A megastudy of text-based nudges encouraging patients to get vaccinated at an upcoming doctor's appointment

Strengthening polio vaccine demand in Ghana: Understanding the factors influencing uptake of the vaccine and the effectiveness of different message frames

BACKGROUND

Ghana has experienced recent polio outbreaks. Behavioral insights can be used to understand behavior and create demand for the polio vaccine.

METHODS

This cross-sectional study is based on an interactive mobile phone survey that explored factors influencing the uptake of the polio vaccine among Ghanaian mothers with children younger than five years old. The survey also explores the mothers' intention to vaccinate their children in the future as well as an experiment with short polio vaccine voice message nudges to identify the most effective message frames in encouraging vaccination. The study sample was drawn from volunteers from a mobile service platform. Linear probability model regressions with Ordinary Least Squares (OLS) estimates were used to analyze the data.

RESULTS

In total, data from 708 caregivers was assessed. Out of the sample, 35% (n = 250) had not vaccinated their children against polio, around 8% (n = 53) of respondents stated they did not plan to do so, while 28% expressed intent to do so during the next polio vaccination campaign. Higher vaccination of children against polio, i.e. better uptake of the polio vaccine, appeared to be associated with children's caregivers knowing that polio causes paralysis (with a coefficient of 0.13 (95% CI: 0.02, 0.24), i.e. 13% more likely than not to have their child vaccinated). Higher vaccine uptake also appeared to be associated with the perception that the polio vaccine is safe (with a coefficient of 0.11 (95% CI: 0.01, 0.22), i.e. 11% more likely than not to have their child vaccinated). Another factor in increasing vaccine uptake is whether caregivers receive support from healthcare workers with a coefficient of 0.11 (95% CI: 0.02, 0.20), i.e. 11% more likely than not to have their child vaccinated. Crucially, difficulty accessing the polio vaccine appeared to be associate with a negative change in vaccine uptake (with a coefficient of -0.16 (95% CI: -0.23, -0.08), i.e. 16% less likely to have their child vaccinated). Satisfaction with the information provided by vaccinators was also associated with better vaccine uptake (with a coefficient of 0.12 (95% CI: 0.05, 0.20) i.e. 12% more likely than not to have their child vaccinated); and having seen or heard something negative about the polio vaccine with a coefficient of 0.10 (95% CI: 0.03, 0.17), i.e. 10% more likely than not to have their child vaccinated. The social norms message frame was statistically significant with a coefficient of 0.06 (95% CI: -0.004, 012).

CONCLUSION

The findings from this study suggest that most women with children under the age of 5 appear to have vaccinated their children against polio. Many more caregivers express an intention to vaccinate their children, never having done so before. The behavior and the intention to vaccinate are both driven by a number of factors that must be addressed to create demand for the polio vaccine. Targeted message frames appeared to be statistically significant drivers of vaccine uptake. However, more research is required to understand how they impact vaccine behavior and future intention for vaccination.

Effect of Outreach Messages on Adolescent Well-Child Visits and Coronavirus Disease 2019 Vaccine Rates: A Randomized, Controlled Trial

OBJECTIVE

To determine effectiveness of text/telephone outreach messages, with and without coronavirus disease 2019 (COVID-19) vaccine information.

STUDY DESIGN

We conducted an intent-to-treat, multiarm, randomized clinical trial with adolescents aged 12-17 years. Eligible patients did not have an adolescent well-care visit in the past year or scheduled in the next 45 days or an active electronic health record portal account. We randomized participants to the standard message, COVID-19 vaccine message, or no message (control) group and delivered 2 text messages or telephone calls (per family preference) to the message groups. The primary outcome was adolescent well-care visit completion within 8 weeks, and secondary outcomes were adolescent well-care visit scheduled within 2 weeks and receiving COVID-19 vaccine within 8 weeks.

RESULTS

We randomized 1235 adolescents (mean age, 14 ± 1.5 years; 51.6% male; 76.7% Black; 4.1% Hispanic/Latinx; 88.3% publicly insured). The standard message group had higher odds of scheduling an adolescent well-care visit compared with the control group (OR, 2.07; 95% CI, 1.21-3.52) and COVID-19 vaccine message group (OR, 1.66; 95% CI, 1.00-2.74). The odds of completing an adolescent well-care visit did not differ significantly (standard message group vs control group; OR, 1.35; 95% CI, 0.88-2.06; COVID-19 vaccine message group vs control group, OR, 1.33; 95% CI, 0.87-2.03). In per-protocol analyses, adolescents in the standard message group were twice as likely as the control group to receive the COVID-19 vaccine (OR, 2.48; 95% CI, 1.05-5.86).

CONCLUSIONS

Outreach messages were minimally effective. Efforts are needed to address widening disparities.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT04904744.

Digital public health interventions at scale: The impact of social media advertising on beliefs and outcomes related to COVID vaccines

Public health organizations increasingly use social media advertising campaigns in pursuit of public health goals. In this paper, we evaluate the impact of about $40 million of social media advertisements that were run and experimentally tested on Facebook and Instagram, aimed at increasing COVID-19 vaccination rates in the first year of the vaccine roll-out. The 819 randomized experiments in our sample were run by 174 different public health organizations and collectively reached 2.1 billion individuals in 15 languages. We find that these campaigns are, on average, effective at influencing self-reported beliefs-shifting opinions close to 1% at baseline with a cost per influenced person of about $3.41. Combining this result with an estimate of the relationship between survey outcomes and vaccination rates derived from observational data yields an estimated cost per additional vaccination of about $5.68. There is further evidence that campaigns are especially effective at influencing users' knowledge of how to get vaccines. Our results represent, to the best of our knowledge, the largest set of online public health interventions analyzed to date.

A Comparison of Strategies to Improve Uptake of COVID-19 Vaccine among High-Risk Adults in Nairobi, Kenya in 2022

BACKGROUND

COVID-19 vaccine uptake in Kenya is still low compared to other countries, especially in Europe and North America. In most parts of the country, a large percentage of the Kenyan population remains unvaccinated. As of October 2022, the Ministry of Health (Kenya) estimates that only 36.2% of the adult population had been fully vaccinated.

METHODS

We conducted an experimental study in April 2022 targeting unvaccinated adults who had a history of hypertension and/or diabetes and those in the 60+ age group. We tested various messaging approaches using two different intervention channels.

RESULTS

Although the overall rate of vaccinated individuals according to national records is low, responses from the study group collected through phone call conversations show that higher-risk adults such as those older than 60 or those with chronic illnesses have a remarkably high vaccination rate of 89%. After the study, four participants received a COVID-19 vaccine within 1 month of the intervention. These four participants all received a loss-messaging intervention approach during the study.

CONCLUSION

This study supports a national approach to increasing COVID-19 vaccination rates using loss-messaging directed at unvaccinated, high-risk individuals.

Providing normative information increases intentions to accept a COVID-19 vaccine

Despite the availability of multiple safe vaccines, vaccine hesitancy may present a challenge to successful control of the COVID-19 pandemic. As with many human behaviors, people's vaccine acceptance may be affected by their beliefs about whether others will accept a vaccine (i.e., descriptive norms). However, information about these descriptive norms may have different effects depending on the actual descriptive norm, people's baseline beliefs, and the relative importance of conformity, social learning, and free-riding. Here, using a pre-registered, randomized experiment (N = 484,239) embedded in an international survey (23 countries), we show that accurate information about descriptive norms can increase intentions to accept a vaccine for COVID-19. We find mixed evidence that information on descriptive norms impacts mask wearing intentions and no statistically significant evidence that it impacts intentions to physically distance. The effects on vaccination intentions are largely consistent across the 23 included countries, but are concentrated among people who were otherwise uncertain about accepting a vaccine. Providing normative information in vaccine communications partially corrects individuals' underestimation of how many other people will accept a vaccine. These results suggest that presenting people with information about the widespread and growing acceptance of COVID-19 vaccines helps to increase vaccination intentions.

Effect of Nudges to Clinicians, Patients, or Both to Increase Statin Prescribing: A Cluster Randomized Clinical Trial

Importance

Statins reduce the risk of major adverse cardiovascular events, but less than one-half of individuals in America who meet guideline criteria for a statin are actively prescribed this medication.

Objective

To evaluate whether nudges to clinicians, patients, or both increase initiation of statin prescribing during primary care visits.

Design, Setting, and Participants

This cluster randomized clinical trial evaluated statin prescribing of 158 clinicians from 28 primary care practices including 4131 patients. The design included a 12-month preintervention period and a 6-month intervention period between October 19, 2019, and April 18, 2021.

Interventions

The usual care group received no interventions. The clinician nudge combined an active choice prompt in the electronic health record during the patient visit and monthly feedback on prescribing patterns compared with peers. The patient nudge was an interactive text message delivered 4 days before the visit. The combined nudge included the clinician and patient nudges.

Main Outcomes and Measures

The primary outcome was initiation of a statin prescription during the visit.

Results

The sample comprised 4131 patients with a mean (SD) age of 65.5 (10.5) years; 2120 (51.3%) were male; 1210 (29.3%) were Black, 106 (2.6%) were Hispanic, 2732 (66.1%) were White, and 83 (2.0%) were of other race or ethnicity, and 933 (22.6%) had atherosclerotic cardiovascular disease. In unadjusted analyses during the preintervention period, statins were prescribed to 5.6% of patients (105 of 1876) in the usual care group, 4.8% (97 of 2022) in the patient nudge group, 6.0% (104 of 1723) in the clinician nudge group, and 4.7% (82 of 1752) in the combined group. During the intervention, statins were prescribed to 7.3% of patients (75 of 1032) in the usual care group, 8.5% (100 of 1181) in the patient nudge group, 13.0% (128 of 981) in the clinician nudge arm, and 15.5% (145 of 937) in the combined group. In the main adjusted analyses relative to usual care, the clinician nudge significantly increased statin prescribing alone (5.5 percentage points; 95% CI, 3.4 to 7.8 percentage points; P = .01) and when combined with the patient nudge (7.2 percentage points; 95% CI, 5.1 to 9.1 percentage points; P = .001). The patient nudge alone did not change statin prescribing relative to usual care (0.9 percentage points; 95% CI, -0.8 to 2.5 percentage points; P = .32).

Conclusions and Relevance

Nudges to clinicians with and without a patient nudge significantly increased initiation of a statin prescription during primary care visits. The patient nudge alone was not effective.

Trial Registration

ClinicalTrials.gov Identifier: NCT04307472.

Strategies to increase the intention to get vaccinated against COVID-19: Findings from a nationally representative survey of US adults, October 2020 to October 2021

OBJECTIVES

We examined COVID-19 vaccination status, intention, and hesitancy and the effects of five strategies to increase the willingness of unvaccinated adults (≥18 years) to get a COVID vaccine.

METHODS

Online surveys were conducted between October 1-17, 2020 (N = 14,946), December 4-16, 2020 (N = 15,229), April 8-22, 2021 (N = 14,557), June 17-July 6, 2021 (N = 30,857), and September 3-October 4, 2021 (N = 33,088) with an internet-based, non-probability opt-in sample of U.S. adults matching demographic quotas. Respondents were asked about current COVID-19 vaccination status, intention and hesitancy to get vaccinated, and reasons for vaccine hesitancy. Unvaccinated respondents were assigned to treatment groups to test the effect of five strategies (endorsements, changing social restrictions, financial incentives, vaccine requirements for certain activities, and vaccine requirements for work). Chi-square tests of independence were performed to detect differences in the response distributions.

RESULTS

Willingness to be vaccinated (defined as being vaccinated or planning to be) increased over time from 47.6 % in October 2020 to 81.1 % in October 2021. By October 2021, across most demographic groups, over 75 % of survey respondents had been or planned to be vaccinated. In terms of strategies: (1) endorsements had no positive effect, (2) relaxing the need for masks and social distancing increased Intention to Get Vaccinated (IGV) by 6.4 % (p < 0.01), (3) offering financial incentives increased the IGV between 12.3 and 18.9 % (p <.001), (4) vaccine requirements for attending sporting events or traveling increased IGV by 7.8 % and 9.1 %, respectively (p = 0.02), and vaccine requirement for work increased IGV by 35.4 %. The leading causes (not mutually exclusive) for hesitancy were concerns regarding vaccine safety (52.5 %) or side effects (51.6 %), trust in the government's motives (41.0 %), and concerns about vaccine effectiveness (37.6 %).

CONCLUSIONS

These findings suggest that multiple strategies may be effective and needed to increase COVID-19 vaccination among hesitant adults during the pandemic.

Attitude toward a mandatory COVID-19 vaccination policy and its determinants: Evidence from serial cross-sectional surveys conducted throughout the pandemic in Germany

BACKGROUND

Mandating vaccination against COVID-19 is often discussed as a means to counter low vaccine uptake. Beyond the potential legal, ethical, and psychological concerns, a successful implementation also needs to consider citizens' support for such a policy. Public attitudes toward vaccination mandates and their determinants might differ over time and, hence, should be monitored.

METHODS

Between April 2020 and April 2021, we investigated public support for mandatory vaccination policies in Germany and examined individual correlates, such as vaccination intentions, confidence in vaccine safety, and perceived collective responsibility, using a series of cross-sectional, quota-representative surveys (overall N = 27,509).

RESULTS

Support for a vaccination mandate declined before the approval of the first vaccine against COVID-19 in December 2020 and increased afterwards. However, at the end of April 2021, only half of respondents were in favor of mandatory regulations. In general, mandates were endorsed by those who considered the vaccines to be safe, anticipated practical barriers, and felt responsible for the collective. On the contrary, perceiving vaccination as unnecessary and weighing the benefits and risks of vaccination was related to lower support. Older individuals and males more often endorsed vaccination mandates than did younger participants and females. Interestingly, there was a gap between vaccination intentions and support for mandates, showing that the attitude toward mandatory vaccination was not only determined by vaccination-related factors such as vaccine safety or prosocial considerations.

CONCLUSIONS

Because of low public support, mandatory vaccination against COVID-19 should be considered a measure of last resort in Germany. However, if removing barriers to vaccination and educational campaigns about vaccine safety and the societal benefits of high vaccination uptake are not sufficient for increasing vaccination uptake to the required levels, mandates could be introduced. In this case, measures to ensure and increase acceptance and adherence should be taken.

The association between health information technology and influenza vaccine uptake among adults with heart disease

Aim: Assess the association of health information technology (HIT) on influenza vaccine (IV) uptake among adults with heart disease. Methods: The association of four different uses of HIT - (1) look up health information, (2) schedule medical appointments, (3) refill prescriptions online and (4) communicate with healthcare providers on IV uptake - was analyzed using multiple logistic regression. Results: Adults with heart disease who use the internet to look up information (adjusted odds ratio [AOR] = 1.48, 95% CI: 1.39-1.59; p < 0.001), fill up prescription (AOR = 1.87, 95% CI: 1.69-2.06; p < 0.001), and communicate with a healthcare provider (AOR = 1.95, 95% CI: 1.23-3.10; p = 0.005) had a higher uptake of IV unlike those who did not. Conclusion: Using the internet in patient-healthcare system engagement via HIT was associated with increase IV uptake. Future studies should assess the impact of population-level variables on this relationship.

Can behavior change techniques be delivered via short text messages?

Despite significant advancements in behavioral science it is unclear whether behavior change techniques (or BCTs) can be delivered to large numbers of people in a cost-effective and reliable way. The current study investigated whether it is possible to reliably deliver BCTs using short text messages. Short text messages were designed to deliver each of the 93 BCTs specified in the BCT taxonomy v1. Following initial coding and refinement by the team, a Delphi study with a panel of 15 experts coded which BCT each short text message was designed to deliver and also rated whether they were likely to be understood by recipients and easily converted to target different behaviors. After two iterations, the experts correctly assigned 66 of the 93 messages to the BCT that they were designed to deliver and indicated that these messages were likely to be easy to apply to a range of behaviors and understood by recipients. Experts were not able to identify which BCT 27 of the messages were designed to deliver and it was notable that some clusters of BCTs (e.g., "Goals and planning") were easier to deliver via short text messages than other clusters (e.g., "Scheduled consequences"). The findings suggest that short text messages can be a reliable way to deliver many, but not all, BCTs. The implications of the current study are discussed with respect to the delivery of specific BCTs and clusters of the taxonomy, as well as the need to test the acceptability of interventions delivered via short messages and the impact of messages on behavior.

An Overview of Innovative Approaches to Support Timely and Agile Health Communication Research and Practice

Innovative approaches are needed to make health communication research and practice more timely, responsive, and effective in a rapidly changing information ecosystem. In this paper we provide an overview of strategies that can enhance the delivery and effectiveness of health communication campaigns and interventions, as well as research approaches that can generate useful data and insights for decisionmakers and campaign designers, thereby reducing the research-to-practice gap. The discussion focuses on the following approaches: digital segmentation and microtargeting, social media influencer campaigns, recommender systems, adaptive interventions, A/B testing, efficient message testing protocols, rapid cycle iterative message testing, megastudies, and agent-based modeling. For each method highlighted, we also outline important practical and ethical considerations for utilizing the approach in the context of health communication research and practice, including issues related to transparency, privacy, equity, and potential for harm.

Applications of Behavioral Economics to Pharmaceutical Policymaking: A Scoping Review with Implications for Best-Value Biological Medicines

BACKGROUND AND OBJECTIVE

Pharmaceutical policies are generally based on the assumption that involved stakeholders make rational decisions. However, behavioral economics has taught us that this is not always the case as people deviate from rational behavior in rather predictable patterns. This scoping review examined to what extent behavioral concepts have already been applied in the pharmaceutical domain and what evidence exists about their effectiveness, with the aim of formulating future applications and research hypotheses on policymaking for best-value biologicals.

METHODS

A scoping literature review was conducted on the evidence of behavioral applications to pharmaceuticals. Scientific databases (Embase, MEDLINE, APA PsycArticles, and Scopus) were searched up to 20 October, 2021.

RESULTS

Forty-four full-text scientific articles were identified and narratively described in this article. Pharmaceutical domains where behavioral concepts have been investigated relate to influencing prescribing behavior, improving medication adherence, and increasing vaccination uptake. Multiple behavioral concepts were examined in the identified studies, such as social norms, defaults, framing, loss aversion, availability, and present bias. The effectiveness of the applied interventions was generally positive, but depended on the context. Some of the examined interventions can easily be translated into effective policy interventions for best-value biological medicines. However, some applications require further investigation in a research context.

CONCLUSIONS

Applications of behavioral economics to pharmaceutical policymaking are promising. However, further research is required to investigate the effect of behavioral applications on policy interventions for a more sustainable market environment for best-value biological medicines.

A guide to megastudies

How can behavioral insights best be leveraged to solve pressing policy challenges? Because research studies are typically designed to test the validity of a particular idea, surprisingly little is known about the relative efficacy of different approaches to changing behavior in any given policy context. We discuss megastudies as a research approach that can surmount this and other obstacles to developing optimal behaviorally informed policy interventions. We define a megastudy as "a massive field experiment in which many different treatments are tested synchronously in one large sample using a common, objectively measured outcome." We summarize this apples-to-apples approach to research and lay out recommendations, limitations, and promising future directions for scholars who might want to conduct or evaluate megastudies.

Using nudges to promote clinical decision making of healthcare professionals: A scoping review

Nudging has been discussed in the context of policy and public health, but not so much within healthcare. This scoping review aimed to assess the empirical evidence on how nudging techniques can be used to affect the behavior of healthcare professionals (HCPs) in clinical settings. A systematic database search was conducted for the period January 2010-December 2020 using the PRISMA extension for Scoping Review checklist. Two reviewers independently screened each article for inclusion. Included articles were reviewed to extract key information about each intervention, including purpose, target behavior, measured outcomes, key findings, nudging strategies, intervention objectives and their theoretical underpinnings. Two independent dimensions, building on Kahneman's System 1 and System 2, were used to describe nudging strategies according to user action and timing of their implementation. Of the included 51 articles, 40 reported statistically significant results, six were not significant and two reported mixed results. Thirteen different nudging strategies were identified aimed at modifying four types of HPCs' behavior: prescriptions and orders, procedure, hand hygiene, and vaccination. The most common nudging strategy employed were defaults or pre-orders, followed by alerts or reminders, and active choice. Many interventions did not require any deliberate action from users, here termed passive interventions, such as automatically changing prescriptions to their generic equivalent unless indicated by the user. Passive nudges may be successful in changing the target outcome but may go unnoticed by the user. Future work should consider the broader ethical implications of passive nudges.

Signals of value drive engagement with multi-round information interventions

For information interventions to be effective, recipients must first engage with them. We show that engagement with repeated digital information interventions is shaped by subtle and strategically controllable signals of the information's value. In particular, recipients' expectations are shaped by signals from the "envelope" that surrounds a message in an information intervention. The envelope conveys clues about the message but does not reveal the message itself. When people expect the message to be valuable, delivering it in a consistent and recognizable envelope over time increases engagement relative to varying the envelope. Conversely, when people expect the message to be of little value, delivering it in a consistent and recognizable envelope decreases engagement relative to varying the envelope. We show this with two field experiments involving massive open online courses and one online survey experiment (all pre-registered, N = 439,150).

Can financial incentives and other nudges increase COVID-19 vaccinations among the vaccine hesitant? A randomized trial

Despite rapid initial uptake, COVID-19 vaccinations in the United States stalled within a few months of widespread rollout in 2021. In response, many state and local governments, employers and health systems used public health messaging, financial incentives and creative scheduling tools to increase vaccine uptake. Although these approaches drew on evidence from influenza and other vaccination efforts, they were largely untested in the context of SARS-CoV-2. In mid-2021, months after vaccines were widely available, we evaluated vaccination intentions and vaccine uptake using a randomized control trial. To do this, we recruited unvaccinated members of a Medicaid managed care plan in California (n = 2,701) and randomly assigned them to different public health messages, $10 or $50 financial incentives for vaccination, a simple vaccination appointment scheduler, or control. While messages increased vaccination intentions, none of the interventions increased vaccination rates. Estimates for financial incentives rule out even relatively small increases in vaccination rates. Small financial incentives and other behavioral nudges do not meaningfully increase COVID-19 vaccination rates amongst the vaccine hesitant.

Association between close interpersonal contact and vaccine hesitancy: Findings from a population-based survey in Canada

Background

Vaccine hesitancy threatens efforts to bring the coronavirus disease 2019 (COVID-19) pandemic to an end. Given that social or interpersonal contact is an important driver for COVID-19 transmission, understanding the relationship between contact rates and vaccine hesitancy may help identify appropriate targets for strategic intervention. The purpose of this study was to assess the association between interpersonal contact and COVID-19 vaccine hesitancy among a sample of unvaccinated adults in the Canadian province of British Columbia (BC).

Methods

Unvaccinated individuals participating in the BC COVID-19 Population Mixing Patterns Survey (BC-Mix) were asked to indicate their level of agreement to the statement, "I plan to get the COVID-19 vaccine." Multivariable multinomial logistic regression was used to assess the association between self-reported interpersonal contact and vaccine hesitancy, adjusting for age, sex, ethnicity, educational attainment, occupation, household size and region of residence. All analyses incorporated survey sampling weights based on age, sex, geography, and ethnicity.

Results

Results were based on survey responses collected between March 8, 2021 and December 6, 2021, by a total of 4,515 adults aged 18 years and older. Overall, 56.7% of respondents reported that they were willing to get the COVID-19 vaccine, 27.0% were unwilling and 16.3% were undecided. We found a dose-response association between interpersonal contact and vaccine hesitancy. Compared to individuals in the lowest quartile (least contact), those in the fourth quartile (highest contact), third quartile and second quartile groups were more likely to be vaccine hesitant, with adjusted odd ratios (aORs) of 2.85 (95% CI: 2.02, 4.00), 1.91(95% CI: 1.38, 2.64), 1.78 (95% CI: 1.13, 2.82), respectively.

Conclusion

Study findings show that among unvaccinated people in BC, vaccine hesitancy is greater among those who have high contact rates, and hence potentially at higher risk of acquiring and transmitting infection. This may also impact future uptake of booster doses.

Healthcare workers' acceptability of influenza vaccination nudges: Evaluation of a real-world intervention

Nudges have been proposed as an effective tool to stimulate influenza vaccination uptake in healthcare workers. However, the success of such nudges in practice is heavily reliant on their acceptance by the intended healthcare worker population, which has not been thoroughly examined to date. This study investigated healthcare workers’ acceptability of diverse influenza vaccination nudges implemented in a real-world vaccination campaign and explored the relationship between nudge acceptability and vaccination uptake. A cross-sectional study was conducted among 244 Dutch hospital employees, following a hospital-wide influenza vaccination nudging intervention. A survey assessed healthcare workers’ perceived acceptability of ten distinct influenza vaccination nudges, along with their vaccination status and relevant covariates (e.g., general perceptions regarding influenza vaccination of healthcare workers). Influenza vaccination nudges in general were deemed acceptable, with reward-based nudges being the least accepted, while digital vaccination forms, a mobile vaccination post, peer vaccination, and digital vaccination reminders were most appreciated. A higher overall acceptance of these nudges was associated with a greater likelihood of being vaccinated, particularly in healthcare workers with favorable perceptions of influenza vaccination usefulness. Our findings suggest that influenza vaccination nudges are an accepted means to systematically promote immunization of healthcare workers, and thus present a viable strategy for public health policies aimed at this group.

Meta-nudging honesty: Past, present, and future of the research frontier

Achieving successful and long-lasting behavior change via nudging comes with challenges. This is particularly true when choice architects attempt to change behavior that is collectively harmful but individually beneficial, such as dishonesty. Here, we introduce the concept of "meta-nudging" and illustrate its potential benefits in the context of promoting honesty. The meta-nudging approach implies that instead of nudging end-users directly, one would nudge them indirectly via "social influencers." That is, one can arguably achieve better success by changing the behavior of those who have the ability to enforce other's behavior and norm adherence. We argue that this represents a promising new behavior change approach that helps overcome some of the challenges that the classical nudging approach has faced. We use the case of nudging honesty to develop the theoretical foundation of meta-nudging and discuss avenues for future work.

A novel household-based patient outreach pilot program to boost late-season influenza vaccination rates during the COVID-19 pandemic

Background

The objective of this study was to test a novel household‐based approach to improve late‐season influenza vaccine uptake during the 2020–2021 season, using Epic's MyChart patient portal messages and/or interactive voice response telephone calls.

Methods

This study was a non‐blinded, quality improvement program using a block randomized design conducted among patients from Reliant Medical Group clinics residing in a traditional household (≥2 individuals clinically active in the Reliant system living at the same address). Households were randomized 1:1:1 into intervention arms: non‐tailored communication (messaging based on CDC's seasonal influenza vaccination campaign), tailored communication (comprehensive communication including reinforcement of the importance of influenza vaccination for high‐risk individuals), and standard‐of‐care control. Influenza vaccination during the program was captured via medical records, and the odds of vaccination among communication arms versus the control arm were assessed. A survey assessing influenza vaccination drivers was administered using MyChart.

Results

Influenza vaccination increased by 3.3% during the program period, and no significant differences in vaccination were observed in intervention arms relative to the control arm. Study operationalization faced substantial challenges related to the concurrent COVID‐19 pandemic. Compared with vaccinated survey respondents, unvaccinated respondents less frequently reported receiving a recommendation for influenza vaccination from their healthcare provider (15.8% vs. 42.3%, p < 0.001) or awareness that vaccination could protect themselves and higher risk contacts (82.3% vs. 92.6%, p < 0.001).

Conclusions

No significant effects of the interventions were observed. Survey results highlighted the importance of healthcare provider recommendations and the need for increased education around the benefits of vaccination.

Technology-assisted adaptive recruitment strategy for a large nation-wide COVID-19 vaccine immunogenicity study in Brunei

A national study was conducted in Brunei to assess and compare the immunogenicity of the various brands of COVID-19 vaccines administered to the population as part of the National COVID-19 Vaccination Programme. Most of the population have had received at least 2 doses of BBIBP-CorV, AZD1222 or MRNA-1273 vaccines. Neutralising antibodies against SARS-CoV-2 induced by these vaccines will be analysed to infer population-level immune protection against COVID-19. During the 5-week recruitment period, 24,260 eligible individuals were invited to the study via SMS, out of which 2,712 participants were enrolled into the study. This paper describes the novel adaptive strategy used to recruit the study participants. Digital technology was leveraged to perform targeted online recruitment to circumvent the limitations of traditional recruitment methods. Technology also enabled stratified random selection of these eligible individuals who were stratified based on age, gender and vaccine brand. Data was extracted from the electronic health records, the national mobile health application and a third-party survey platform and integrated into a dedicated research platform called EVYDResearch. The instant availability and access to up-to-date data on EVYDResearch enabled the study team to meet weekly and adopt an adaptive recruitment strategy informed by behavioural science, where interventions could be quickly implemented to improve response rates. Some examples of these include incorporating nudge messaging into SMS invitations, involving the Minister of Health to make press announcements on this study, media coverage, setting up an enquiries hotline and reaching out to foreign language speaking expatriates of a local multinational company to participate in this study. Data integration from various data sources, real time information sharing and a strong teamwork led to good outcomes adaptable to the progress of recruitment, compared to the more time-consuming and static traditional recruitment methods.

Prosocial nudges and visual indicators increase social distancing, but authoritative nudges do not

Social distancing reduces the transmission of COVID-19 and other airborne diseases. To test different ways to increase social distancing, we conducted a field experiment at a major US airport using a system that presented color-coded visual indicators on crowdedness. We complemented those visual indicators with nudges commonly used to increase COVID-19-preventive behaviors. Analyzing data from 57,146 travelers, we find that visual indicators and nudges significantly affected social distancing. Introducing visual indicators increased the share of travelers practicing social distancing, and this positive effect was enhanced by introducing nudges focused on personal benefits ("protect yourself") and public benefits ("protect others"). Conversely, an authoritative nudge referencing the Centers for Disease Control and Prevention ("don't break CDC COVID-19 guidelines") did not change social distancing behavior. Our results demonstrate that visual indicators and informed nudges can boost social distancing and potentially curb the spread of contagious diseases.

Effects of side-effect risk framing strategies on COVID-19 vaccine intentions: a randomized controlled trial

Background:

Fear over side-effects is one of the main drivers of COVID-19 vaccine hesitancy. A large literature in the behavioral and communication sciences finds that how risks are framed and presented to individuals affects their judgments of its severity. However, it remains unknown whether such framing changes can affect COVID-19 vaccine behavior and be deployed as policy solutions to reduce hesitancy.

Methods:

We conducted a pre-registered randomized controlled trial among 8998 participants in the United States and the United Kingdom to examine the effects of different ways of framing and presenting vaccine side-effects on individuals’ willingness to get vaccinated and their perceptions of vaccine safety.

Results:

Adding a descriptive risk label (‘very low risk’) next to the numerical side-effect and providing a comparison to motor-vehicle mortality increased participants’ willingness to take the COVID-19 vaccine by 3.0 percentage points (p=0.003) and 2.4 percentage points (p=0.049), respectively. These effects were independent and additive and combining both framing strategies increased willingness to receive the vaccine by 6.1 percentage points (p<0.001). Mechanistically, we find evidence that these framing effects operate by increasing individuals’ perceptions of how safe the vaccine is.

Conclusions:

Low-cost side-effect framing strategies can meaningfully affect vaccine intentions at a population level.

Funding:

Heidelberg Institute of Global Health.

Clinical trial number:

German Clinical Trials Registry (#DRKS00025551).

Vaccination is one of the main strategies for controlling the COVID-19 pandemic. But vaccination rates have slowed and are below target levels in countries like the United States and the United Kingdom. While there are many causes of vaccine hesitancy, several studies have found that fear of side effects is the one of the most important.

Although COVID-19 vaccine side-effects are rare, how the media presents these risks may amplify concerns. Addressing public concerns over vaccine side effects is key to improving the uptake of vaccines and booster doses, which has been even lower than primary vaccine series uptake.

Studies show that how risk is presented affects people’s risk perceptions and behavior. To learn more about how COVID-19 vaccine risk framing affects risk perception, Sudharsanan et al. enrolled 8,998 people from the United States and the United Kingdom in an online randomized controlled trial. Participants received information about a hypothetical new COVID-19 vaccine, including its side effect rate, and reported their perception of safety and whether they would take the vaccine.

The experiments showed that adding the label “very low risk” when describing vaccine side effect rates increased the number of people who said they would take the vaccine by three percentage points. Comparing the risks of the hypothetical vaccine to the much higher chances of motor vehicle deaths increased an individual’s willingness to take the vaccine by 2.4 percentage points. Combining both framing strategies increased people’s desire to get vaccinated by 6.1 percentage points.

Deploying these two strategies in vaccine risk communications may help increase primary and booster vaccinations against COVID-19. A next step would be to measure both vaccination intentions and vaccination rates to confirm these strategies.

An (un)healthy social dilemma: a normative messaging field experiment with flu vaccinations

BACKGROUND

Influenza seasons can be unpredictable and have the potential to rapidly affect populations, especially in crowded areas. Prior research suggests that normative messaging can be used to increase voluntary provision of public goods, such as the influenza vaccine. We extend the literature by examining the influence of normative messaging on the decision to get vaccinated against influenza.

METHODS

We conduct a field experiment in conjunction with University Health Services, targeting undergraduate students living on campus. We use four posters, randomized by living area clusters to advertise flu vaccination clinics during the Fall. The wording on the posters is varied to emphasize the individual benefits of the vaccine, the social benefits of the vaccine or both benefits together. We collect survey data for those vaccinated at the vaccination clinics, and for those not vaccinated via an online survey.

RESULTS

We find that any normative message increases the percentage of students getting the flu vaccine compared with no message. In terms of the likelihood of getting the flu vaccine, emphasizing both the individual and social benefits of vaccination has the largest increase in the vaccination rate (19-20 percentage point increase). However, flu vaccinations did not reach the herd immunity threshold (70% of students vaccinated).

CONCLUSIONS

This study provides evidence that there is a pro-social component that is relevant in individual vaccination decisions which should be accounted for when designing vaccination campaigns. The results of this normative, pro-social messaging experiment could be extended to other at-risk communities where the number of background risks is much larger. This is especially relevant nowadays, as other seasonal vaccines are being rolled out and younger adults are the ones with the lowest uptake.

Vaccination nudges: A study of pre-booked COVID-19 vaccinations in Sweden

A nudge changes people's actions without removing their options or altering their incentives. During the COVID-19 vaccine rollout, the Swedish Region of Uppsala sent letters with pre-booked appointments to inhabitants aged 16–17 instead of opening up manual appointment booking. Using regional and municipal vaccination data, we document a higher vaccine uptake among 16- to 17-year-olds in Uppsala compared to untreated control regions (constructed using the synthetic control method as well as neighboring municipalities). The results highlight pre-booked appointments as a strategy for increasing vaccination rates in populations with low perceived risk.

Effect of Text Message Reminders and Vaccine Reservations on Adherence to a Health System COVID-19 Vaccination Policy: A Randomized Clinical Trial

IMPORTANCE

Many organizations implemented COVID-19 vaccination requirements during the pandemic, but the best way to increase adherence to these policies is unknown.

OBJECTIVE

To evaluate if behavioral nudges delivered through text messages could accelerate adherence to a health system's COVID-19 vaccination policy.

DESIGN, SETTING, AND PARTICIPANTS

This randomized clinical trial was conducted within Ascension health system from October 11 to November 8, 2021. Participants included health system employees in the Midwest or South US who were not adherent with the vaccination policy 1 month before its deadline. Data were analyzed from November 17, 2021, to February 25, 2022.

INTERVENTIONS

Participants were randomly assigned to control or to receive a text message intervention that stated a vaccine had been reserved for the participant, with a scheduled date for vaccination within a 2-week period. Participants could reschedule to a different date within the period or upload a copy of their vaccination card. Follow-up text message reminders were sent the day before and the day of the appointment.

MAIN OUTCOMES AND MEASURES

The primary outcome was adherence to the health system's vaccination policy during the 2-week intervention. Secondary outcomes included time to vaccination during a 4-week follow-up period.

RESULTS

The sample included 2000 participants (mean [SD] age, 36.4 [12.3] years; 1724 [86.2%] women), with 1000 participants randomized to the control group and 1000 participants randomized to the intervention group. Overall, there were 164 Hispanic participants (8.2%), 46 non-Hispanic Asian participants (2.3%), 202 non-Hispanic Black participants (10.1%), and 1418 non-Hispanic White participants (70.9%). By the end of the 2-week intervention, 363 participants in the text message nudge group (36.3%) and 318 participants in the control group (31.8%) were adherent with the vaccination policy, representing a significant increase of 4.9 (95% CI, 0.8 to 9.1) percentage points in adjusted analyses comparing the nudge group with the control group (P = .02). Among participants who became adherent by the end of the 4-week follow-up period, the text message nudge significantly reduced time to adherence by a mean of 2.4 (95% CI, 2.1 to 4.7) days (P < .001) and a median of 5.0 (95% CI, 2.5 to 7.7) days (P < .001) compared with the control group. At 4 weeks, overall vaccination adherence was no longer different between groups (control: 477 participants [47.7%]; intervention: 472 participants [47.2%]).

CONCLUSIONS AND RELEVANCE

This randomized clinical trial found that a behavioral nudge delivered through text messages accelerated adherence to a health system's COVID-19 vaccination policy but did change overall adherence by the time of the policy deadline.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05037201.

Nudging COVID-19 Vaccine Uptake by Changing the Default: A Randomized Controlled Trial

BACKGROUND

Although vaccination against SARS-CoV-2 is considered the central strategy against the pandemic, uptake lags behind target rates.

METHOD

To explore whether this rate could be enhanced by a nudging strategy that exploits the status quo bias, we conducted a randomized controlled trial in northern Italy comparing vaccination acceptance among 2000 adults, ages 50 to 59 years, who were either invited to set an appointment (opt-in group) or assigned an individual appointment (opt-out group).

RESULTS

Results indicate a difference of 3.2 percentage points, which represents a 32% relative increase in the vaccination rate for the opt-out group compared with the opt-in group.

CONCLUSIONS

A significant portion of those who remain unvaccinated may not hold strong beliefs against vaccination but rather tend to inaction and may therefore be nudged toward vaccination with a reduction of action required.

HIGHLIGHTS

Reluctant adults (50-59 years), who had not yet received vaccines against COVID-19, were sent letters announcing appointment availabilityIn an RCT, the status quo option in the notices influenced the rate of vaccine acceptanceNudging via pre-scheduled appointments encouraged vaccine uptake more than invitations to schedule didSwitching the default option yielded a 32% relative increase (13.1% vs. 9.9%) in vaccination.

Communicating doctors' consensus persistently increases COVID-19 vaccinations

The reluctance of people to get vaccinated represents a fundamental challenge to containing the spread of deadly infectious diseases1,2, including COVID-19. Identifying misperceptions that can fuel vaccine hesitancy and creating effective communication strategies to overcome them are a global public health priority3-5. Medical doctors are a trusted source of advice about vaccinations6, but media reports may create an inaccurate impression that vaccine controversy is prevalent among doctors, even when a broad consensus exists7,8. Here we show that public misperceptions about the views of doctors on the COVID-19 vaccines are widespread, and correcting them increases vaccine uptake. We implement a survey among 9,650 doctors in the Czech Republic and find that 90% of doctors trust the vaccines. Next, we show that 90% of respondents in a nationally representative sample (n = 2,101) underestimate doctors' trust; the most common belief is that only 50% of doctors trust the vaccines. Finally, we integrate randomized provision of information about the true views held by doctors into a longitudinal data collection that regularly monitors vaccination status over 9 months. The treatment recalibrates beliefs and leads to a persistent increase in vaccine uptake. The approach demonstrated in this paper shows how the engagement of professional medical associations, with their unparalleled capacity to elicit individual views of doctors on a large scale, can help to create a cheap, scalable intervention that has lasting positive impacts on health behaviour.

Effect of Text Messaging and Behavioral Interventions on COVID-19 Vaccination Uptake: A Randomized Clinical Trial

IMPORTANCE

COVID-19 vaccine uptake among urban populations remains low.

OBJECTIVE

To evaluate whether text messaging with outbound or inbound scheduling and behaviorally informed content might increase COVID-19 vaccine uptake.

DESIGN, SETTING, AND PARTICIPANTS

This randomized clinical trial with a factorial design was conducted from April 29 to July 6, 2021, in an urban academic health system. The trial comprised 16 045 patients at least 18 years of age in Philadelphia, Pennsylvania, with at least 1 primary care visit in the past 5 years, or a future scheduled primary care visit within the next 3 months, who were unresponsive to prior outreach. The study was prespecified in the trial protocol, and data were obtained from the intent-to-treat population.

INTERVENTIONS

Eligible patients were randomly assigned in a 1:20:20 ratio to (1) outbound telephone call only by call center, (2) text message and outbound telephone call by call center to those who respond, or (3) text message, with patients instructed to make an inbound telephone call to a hotline. Patients in groups 2 and 3 were concurrently randomly assigned in a 1:1:1:1 ratio to receive different content: standard messaging, clinician endorsement (eg, "Dr. XXX recommends"), scarcity ("limited supply available"), or endowment framing ("We have reserved a COVID-19 vaccine appointment for you").

MAIN OUTCOMES AND MEASURES

The primary outcome was the proportion of patients who completed the first dose of the COVID-19 vaccine within 1 month, according to the electronic health record. Secondary outcomes were the completion of the first dose within 2 months and completion of the vaccination series within 2 months of initial outreach. Additional outcomes included the percentage of patients with invalid cell phone numbers (wrong number or nontextable), no response to text messaging, the percentage of patients scheduled for the vaccine, text message responses, and the number of telephone calls made by the access center. Analysis was on an intention-to-treat basis.

RESULTS

Among the 16 045 patients included, the mean (SD) age was 36.9 (11.1) years; 9418 (58.7%) were women; 12 869 (80.2%) had commercial insurance, and 2283 (14.2%) were insured by Medicaid; 8345 (52.0%) were White, 4706 (29.3%) were Black, and 967 (6.0%) were Hispanic or Latino. At 1 month, 14 of 390 patients (3.6% [95% CI, 1.7%-5.4%]) in the outbound telephone call-only group completed 1 vaccine dose, as did 243 of 7890 patients (3.1% [95% CI, 2.7%-3.5%]) in the text plus outbound call group (absolute difference, -0.5% [95% CI, -2.4% to 1.4%]; P = .57) and 253 of 7765 patients (3.3% [95% CI, 2.9%-3.7%]) in the text plus inbound call group (absolute difference, -0.3% [95% CI, -2.2% to 1.6%]; P = .72). Among the 15 655 patients receiving text messaging, 118 of 3889 patients (3.0% [95% CI, 2.5%-3.6%]) in the standard messaging group completed 1 vaccine dose, as did 135 of 3920 patients (3.4% [95% CI, 2.9%-4.0%]) in the clinician endorsement group (absolute difference, 0.4% [95% CI, -0.4% to 1.2%]; P = .31), 100 of 3911 patients (2.6% [95% CI, 2.1%-3.1%]) in the scarcity group (absolute difference, -0.5% [95% CI, -1.2% to 0.3%]; P = .20), and 143 of 3935 patients (3.6% [95% CI, 3.0%-4.2%]) in the endowment group (absolute difference, 0.6% [95% CI, -0.2% to 1.4%]; P = .14).

CONCLUSIONS AND RELEVANCE

There was no detectable increase in vaccination uptake among patients receiving text messaging compared with telephone calls only or behaviorally informed message content.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04834726.

Payments and freedoms: Effects of monetary and legal incentives on COVID-19 vaccination intentions in Germany

Monetary and legal incentives have been proposed to promote COVID-19 vaccination uptake. To evaluate the suitability of incentives, an experiment with German participants examined the effects of payments (varied within subjects: 0 to 10,000 EUR) and freedoms (varied between subjects: vaccination leading vs. not leading to the same benefits as a negative test result) on the vaccination intentions of previously unvaccinated individuals (n = 782) in April 2021. While no effect could be found for freedoms, the share of participants willing to be vaccinated increased with the payment amount. However, a significant change required large rewards of 3,250 EUR or more. While monetary incentives could increase vaccination uptake by a few percentage points, the high costs of implementation challenge the efficiency of the measure and call for alternatives. As the data suggest that considering vaccination as safe, necessary, and prosocial increases an individual’s likelihood of wanting to get vaccinated without payment, interventions should focus on these features when promoting vaccination against COVID-19.

Which hospital workers do (not) want the jab? Behavioral correlates of COVID-19 vaccine willingness among employees of Swiss hospitals

In many countries, the current vaccination rates are stagnating, to the extent that vaccine hesitancy—the delay or refusal to take recommended vaccinations—forms a major obstacle to ending the COVID-19 pandemic. This tendency is particularly concerning when observed among healthcare workers who are opinion leaders on medical matters for their patients and peers. Our study surveys 965 employees of two large Swiss hospitals and profiles vaccine-hesitant hospital employees using not only socio-demographic characteristics, but also a comprehensive set of standard behavioral preference measures: (i) Big-5 personality traits, (ii) risk-, time- and social preferences, and (iii) perceived prevailing social norms. Using multinomial probit models and linear probability models, we find that vaccine-hesitant hospital employees are less patient and less likely to perceive vaccination as the prevailing social norm—in addition to replicating previously published socio-demographic results. Our findings are robust to a range of model specifications, as well as individual and situational covariates. Our study thus offers actionable policy implications for tailoring public-health communications to vaccine-hesitant hospital employees.

Vaccine Hesitancy and Betrayal Aversion

The determinants of vaccine hesitancy remain complex and context specific. Betrayal aversion occurs when an individual is hesitant to risk being betrayed in an environment involving trust. In this pre-registered vignette experiment, we show that betrayal aversion is not captured by current vaccine hesitancy measures despite representing a significant source of unwillingness to be vaccinated. Our survey instrument was administered to 888 United States residents via Amazon Mechanical Turk in March 2021. We find that over a third of participants have betrayal averse preferences, resulting in an 8–26% decline in vaccine acceptance, depending on the betrayal source. Interestingly, attributing betrayal risk to scientists or government results in the greatest declines in vaccine acceptance. We explore an exogenous message intervention and show that an otherwise effective message acts narrowly and fails to reduce betrayal aversion. Our results demonstrate the importance of betrayal aversion as a preference construct in the decision to vaccinate.

Politicizing mask-wearing: predicting the success of behavioral interventions among republicans and democrats in the U.S

Scientists and policymakers seek to choose effective interventions that promote preventative health measures. We evaluated whether academics, behavioral science practitioners, and laypeople (N = 1034) were able to forecast the effectiveness of seven different messages compared to a baseline message for Republicans and Democrats separately. These messages were designed to nudge mask-wearing attitudes, intentions, and behaviors. When examining predictions across political parties, forecasters predicted larger effects than those observed for Democrats compared to Republicans and made more accurate predictions for Republicans compared to Democrats. These results are partly driven by a lack of nudge effects on Democrats, as reported in Gelfand et al. (J Exp Soc Psychol, 2021). Academics and practitioners made more accurate predictions compared to laypeople. Although forecasters' predictions were correlated with the nudge interventions, all groups overestimated the observed results. We discuss potential reasons for why the forecasts did not perform better and how more accurate forecasts of behavioral intervention outcomes could potentially provide insight that can help save resources and increase the efficacy of interventions.

Explaining higher Covid-19 vaccination among some US primary care professionals

Background and objective

Research in several countries shows higher Covid-19 vaccination willingness and uptake among physicians than nurses. Our paper aims to characterize and explain this difference.

Methods

In early 2021, we surveyed 1047 U.S. primary care professionals who served adolescents, ages 11–17. The national sample included physicians (71%) as well as nurses and advanced practice providers. The survey assessed the three domains of the Increasing Vaccination Model: thinking and feeling, social processes, and direct behavior change.

Results

Covid-19 vaccine uptake was higher among physicians than among nurses and advanced practice providers (91% vs. 76%, p < .05). Overall, in the thinking and feeling domain, higher confidence in Covid-19 vaccination, higher perceived susceptibility to the disease, and stronger anticipated regret were associated with higher vaccine uptake (all p < .05). In the social processes domain, perceiving more positive social norms for Covid-19 vaccination, receiving recommendations to get the vaccine, and wanting to help others were associated with higher vaccine uptake (all p < .05). In the direct behavior change domain, receiving an invitation to get the vaccine and better access to vaccination were associated with higher uptake (both p < .05). Of these variables, most of the thinking and feeling and social processes variables mediated the association of training with vaccine uptake.

Conclusions

Physicians had higher Covid-19 vaccine uptake than nurses and advanced practice providers, corresponding with their more supportive vaccine beliefs and social experiences. Efforts to reach the remaining unvaccinated cohort can build on these findings.

Gearing Up for a Vaccine Requirement: A Mixed Methods Study of COVID-19 Vaccine Confidence Among Workers at an Academic Medical Center

GOAL

Assessing barriers to vaccination among healthcare workers may be particularly important given their roles in their respective communities. We conducted a mixed methods study to explore healthcare worker perspectives on receiving COVID-19 vaccines at a large multisite academic medical center.

METHODS

A total of 5,917 employees completed the COVID-19 vaccine confidence survey (20% response rate). Most participants were vaccinated (93%). Compared to vaccinated participants, unvaccinated participants were younger (60% < 44 years), more likely to be from a non-Asian minority group (48%), and more likely to be nonclinical employees (57% vs. 46%). Among the unvaccinated respondents, 53% indicated they would be influenced by their healthcare provider, while 19% reported that nothing would influence them to get vaccinated. Key perceived barriers to vaccination from the qualitative analysis included the need for more long-term safety and efficacy data, a belief in the right to make an individual choice, mistrust, a desire for greater public health information, personal health concerns, circumstances such as prior COVID-19 infection, and access issues.

PRINCIPAL FINDINGS

Strategies endorsed by some participants to address their concerns about safety and access included a communication campaign, personalized medicine approaches (e.g., individual appointments to discuss how the vaccine might interact with personal health conditions), and days off to recover. Mistrust and a belief in the right to make an individual choice may be harder barriers to overcome; further dialogue is needed.

APPLICATIONS TO PRACTICE

These findings reflect potential strategies for vaccine requirements that healthcare organizations can implement to enhance vaccine confidence. In addition, organizations can ask respected health professionals to serve as spokespeople, which may help shift the perspectives of unvaccinated healthcare workers.

COVID-19 vaccine hesitancy in eight European countries: Prevalence, determinants, and heterogeneity

We examine heterogeneity in COVID-19 vaccine hesitancy across eight European countries. We reveal striking differences across countries, ranging from 6.4% of adults in Spain to 61.8% in Bulgaria reporting being hesitant. We experimentally assess the effectiveness of different messages designed to reduce COVID-19 vaccine hesitancy. Receiving messages emphasizing either the medical benefits or the hedonistic benefits of vaccination significantly increases COVID-19 vaccination willingness in Germany, whereas highlighting privileges contingent on holding a vaccination certificate increases vaccination willingness in both Germany and the United Kingdom. No message has significant positive effects in any other country. Machine learning-based heterogeneity analyses reveal that treatment effects are smaller or even negative in settings marked by high conspiracy beliefs and low health literacy. In contrast, trust in government increases treatment effects in some groups. The heterogeneity in vaccine hesitancy and responses to different messages suggests that health authorities should avoid one-size-fits-all vaccination campaigns.

Video-based messages to reduce COVID-19 vaccine hesitancy and nudge vaccination intentions

Vaccines are highly effective for curbing the spread of SARS-CoV-2 (COVID-19). Yet, millions of Americans remain hesitant about getting vaccinated, jeopardizing our ability to end the COVID-19 pandemic by fueling the spread and development of new variants. We show that brief video-based messages of encouragement addressing specific COVID-19 vaccine concerns increase vaccination intentions, and that vaccination intentions, in turn, are predictive of future vaccine uptake. Results from our online experiment reveal that willingness to get vaccinated is driven by messages that increase confidence in COVID-19 vaccines and perceived behavioral control to get vaccinated. Importantly, messages were particularly effective among more skeptical populations including people who identify as politically conservative or moderate and those who express low trust in government institutions. Our findings corroborate the real-world behavioral significance of vaccination intentions, and devise how even short, scalable online messages can provide governments and health authorities an inexpensive, yet effective tool for increasing intentions to vaccinate against COVID-19 among populations most reluctant to get them.

Lau K, Miraldo M, Hauck K. Bandwagoning, free-riding and heterogeneity in influenza vaccine decisions: An online experiment

'Nudge'-based social norms messages conveying high population influenza vaccination coverage levels can encourage vaccination due to bandwagoning effects but also discourage vaccination due to free-riding effects on low risk of infection, making their impact on vaccination uptake ambiguous. We develop a theoretical framework to capture heterogeneity around vaccination behaviors, and empirically measure the causal effects of different messages about vaccination coverage rates on four self-reported and behavioral vaccination intention measures. In an online experiment, N = 1365 UK adults are randomly assigned to one of seven treatment groups with different messages about their social environment's coverage rate (varied between 10% and 95%), or a control group with no message. We find that treated groups have significantly greater vaccination intention than the control. Treatment effects increase with the coverage rate up to a 75% level, consistent with a bandwagoning effect. For coverage rates above 75%, the treatment effects, albeit still positive, stop increasing and remain flat (or even decline). Our results suggest that, at higher coverage rates, free-riding behavior may partially crowd out bandwagoning effects of coverage rate messages. We also find significant heterogeneity of these effects depending on the individual perceptions of risks of infection and of the coverage rates.

Deep-seated psychological histories of COVID-19 vaccine hesitance and resistance

To design effective pro-vaccination messaging, it is important to know “where people are coming from”—the personal experiences and long-standing values, motives, lifestyles, preferences, emotional tendencies, and information-processing capacities of people who end up resistant or hesitant toward vaccination. We used prospective data from a 5-decade cohort study spanning childhood to midlife to construct comprehensive early-life psychological histories of groups who differed in their vaccine intentions in months just before COVID vaccines became available in their country. Vaccine-resistant and vaccine-hesitant participants had histories of adverse childhood experiences that foster mistrust, longstanding mental-health problems that foster misinterpretation of messaging, and early-emerging personality traits including tendencies toward extreme negative emotions, shutting down mentally under stress, nonconformism, and fatalism about health. Many vaccine-resistant and -hesitant participants had cognitive difficulties in comprehending health information. Findings held after control for socioeconomic origins. Vaccine intentions are not short-term isolated misunderstandings. They are part of a person’s style of interpreting information and making decisions that is laid down before secondary school age. Findings suggest ways to tailor vaccine messaging for hesitant and resistant groups. To prepare for future pandemics, education about viruses and vaccines before or during secondary schooling could reduce citizens’ level of uncertainty during a pandemic, and provide people with pre-existing knowledge frameworks that prevent extreme emotional distress reactions and enhance receptivity to health messages. Enhanced medical technology and economic resilience are important for pandemic preparedness, but a prepared public who understands the need to mask, social distance, and vaccinate will also be important.

The Effectiveness of Interventions for Increasing COVID-19 Vaccine Uptake: A Systematic Review

Vaccination is vital to protect the public against COVID-19. The aim of this systematic review is to identify and evaluate the effectiveness of interventions to increase COVID-19 vaccine uptake. We searched a range of databases (Embase, Medline, Psychology & Behavioral Science, PsycInfo, Web of Science and NIH Preprints Portfolio) from March 2020 to July 2021 for studies which reported primary quantitative or qualitative research on interventions to increase COVID-19 vaccine uptake. Outcome measures included vaccination uptake and reported intention to vaccinate. Reviews, position papers, conference abstracts, protocol papers and papers not in English were excluded. The NHLBI quality assessment was used to assess risk of bias. In total, 39 studies across 33 papers met the inclusion criteria. A total of 28 were assessed as good quality. They included interventions relating to communication content, communication delivery, communication presentation, policy or vaccination delivery, with 7 measuring vaccination uptake and 32 measuring vaccination intention. A narrative synthesis was conducted, which highlighted that there is reasonable evidence from studies investigating real behaviour suggesting that personalising communications and sending booking reminders via text message increases vaccine uptake. Findings on vaccination intention are mixed but suggest that communicating uncertainty about the vaccine does not decrease intention, whereas making vaccination mandatory could have a negative impact. Although much of the research used experimental designs, very few measured real behavioural outcomes. Understanding which interventions are most effective amongst vaccine-hesitant populations and in the context of booster vaccinations will be important as vaccine roll outs continue across the world.

Behavioral Nudges to Improve Audit and Feedback Report Opening among Antibiotic Prescribers: A Randomized Controlled Trial

Background

Peer comparison audit and feedback has demonstrated effectiveness in improving antibiotic prescribing practices, but only a minority of prescribers view their reports. We rigorously tested three behavioral nudging techniques delivered by email to improve report opening.

Methods

We conducted a pragmatic randomized controlled trial among Ontario long-term care (LTC) prescribers enrolled in an ongoing peer comparison audit and feedback program which includes data on their antibiotic prescribing patterns. Physicians were randomized to 1 of 8 possible sequences of intervention/control allocation to 3 different behavioral email nudges: a social peer comparison nudge (January 2020), a maintenance of professional certification incentive nudge (October 2020), and a prior participation nudge (January 2021). The primary outcome was feedback report opening; the primary analysis pooled the effects of all 3 nudging interventions.

Results

The trial included 421 physicians caring for more than 28,000 residents at 450 facilities. In the pooled analysis, physicians opened only 29.6% of intervention and 23.9% of control reports (odds ratio (OR) 1.51 (95%CI 1.10-2.07, p=0.011); this difference remained significant after accounting for physician characteristics and clustering (adjusted OR (aOR) 1.74 (95%CI 1.24-2.45, p=0.0014). Of individual nudging techniques, the prior participation nudge was associated with a significant increase in report opening (OR 1.62, 95%CI 1.06-2.47, p=0.026; aOR 2.16, 95%CI 1.33-3.50, p=0.0018). In the pooled analysis, nudges were also associated with accessing more report pages (aOR 1.28, 95%CI 1.14-1.43, p&lt;0.001).

Conclusions

Enhanced nudging strategies modestly improved report opening, but more work is needed to optimize physician engagement with audit and feedback.

A 680,000-person megastudy of nudges to encourage vaccination in pharmacies

Encouraging vaccination is a pressing policy problem. To assess whether text-based reminders can encourage pharmacy vaccination and what kinds of messages work best, we conducted a megastudy. We randomly assigned 689,693 Walmart pharmacy patients to receive one of 22 different text reminders using a variety of different behavioral science principles to nudge flu vaccination or to a business-as-usual control condition that received no messages. We found that the reminder texts that we tested increased pharmacy vaccination rates by an average of 2.0 percentage points, or 6.8%, over a 3-mo follow-up period. The most-effective messages reminded patients that a flu shot was waiting for them and delivered reminders on multiple days. The top-performing intervention included two texts delivered 3 d apart and communicated to patients that a vaccine was "waiting for you." Neither experts nor lay people anticipated that this would be the best-performing treatment, underscoring the value of simultaneously testing many different nudges in a highly powered megastudy.