizations with others. These results are consistent with the established finding that expert sources are more persuasive. However, we also found that, regardless of source, participants thought that it would be safe to travel even when told that it was unlikely or very unlikely to be safe. Additionally, participants did not discriminate between the grades of likelihood description (such as between likely and very likely or between unlikely and very unlikely), suggesting that in the contexts examined directionality matters much more than attempts to communicate more fine-grained likelihood information with verbal phrases. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Stressing the personal benefits of the covid-19 vaccine might encourage more people to accept it.

The studyFreeman D, Loe BS, Yu LM, et al. Effects of different types of written vaccination information on COVID-19 vaccine hesitancy in the UK (OCEANS-III): a single-blind, parallel-group, randomised controlled trial. Lancet Public Health 2021;6:416-27.To read the full NIHR Alert, go to: https://evidence.nihr.ac.uk/alert/stressing-personal-benefits-of-covid-vaccine-could-reduce-hesitancy.

Persuading US White evangelicals to vaccinate for COVID-19: Testing message effectiveness in fall 2020 and spring 2021.

The development of COVID-19 vaccines was an important breakthrough for ending the pandemic. However, people refusing to get vaccinated diminish the level of community protection afforded to others. In the United States, White evangelicals have proven to be a particularly difficult group to convince to get vaccinated. Here we investigate whether this group can be persuaded to get vaccinated. To do this, we leverage data from two survey experiments, one fielded prior to approval of COVID-19 vaccines (study 1) and one fielded after approval (study 2). In both experiments, respondents were randomly assigned to treatment messages to promote COVID-19 vaccination. In study 1, we find that a message that emphasizes community interest and reciprocity with an invocation of embarrassment for choosing not to vaccinate is the most effective at increasing uptake intentions, while values-consistent messaging appears to be ineffective. In contrast, in study 2 we observe that this message is no longer effective and that most messages produce little change in vaccine intent. This inconsistency may be explained by the characteristics of White evangelicals who remain unvaccinated vis à vis those who got vaccinated. These results demonstrate the importance of retesting messages over time, the apparent limitations of values-targeted messaging, and document the need to consider heterogeneity even within well-defined populations. This work also cautions against drawing broad conclusions from studies carried out at a single point in time during the COVID-19 pandemic.

Co-design of a digital dietary intervention for adults at risk of type 2 diabetes.

BACKGROUND: Co-design has the potential to create interventions that lead to sustainable health behaviour change. Evidence suggests application of co-design in various health domains has been growing; however, few public-facing digital interventions have been co-designed to specifically address the needs of adults at risk of Type 2 diabetes (T2D). This study aims to: (1) co-design, with key stakeholders, a digital dietary intervention to promote health behaviour change among adults at risk of T2D, and (2) evaluate the co-design process involved in developing the intervention prototype. METHODS: The co-design study was based on a partnership between nutrition researchers and designers experienced in co-design for health. Potential end-users (patients and health professionals) were recruited from an earlier stage of the study. Three online workshops were conducted to develop and review prototypes of an app for people at risk of T2D. Themes were inductively defined and aligned with persuasive design (PD) principles used to inform ideal app features and characteristics. RESULTS: Participants were predominantly female (range 58-100%), aged 38 to 63 years (median age = 59 years), consisting of a total of 20 end-users and four experts. Participants expressed the need for information from credible sources and to provide effective strategies to overcome social and environmental influences on eating behaviours. Preferred app features included tailoring to the individual's unique characteristics, ability to track and monitor dietary behaviour, and tools to facilitate controlled social connectivity. Relevant persuasive design principles included social support, reduction (reducing effort needed to reach target behaviour), tunnelling (guiding users through a process that leads to target behaviour), praise, rewards, and self-monitoring. The most preferred prototype was the Choices concept, which focusses on the users' journey of health behaviour change and recognises progress, successes, and failures in a supportive and encouraging manner. The workshops were rated successful, and feedback was positive. CONCLUSIONS: The study's co-design methods were successful in developing a functionally appealing and relevant digital health promotion intervention. Continuous engagement with stakeholders such as designers and end-users is needed to further develop a working prototype for testing.

Messages that increase COVID-19 vaccine acceptance: Evidence from online experiments in six Latin American countries.

As safe and effective vaccines become widely available, attaining herd immunity and limiting the spread of COVID-19 will depend on individuals choosing to vaccinate-and doing so quickly enough to outpace mutations. Using online surveys conducted across six Latin American countries in January 2021, we experimentally assess messages designed to counteract informational deficiencies and collective action problems that may drive hesitancy. We first find that basic vaccine information persuades around 8% of hesitant individuals to become willing to vaccinate, reduces intended wait to vaccinate by 0.4 months, and increases willingness to encourage others to vaccinate. Rather than facilitating free riding, learning, or social conformity, additional information about others' behavior increases vaccine acceptance when respondents expect herd immunity will be achieved. Finally, priming the social approval benefits of vaccinating also increases vaccine acceptance. These results suggest that providing information and shaping social expectations and incentives could both significantly increase vaccine uptake.