Crowdsourcing as a tool for creating effective nudges: An example for financial oversubscription.

Creating effective nudges, or interventions that encourage people to make choices that increase their welfare, is difficult to execute well. Recent work on megastudies, massive field experiments that test many interventions simultaneously, reveals that nudge effectiveness both varies widely and is difficult for experts to predict. We propose an Iterative Crowdsourcing Procedure, which uses insights from members of the target population to generate and preselect nudges prior to testing them in a field experiment. This technique can supplement existing methods or stand alone as a way to generate conditions for testing in a high-quality field experiment. We test the effectiveness of this method in addressing a challenge to effective financial management: consumer oversubscription. We first document that people have more subscriptions than they think they have and that enhancing subscription awareness makes people want to cancel some subscriptions. We then use our crowdsourcing procedure to motivate people toward subscription awareness in a field experiment (N = 4,412,113) with a large bank. We find that the crowdsourced nudges outperform those generated by the bank, demonstrating that the Iterative Crowdsourcing Procedure is a useful way to generate effective nudges.

System-, teacher-, and student-level interventions for improving participation in online learning at scale in high schools.

Many school systems across the globe turned to online education during the COVID-19 pandemic. This context differs significantly from the prepandemic situation in which massive open online courses attracted large numbers of voluntary learners who struggled with completion. Students who are provided online courses by their high schools also have their behavior determined by actions of their teachers and school system. We conducted experiments to improve participation in online learning before, during, and right after the COVID-19 outbreak, with 1,151 schools covering more than 45,000 students in their final years of high school in Ecuador. These experiments tested light-touch interventions at scale, motivated by behavioral science, and were carried out at three levels: that of the system, teacher, and student. We find the largest impacts come from intervening at the system level. A cheap, online learning management system for centralized monitoring increased participation by 0.21 SD and subject knowledge by 0.13 SD relative to decentralized management. Centralized management is particularly effective for underperforming schools. Teacher-level nudges in the form of benchmarking emails, encouragement messages, and administrative reminders did not improve student participation. There was no significant impact of encouragement messages to students, or in having them plan and team-up with peers. Small financial incentives in the form of lottery prizes for finishing lessons did increase study time, but was less cost-effective, and had no significant impact on knowledge. The results show the difficulty in incentivizing online learning at scale, and a key role for central monitoring.

Reminders, but not monetary incentives, increase COVID-19 booster uptake.

Despite substantially decreasing the risk of hospitalization and death from COVID-19, COVID-19 booster vaccination rates remain low around the world. A key question for public health agencies is how to increase booster vaccination rates, particularly among high-risk groups. We conducted a large preregistered randomized controlled trial (with 57,893 study subjects) in a county health system in northern California to test the impact of personal reminder messages and small financial incentives of $25 on booster vaccination rates. We found that reminders increased booster vaccination rates within 2 wk by 0.86 percentage points (P = 0.000) or nearly 33% off the control mean of 2.65%. Monetary incentives had no additional impact on vaccination rates. The results highlight the potential of low-cost targeted messages, but not small financial incentives, to increase booster vaccination rates.

What can machine learning teach us about habit formation? Evidence from exercise and hygiene.

We apply a machine learning technique to characterize habit formation in two large panel data sets with objective measures of 1) gym attendance (over 12 million observations) and 2) hospital handwashing (over 40 million observations). Our Predicting Context Sensitivity (PCS) approach identifies context variables that best predict behavior for each individual. This approach also creates a time series of overall predictability for each individual. These time series predictability values are used to trace a habit formation curve for each individual, operationalizing the time of habit formation as the asymptotic limit of when behavior becomes highly predictable. Contrary to the popular belief in a "magic number" of days to develop a habit, we find that it typically takes months to form the habit of going to the gym but weeks to develop the habit of handwashing in the hospital. Furthermore, we find that gymgoers who are more predictable are less responsive to an intervention designed to promote more gym attendance, consistent with past experiments showing that habit formation generates insensitivity to reward devaluation.

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.

The effectiveness of nudging: A meta-analysis of choice architecture interventions across behavioral domains.

Over the past decade, choice architecture interventions or so-called nudges have received widespread attention from both researchers and policy makers. Built on insights from the behavioral sciences, this class of behavioral interventions focuses on the design of choice environments that facilitate personally and socially desirable decisions without restricting people in their freedom of choice. Drawing on more than 200 studies reporting over 450 effect sizes (n = 2,149,683), we present a comprehensive analysis of the effectiveness of choice architecture interventions across techniques, behavioral domains, and contextual study characteristics. Our results show that choice architecture interventions overall promote behavior change with a small to medium effect size of Cohen's d = 0.45 (95% CI [0.39, 0.52]). In addition, we find that the effectiveness of choice architecture interventions varies significantly as a function of technique and domain. Across behavioral domains, interventions that target the organization and structure of choice alternatives (decision structure) consistently outperform interventions that focus on the description of alternatives (decision information) or the reinforcement of behavioral intentions (decision assistance). Food choices are particularly responsive to choice architecture interventions, with effect sizes up to 2.5 times larger than those in other behavioral domains. Overall, choice architecture interventions affect behavior relatively independently of contextual study characteristics such as the geographical location or the target population of the intervention. Our analysis further reveals a moderate publication bias toward positive results in the literature. We end with a discussion of the implications of our findings for theory and behaviorally informed policy making.

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.

Effect of Electronic Nudges on Influenza Vaccination Rate in Older Adults With Cardiovascular Disease: Prespecified Analysis of the NUDGE-FLU Trial.

BACKGROUND: Influenza vaccines have been demonstrated to effectively reduce the incidence of influenza infection and potentially associated risks of cardiovascular events in patients with cardiovascular disease (CVD). Despite strong guideline and public health endorsements, global influenza vaccination rates in patients with CVD are highly variable. This prespecified analysis of NUDGE-FLU (Nationwide Utilization of Danish Government Electronic Letter System for Increasing Influenza Vaccine Uptake) examined the effect of digital behavioral nudges on influenza vaccine uptake based on the presence of CVD. METHODS: NUDGE-FLU was a randomized, pragmatic, nationwide, register-based trial that included Danish citizens 65 years of age or older during the 2022 to 2023 influenza season. Households were randomized in a 9:1:1:1:1:1:1:1:1:1 ratio to usual care or 9 electronic letters with designs based on behavioral concepts. Danish nationwide registers were used to collect baseline and outcome data. The primary end point was receipt of an influenza vaccine on or before January 1, 2023. The effects of the intervention letters were examined according to the presence of CVD and across cardiovascular subgroups that included heart failure, ischemic heart disease, and atrial fibrillation. RESULTS: Of 964 870 NUDGE-FLU participants from 691 820 households, 264 392 (27.4%) had CVD. During follow-up, 83.1% of participants with CVD versus 79.2% of participants without CVD received an influenza vaccination (P<0.001). Compared with usual care, a letter emphasizing the potential cardiovascular benefits of influenza vaccination increased vaccination rates; this effect was consistent in participants with CVD (absolute difference, +0.60 percentage points [99.55% CI, -0.48 to 1.68]) and without CVD (+0.98 percentage points [99.55% CI, 0.27-1.70; P for interaction=0.41). A repeated letter strategy with a reminder follow-up letter 14 days later was also effective in increasing influenza vaccination, irrespective of CVD (CVD: absolute difference, +0.80 percentage points [99.55% CI, -0.27 to 1.86]; no CVD: +0.67 percentage points [99.55% CI, -0.06 to 1.40]; P for interaction=0.77). Effectiveness of both nudging strategies was consistent across all major CVD subgroups. None of the other 7 nudging strategies were effective, regardless of CVD status. CONCLUSIONS: Electronic letter interventions emphasizing the potential cardiovascular benefits of influenza vaccination and using a reminder letter strategy were similarly beneficial in increasing influenza vaccination rates among older adults with and without CVD and across cardiovascular subgroups. Electronic nudges may improve influenza vaccine uptake in individuals with CVD. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT05542004.

Impacts of ecosystem service message framing and dynamic social norms on public support for tropical forest restoration.

The effectiveness of strategic psychology-based marketing techniques for increasing public support for conservation is poorly understood. We assessed how such techniques affect support for tropical rainforest restoration with a controlled online experiment with 1166 nationally representative residents of the United Kingdom. We tested whether support increased when adding ecosystem service (ES) framings to typical nongovernmental organizations' (NGOs) biodiversity-focused messages that emphasize benefits to UK residents or people living near the tropical restoration site and a dynamic social norm nudge that emphasized increasing popularity of environmental restoration. We considered how respondents' psychological traits (nature connection, self-efficacy, psychological benefits of supporting charities, awareness of environmental degradation in the Global South, and climate change skepticism) influenced responses. Outcomes included respondents' reported advertisement sufficiency, sympathetic attitudes, behavioral support, and financial support. The study population typically found advertisements sufficient and exhibited sympathetic attitudes and financial, but not behavioral, support. Younger people exhibited greater conservation support than older respondents. Messages framed solely on biodiversity conservation were as effective as those highlighting additional ES benefits received by UK residents and people near the tropical restoration site. This suggests that framing around ESs, rather than nature's intrinsic value, may not strengthen public support for conservation. The dynamic social norm nudge had perverse effects. It reduced perceived social norms and most outcome variables. Alternative dynamic norm nudges warrant testing, but our results support research suggesting dynamic norm nudges can be ineffective when associated with activism, challenging their use by conservation NGOs. Psychological benefits of supporting charities and perceived self-efficacy increased support for advertisements, highlighting the benefits of including impact statements relating respondents' support to specific outcomes. Climate change skepticism decreased support, whereas nature connection and perceived static social norms increased it, highlighting the need to increase nature connection and pro-environmental social norms to elevate public support for conservation.

Impactos del encuadre de los mensajes sobre servicios ambientales y las normas sociales dinámicas sobre el apoyo público hacia la restauración de bosques tropicales Resumen Sabemos poco sobre la eficiencia de las técnicas de mercadotecnia basadas en la psicología estratégica para aumentar el apoyo público a la conservación. Evaluamos cómo afectan dichas técnicas al apoyo a la restauración de la selva tropical mediante un experimento controlado en línea con 1,166 residentes del Reino Unido representativos a nivel nacional. Comprobamos si el apoyo aumentaba al añadir marcos de servicios ambientales a los mensajes típicos de las organizaciones no gubernamentales (ONG) centrados en la biodiversidad, que hacen hincapié en los beneficios para los residentes del Reino Unido o las personas que viven cerca del lugar de restauración tropical y un empuje dinámico de normas sociales que hacía hincapié en la creciente popularidad de la restauración ecológica. Analizamos la influencia de los rasgos psicológicos de los encuestados (conexión con la naturaleza, autoeficacia, beneficios psicológicos de apoyar a organizaciones benéficas, experiencia de degradación ambiental en el Sur Global y escepticismo ante el cambio climático) sobre las respuestas. Los resultados fueron la suficiencia de los anuncios, las actitudes de simpatía, el apoyo conductual y el apoyo económico. En general, la población del estudio consideró que los anuncios eran suficientes y mostró actitudes de simpatía y apoyo económico, pero no conductuales. La población más joven mostró un mayor apoyo a la conservación que los encuestados de más edad. Los mensajes centrados únicamente en la conservación de la biodiversidad fueron tan eficaces como los que destacaban los beneficios adicionales de los servicios ambientales recibidos por los residentes del Reino Unido y las personas cercanas al lugar de restauración tropical. Esto sugiere que el encuadre en torno a los servicios ambientales, en lugar del valor intrínseco de la naturaleza, puede no reforzar el apoyo público a la conservación. El empuje dinámico de la norma social tuvo efectos perversos ya que redujo las normas sociales percibidas y la mayoría de las variables de resultado. Es necesario probar otros incentivos dinámicos, pero nuestros resultados corroboran las investigaciones que sugieren que los incentivos dinámicos pueden ser ineficaces cuando se asocian con el activismo, lo que cuestiona su uso por parte de las ONG de la conservación. Los beneficios psicológicos por apoyar a organizaciones benéficas y la autoeficacia percibida aumentaron el apoyo a los anuncios, lo que resalta las ventajas de incluir declaraciones de impacto que relacionen el apoyo de los encuestados con resultados específicos. El escepticismo ante el cambio climático redujo el apoyo, mientras que la conexión con la naturaleza y las normas sociales estáticas percibidas lo aumentaron, lo que destaca la necesidad de aumentar la conexión con la naturaleza y las normas sociales proambientales para elevar el apoyo público a la conservación.

Examining the effectiveness of promotional nudges increasing plant-based food choices in a post-secondary education dining hall: a pilot study.

OBJECTIVE: To evaluate nudge strategies that increase the consumption of plant-based foods, defined as vegetarian or vegan food items, compared with meat-based options in post-secondary dining hall settings. DESIGN: A pilot study. SETTING: This study took place in the University of British Columbia Vancouver Campus's Gather Dining Hall (GDH) over a 6-week intervention period and two control periods. The intervention incorporated several nudges (proportion increases, item placement, taste-focused labelling, Chef's featured special verbal prompts, social media and promotional posters) into the menu and dining hall area with the goal of increasing the purchases of plant-based items. Sales data from meals that were purchased during the intervention period were compared with sales data from the two control periods. PARTICIPANTS: Students and staff who purchased meals in the GDH. RESULTS: The proportion of plant-based items sold significantly increased during the intervention period (56·7 %; P < 0·01) compared with the last 6 weeks of term one (53·6 %) and the first 6 weeks of term two (53·4 %). The proportion of plant-based 'main' menu items was significantly higher in the intervention period (46·4; P < 0·01) when compared with the last 6 weeks of term one (40·9 %) and the first 6 weeks of term two (41·7 %). CONCLUSIONS: The combination of nudges was effective at significantly increasing the selection of plant-based options over meat-based options in a post-secondary dining hall setting.

Process evaluation of a tailored nudge intervention to promote appropriate care and treatment of older patients at the end-of-life.

BACKGROUND: Non-beneficial treatment affects a considerable proportion of older people in hospital, and some will choose to decline invasive treatments when they are approaching the end of their life. The Intervention for Appropriate Care and Treatment (InterACT) intervention was a 12-month stepped wedge randomised controlled trial with an embedded process evaluation in three hospitals in Brisbane, Australia. The aim was to increase appropriate care and treatment decisions for older people at the end-of-life, through implementing a nudge intervention in the form of a prospective feedback loop. However, the trial results indicated that the expected practice change did not occur. The process evaluation aimed to assess implementation using the Consolidated Framework for Implementation Research, identify barriers and enablers to implementation and provide insights into the lack of effect of the InterACT intervention. METHODS: Qualitative data collection involved 38 semi-structured interviews with participating clinicians, members of the executive advisory groups overseeing the intervention at a site level, clinical auditors, and project leads. Online interviews were conducted at two times: implementation onset and completion. Data were coded to the Consolidated Framework for Implementation Research and deductively analysed. RESULTS: Overall, clinicians felt the premise and clinical reasoning behind InterACT were strong and could improve patient management. However, several prominent barriers affected implementation. These related to the potency of the nudge intervention and its integration into routine clinical practice, clinician beliefs and perceived self-efficacy, and wider contextual factors at the health system level. CONCLUSIONS: An intervention designed to change clinical practice for patients at or near to end-of-life did not have the intended effect. Future interventions targeting this area of care should consider using multi-component strategies that address the identified barriers to implementation and clinician change of practice. TRIAL REGISTRATION: Australia New Zealand Clinical Trial Registry (ANZCTR), ACTRN12619000675123p (approved 06/05/2019).

Applying a deterrence nudge strategy for promoting stair usage in a university setting.

PURPOSE: This study aimed to examine whether indirectly deterring elevator use through time-targeted Point-of-Decision Prompts (PODPs) efficiently increased stair usage in a university setting. METHODS: A quasi-experimental design (pre-post design) was employed over 2 weeks in September 2023. Baseline observations were conducted for 1 week prior to signage placement at two locations. The intervention in this study lasted for 1 week, immediately following baseline observations. Three hundred and thirty-one and 384 participants were observed during the baseline and intervention periods, respectively. Logistic regression analysis was used to examine the increase in the act of ascending the stairs. RESULTS: Our intervention, which focused on time-related messages, effectively increased stair usage among university students (coefficient = 0.435, p-value < 0.01). Furthermore, females (coefficient = -0.820, p-value < 0.05) and individuals aged ≥ 30 years (coefficient = 1.048, p-value < 0.01) were notably more likely to be influenced by our intervention than males and individuals aged < 30 years. CONCLUSION: Indirectly discouraging elevator use through time-targeted PODPs may amplify the effects of the previously employed time-related messages. Our findings suggested that a deterrence nudge should primarily be directed towards promoting stair usage among females or individuals aged ≥ 30 years.

Effectiveness of workplace choice architecture modification for healthy eating and daily physical activity.

BACKGROUND: Modifying the choice architecture of behavioural contexts can facilitate health behaviour change, but existing evidence builds mostly on small-scale interventions limited in duration, targets, strategies, and settings. We evaluated the effectiveness of a one-year hybrid type 2 implementation-effectiveness trial aimed at promoting healthy eating and daily physical activity with subtle modifications to the choice architecture of heterogeneous worksites. The intervention was contextualised to and integrated into the routine operations of each worksite. Effectiveness was evaluated in a quasi-experimental pre-post design. METHODS: Intervention sites (n = 21) implemented a median of two (range 1-9) intervention strategies for healthy eating and one (range 1-5) for physical activity. Questionnaires pre (n = 1126) and post (n = 943) intervention surveyed employees' behavioural patterns at work (food consumption: vegetables/roots, fruit/berries, nuts/almonds/seeds, sweet treats, fast food, water; physical activity: restorative movement, exercise equipment use, stair use). The post-intervention questionnaire also measured employees' perception of and response to three intervention strategies: a packed lunch recipe campaign, a fruit crew-strategy, and movement prompts. Multi- and single-level regression models evaluated effectiveness, treating intervention as a continuous predictor formed of the site-specific dose (n intervention strategies employed) and mean quality (three-point rating per strategy halfway and at the end of the intervention) of implementation relevant to each outcome. RESULTS: Multinomial logistic regression models found the intervention significantly associated with a favourable change in employees' fruit and berry consumption (interaction effect of time and implementation p = 0.006) and with an unfavourable change in sweet treat consumption (p = 0.048). The evidence was strongest for the finding concerning fruit/berry consumption-an outcome that sites with greater dose and quality of implementation targeted by using strategies that reduced the physical effort required to have fruit/berries at work and by covering multiple eating-related contexts at the worksite. The quality of implementation was positively associated with the perception of (p = 0.044) and response to (p = 0.017) the packed lunch recipes, and with response to the fruit crew-strategy (p < 0.001). CONCLUSIONS: The results suggest that a contextualised, multicomponent choice architecture intervention can positively influence eating behaviour in diverse real-world settings over a one-year period, and that higher implementation quality can enhance intervention perception and response. However, outcomes may depend on the type of intervention strategies used and the extent of their delivery.

Health or environment? Understanding which informative message is more effective in replacing red meat with mushroom-based alternatives.

Current concerns regarding the health and environmental consequences associated with excessive meat consumption have underscored the importance of guiding consumers towards more sustainable diets. Given this perspective, this study seeks to evaluate the effectiveness of tailored informative messages in shaping consumer behaviour, particularly within the framework of replacing meat with mushroom-based alternatives. Additionally, it explores the factors influencing informative message effectiveness. An experimental online survey was conducted on a sample of 951 Italian consumers. Specifically, the sample was divided into three groups, of which 309 individuals formed the control group, 311 participants received informative messages on the health risks associated with red meat consumption, and 331 participants received informative messages emphasizing the environmental damages linked to red meat consumption. In both treatments, there was support for mushroom-based alternatives. Analyses included subgroup assessments, tests to verify treatments effectiveness, along with OLS regression to pinpoint variables influencing message effectiveness. The results underscore a fair positive impact of the two informative messages (mean scores: 8.75 for health message; 7.01 for environmental message). Noteworthy psychosocial variables, including lifestyle patterns, nutritional perceptions, and ecological attitudes, emerged as determinants in shaping consumers' food choices. While health-related messages exhibit marked influence, the nuanced landscape of diverse drivers and barriers necessitates judicious communication strategies. These insights bear significance for policymakers, health professionals, and marketers, offering guidance for interventions that effectively influence consumer behaviour toward more sustainable and healthier food practices.

How do opt-in versus opt-out settings nudge patients toward electronic health record adoption? An exploratory study of facilitators and barriers in Austria and France.

BACKGROUND: Electronic health records (EHR) are becoming an integral part of the health system in many developed countries, though implementations and settings vary across countries. Some countries have adopted an opt-out policy, in which patients are enrolled in the EHR system following a default nudge, while others have applied an opt-in policy, where patients have to take action to opt into the system. While opt-in systems may exhibit lower levels of active user requests for access, this contrasts with opt-out systems where a notable percentage of users may passively retain access. Thus, our research endeavor aims to explore facilitators and barriers that contribute to explaining EHR usage (i.e., actively accessing the EHR system) in two countries with either an opt-in or opt-out setting, exemplified by France and Austria. METHODS: A qualitative exploratory approach using a semi-structured interview guideline was undertaken in both countries: 1) In Austria, with four homogenously composed group discussions, and 2) in France, with 19 single patient interviews. The data were collected from October 2020 to January 2021. RESULTS: Influencing factors were categorized into twelve subcategories. Patients have similar experiences in both countries with regard to all facilitating categories, for instance, the role of health providers, awareness of EHR and social norms. However, we highlighted important differences between the two systems regarding hurdles impeding EHR usage, namely, a lack of communication as well as transparency or information security about EHR. CONCLUSION: Implementing additional safeguards to enhance privacy protection and supporting patients to improve their digital ability may help to diminish the perception of EHR-induced barriers and improve patients' health and commitment in the long term. PRACTICAL IMPLICATIONS: Understanding the differences and similarities will help to develop practical implications to tackle the problem of low EHR usage rates in the long run. This problem is prevalent in countries with both types of EHR default settings.

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

Many Americans fail to get life-saving vaccines each year, and the availability of a vaccine for COVID-19 makes the challenge of encouraging vaccination more urgent than ever. We present a large field experiment (N = 47,306) testing 19 nudges delivered to patients via text message and designed to boost adoption of the influenza vaccine. Our findings suggest that text messages sent prior to a primary care visit can boost vaccination rates by an average of 5%. Overall, interventions performed better when they were 1) framed as reminders to get flu shots that were already reserved for the patient and 2) congruent with the sort of communications patients expected to receive from their healthcare provider (i.e., not surprising, casual, or interactive). The best-performing intervention in our study reminded patients twice to get their flu shot at their upcoming doctor's appointment and indicated it was reserved for them. This successful script could be used as a template for campaigns to encourage the adoption of life-saving vaccines, including against COVID-19.

Long-Term Effectiveness of a Multi-Strategy Choice Architecture Intervention in Increasing Healthy Food Choices of High-School Students From Online Canteens (Click & Crunch High Schools): Cluster Randomized Controlled Trial.

BACKGROUND: School canteens are a recommended setting to influence adolescent nutrition due to their scope to improve student food choices. Online lunch ordering systems ("online canteens") are increasingly used and represent attractive infrastructure to implement choice architecture interventions that nudge users toward healthier food choices. A recent cluster randomized controlled trial demonstrated the short-term effectiveness (2-month follow-up) of a choice architecture intervention to increase the healthiness of foods purchased by high school students from online canteens. However, there is little evidence regarding the long-term effectiveness of choice architecture interventions targeting adolescent food purchases, particularly those delivered online. OBJECTIVE: This study aimed to determine the long-term effectiveness of a multi-strategy choice architecture intervention embedded within online canteen infrastructure in high schools at a 15-month follow-up. METHODS: A cluster randomized controlled trial was undertaken with 1331 students (from 9 high schools) in New South Wales, Australia. Schools were randomized to receive the automated choice architecture intervention (including menu labeling, positioning, feedback, and prompting strategies) or the control (standard online ordering). The foods purchased were classified according to the New South Wales Healthy Canteen strategy as either "everyday," "occasional," or "should not be sold." Primary outcomes were the average proportion of "everyday," "occasional," and "should not be sold" items purchased per student. Secondary outcomes were the mean energy, saturated fat, sugar, and sodium content of purchases. Outcomes were assessed using routine data collected by the online canteen. RESULTS: From baseline to 15-month follow-up, on average, students in the intervention group ordered significantly more "everyday" items (+11.5%, 95% CI 7.3% to 15.6%; P<.001), and significantly fewer "occasional" (-5.4%, 95% CI -9.4% to -1.5%; P=.007) and "should not be sold" items (-6%, 95% CI -9.1% to -2.9%; P<.001), relative to controls. There were no between-group differences over time in the mean energy, saturated fat, sugar, or sodium content of lunch orders. CONCLUSIONS: Given their longer-term effectiveness, choice architecture interventions delivered via online canteens may represent a promising option for policy makers to support healthy eating among high school students. TRIAL REGISTRATION: Australian Clinical Trials ACTRN12620001338954, https://anzctr.org.au/Trial/Registration/TrialReview.aspx?id=380546 ; Open Science Framework osf.io/h8zfr, https://osf.io/h8zfr/.

Dark patterns, dark nudges, sludge and misinformation: alcohol industry apps and digital tools.

Many alcohol-industry-funded (AIF) organizations disseminate eHealth/mHealth tools that claim to assist users in making health decisions by monitoring alcohol consumption, e.g. blood alcohol calculators, AUDIT scores, consumption trackers. Previously, AIF materials were found to contain health misinformation that could increase consumption (dark nudges) or make healthy behaviour change more difficult (sludge). The accuracy and functionality of AIF tools have never been analysed, and given the history of AIF materials it is possible they contain misinformation and function as covert marketing channels to promote alcohol-industry-friendly narratives on the causes and possible solutions of alcohol-related harms. We evaluated the information accuracy and framing, behaviour change techniques (BCTs), and functions of AIF digital tools (n = 15, from the UK, Ireland, the USA, Canada, New Zealand, Australia; including Drinkaware, Drinkwise, Educ'alcool and others), compared to a non-industry-funded independent sample (n = 10). We identified misinformation and 'dark patterns' (interface design strategies for influencing users against their interest) throughout AIF tools; significantly fewer provided accurate feedback (33% vs 100%), and significantly more omitted information on cancer (67% vs 10%) and cardiovascular disease (80% vs 30%) and promoted industry-friendly narratives (47% vs 0%). AIF tools encouraged consumption through priming nudges (53%) and social norming (40%). AIF tools utilized fewer BCTs, provided users with more limited pre-set options (54%), and fewer drink choices (mean 24 vs 275). Their input structure often impeded their ability to provide guideline advice. We conclude that AIF tools contain pro-industry misinformation strategies and dark patterns that misinform users about their consumption and could 'nudge' them towards continuing to drink alcohol-characteristics of 'Dark Apps' designs.

Nurse-led sequential multiple assignment randomized trial of nudging intervention for early antiretroviral therapy initiation among patients with HIV/AIDS: Implementation study protocol.

AIMS: In China, more than 30% of patients have not initiated treatment within 30 days of HIV diagnosis. Delayed initiation has a detrimental influence on disease outcomes and increases HIV transmission. The study aims to evaluate the effectiveness of a nurse-led antiretroviral therapy initiation nudging intervention for people newly diagnosed with HIV in China to find the optimal intervention implementation strategy. METHODS: A Hybrid Type II sequential multiple assignment randomized trial will be conducted at four Centers for Disease Control and Prevention in Hunan, China. This study will recruit 447 people newly diagnosed with HIV aged ≥18 years and randomly assign them into two intervention groups and one control group. On top of the regular counselling services and referrals, intervention groups will receive a 4-week, 2-phase intervention based on the dual-system theory and the nudge theory. The control group will follow the currently recommended referral procedures. The primary outcomes are whether treatment is initiated, as well as the length of time it takes. The study outcomes will be measured at the baseline, day 15, day 30, week 12, week 24 and week 48. Generalized estimating equations and survival analysis will be used to compare effectiveness and explore factors associated with antiretroviral therapy initiation. Both qualitative and quantitative information will be collected to assess implementation outcomes. DISCUSSION: Existing strategies mostly target institutional-level factors, with little consideration given to patients' decision-making. To close this gap, we aim to develop an effective theory-driven nudging strategy to improve early ART initiation. IMPACT: This nurse-led study will help to prevent delayed initiation by employing implementation science strategies for people newly diagnosed with HIV. This study contributes to the United Nations' objective of ending the AIDS pandemic by 2030. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2300070140. The trial was prospectively registered before the first participant was recruited. PATIENT AND PUBLIC INVOLVEMENT: The nudging intervention was finalized through the Nominal Group Technique where we invited five experts in the related field and five people living with HIV to participate.

Frail Older Adults' Needs and Preferences for Mobile Health Exercise Interventions Guided by Nudge Theory: AQualitative Analysis.

AIM: To explore frail older adults' preferences and needs regarding mobile health (mHealth) exercise interventions in China. Additionally, it sought to identify the nudge strategies necessary for initiating and sustaining exercise behaviours among frail older adults. DESIGN: A qualitative study. METHOD: The semi-structured interviews were conducted between April and May 2024 from two communities in Changsha, China. The data were analysed using a deductive framework analysis aligned to nudge theory, and an inductive thematic analysis to gather relevant needs and preferences. RESULTS: This study involved 14 participants with pre-frailty or frailty, aged 60-82 years (median age of 64 years). While participants were generally receptive to new technologies, lower levels of health literacy and competing priorities often hindered their participation. Three primary functionality requirements were as follows. (1) Profession engagement: tailored exercise prescription, professional and timely feedback and guidance; (2) personalised knowledge encompassing pain management, successful cases and inspiration; (3) beneficial, tailored, dynamic, fragmented, challenging exercise courses. Participants showed positive attitudes towards simplification nudges, gamification nudges, social nudges, trustworthy nudges, reminder nudges, economic nudges, feedback nudges and pre-commitment nudges. Addressing privacy concerns was essential to build trust and acceptance among older adults. CONCLUSION: These findings emphasised the importance of designing mHealth interventions that address frail older adults' specific needs and preferences while incorporating effective nudge strategies to promote engagement and adherence. Future researchers should explore wearables, ChatGPT language models, virtual coaching assistants, exercise snack to further optimise the experience and analyse the effects of nudges in mHealth exercise interventions among older adults. IMPLICATION FOR THE PROFESSION AND/OR PATIENT CARE: Exercise systems or app development for frail older adults should meet three basic functionality and essential nudge strategies. REPORTING METHOD: The consolidated criteria for reporting qualitative research (COREQ) guidelines were used for reporting. PATIENT OR PUBLIC CONTRIBUTION: Older adults' engagement and interview data contribute a lot.