Exposing omitted moderators: Explaining why effect sizes differ in the social sciences.

Policymakers increasingly rely on behavioral science in response to global challenges, such as climate change or global health crises. But applications of behavioral science face an important problem: Interventions often exert substantially different effects across contexts and individuals. We examine this heterogeneity for different paradigms that underlie many behavioral interventions. We study the paradigms in a series of five preregistered studies across one in-person and 10 online panels, with over 11,000 respondents in total. We find substantial heterogeneity across settings and paradigms, apply techniques for modeling the heterogeneity, and introduce a framework that measures typically omitted moderators. The framework's factors (Fluid Intelligence, Attentiveness, Crystallized Intelligence, and Experience) affect the effectiveness of many text-based interventions, producing different observed effect sizes and explaining variations across samples. Moderators are associated with effect sizes through two paths, with the intensity of the manipulation and with the effect of the manipulation directly. Our results motivate observing these moderators and provide a theoretical and empirical framework for understanding and predicting varying effect sizes in the social sciences.

Dark defaults: How choice architecture steers political campaign donations.

In the months before the 2020 U.S. election, several political campaign websites added prechecked boxes (defaults), automatically making all donations into recurring weekly contributions unless donors unchecked them. Since these changes occurred at different times for different campaigns, we use a staggered difference-in-differences design to measure the causal effects of defaults on donors' behavior. We estimate that defaults increased campaign donations by over $43 million while increasing requested refunds by almost $3 million. The weekly default only impacted weekly recurring donations, and not other donations, suggesting that donors may not have intended to make weekly donations. The longer defaults were displayed, the more money campaigns raised through weekly donations. Donors did not compensate by changing the amount they donated. We found that the default had a larger impact on smaller donors and on donors who had no prior experience with defaults, causing them to start more chains and donate a larger proportion of their money through weekly recurring donations.

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.

A Randomized Trial of Choice Architecture and Mailed Colorectal Cancer Screening Outreach in a Community Health Setting.

BACKGROUND & AIMS: Mailed outreach for colorectal cancer (CRC) screening increases uptake but it is unclear how to offer the choice of testing. We evaluated if the active choice between colonoscopy and fecal immunochemical test (FIT), or FIT alone, increased response compared with colonoscopy alone. METHODS: This pragmatic, randomized, controlled trial at a community health center included patients between ages 50 and 74 who were not up to date with CRC screening. Patients were randomized 1:1:1 to the following: (1) colonoscopy only, (2) active choice of colonoscopy or FIT, or (3) FIT only. Patients received an outreach letter with instructions for testing (colonoscopy referral and/or an enclosed FIT kit), a reminder letter at 2 months, and another reminder at 3 to 5 months via text message or automated voice recording. The primary outcome was CRC screening completion within 6 months. RESULTS: Among 738 patients in the final analysis, the mean age was 58.7 years (SD, 6.2 y); 48.6% were insured by Medicaid and 24.3% were insured by Medicare; and 71.7% were White, 16.9% were Black, and 7.3% were Hispanic/Latino. At 6 months, 5.6% (95% CI, 2.8-8.5) completed screening in the colonoscopy-only arm, 12.8% (95% CI, 8.6-17.0) in the active-choice arm, and 11.3% (95% CI, 7.4-15.3) in the FIT-only arm. Compared with colonoscopy only, there was a significant increase in screening in active choice (absolute difference, 7.1%; 95% CI, 2.0-12.2; P = .006) and FIT only (absolute difference, 5.7%; 95% CI, 0.8-10.6; P = .02). CONCLUSIONS: Both choice of testing and FIT alone increased response and may align with patient preferences. TRIAL REGISTRATION: clinicaltrials.gov NCT04711473.

Real-world nudging, pricing, and mobile physical activity coaching was insufficient to improve lifestyle behaviours and cardiometabolic health: the Supreme Nudge parallel cluster-randomised controlled supermarket trial.

BACKGROUND: Context-specific interventions may contribute to sustained behaviour change and improved health outcomes. We evaluated the real-world effects of supermarket nudging and pricing strategies and mobile physical activity coaching on diet quality, food-purchasing behaviour, walking behaviour, and cardiometabolic risk markers. METHODS: This parallel cluster-randomised controlled trial included supermarkets in socially disadvantaged neighbourhoods across the Netherlands with regular shoppers aged 30-80 years. Supermarkets were randomised to receive co-created nudging and pricing strategies promoting healthier purchasing (N = 6) or not (N = 6). Nudges targeted 9% of supermarket products and pricing strategies 3%. Subsequently, participants were individually randomised to a control (step counter app) or intervention arm (step counter and mobile coaching app) to promote walking. The primary outcome was the average change in diet quality (low (0) to high (150)) over all follow-up time points measured with a validated 40-item food frequency questionnaire at baseline and 3, 6, and 12 months. Secondary outcomes included healthier food purchasing (loyalty card-derived), daily step count (step counter app), cardiometabolic risk markers (lipid profile and HbA1c via finger prick, and waist circumference via measuring tape), and supermarket customer satisfaction (questionnaire-based: very unsatisfied (1) to very satisfied (7)), evaluated using linear mixed-models. Healthy supermarket sales (an exploratory outcome) were analysed via controlled interrupted time series analyses. RESULTS: Of 361 participants (162 intervention, 199 control), 73% were female, the average age was 58 (SD 11) years, and 42% were highly educated. Compared to the control arm, the intervention arm showed no statistically significant average changes over time in diet quality (ߠ- 1.1 (95% CI - 3.8 to 1.7)), percentage healthy purchasing (ß 0.7 ( - 2.7 to 4.0)), step count (ߠ- 124.0 (- 723.1 to 475.1), or any of the cardiometabolic risk markers. Participants in the intervention arm scored 0.3 points (0.1 to 0.5) higher on customer satisfaction on average over time. Supermarket-level sales were unaffected (ß - 0.0 (- 0.0 to 0.0)). CONCLUSIONS: Co-created nudging and pricing strategies that predominantly targeted healthy products via nudges were unable to increase healthier food purchases and intake nor improve cardiometabolic health. The mobile coaching intervention did not affect step count. Governmental policy measures are needed to ensure more impactful supermarket modifications that promote healthier purchases. TRIAL REGISTRATION: Dutch Trial Register ID NL7064, 30 May 2018, https://www.onderzoekmetmensen.nl/en/trial/20990.

Are Dutch adults equally susceptible to nudging and pricing strategies? Secondary analyses of the Supreme Nudge parallel cluster-randomised controlled supermarket trial.

BACKGROUND: Supermarket interventions are promising to promote healthier dietary patterns, but not all individuals may be equally susceptible. We explored whether the effectiveness of nudging and pricing strategies on diet quality differs by psychological and grocery shopping characteristics. METHODS: We used data of the 12-month Supreme Nudge parallel cluster-randomised controlled supermarket trial, testing nudging and pricing strategies to promote healthier diets. Participants were Dutch speaking adults aged 30-80 years and regular shoppers of participating supermarkets (n = 12) in socially disadvantaged neighbourhoods. Data on psychological characteristics (food-related behaviours; price sensitivity; food decision styles; social cognitive factors; self-control) and grocery shopping characteristics (time spent in the supermarket; moment of the day; average supermarket visits; shopping at other retailers; supermarket proximity) were self-reported at baseline. These characteristics were tested for their moderating effects of the intervention on diet quality (scored 0-150) in linear mixed models. RESULTS: We included 162 participants from intervention supermarkets and 199 from control supermarkets (73% female, 58 (± 10.8) years old, 42% highly educated). The interventions had no overall effect on diet quality. Only five out of 23 potential moderators were statistically significant. Yet, stratified analyses of these significant moderators showed no significant effects on diet quality for one of the subgroups and statistically non-significant negative effects for the other. Negative effects were suggested for individuals with lower baseline levels of meal planning (ß - 2.6, 95% CI - 5.9; 0.8), healthy shopping convenience (ß - 3.0, 95% CI - 7.2; 1.3), and healthy food attractiveness (ß - 3.5, 95% CI - 8.3; 1.3), and with higher levels of price consciousness (ß - 2.6, 95% CI - 6.2; 1.0) and weekly supermarket visits (ß - 2.4, 95% CI - 6.8; 1.9). CONCLUSIONS: Adults with varying psychological and grocery shopping characteristics largely seem equally (un)susceptible to nudging and pricing strategies. It might be that certain characteristics lead to adverse effects, but this is not plausible, and the observed negative effects were small and statistically non-significant and may be explained by chance findings. Verification of these findings is needed in real-world trials based on larger sample sizes and with the use of more comprehensive interventions. TRIAL REGISTRATION: Dutch Trial Register ID NL7064, 30th of May, 2018, https://onderzoekmetmensen.nl/en/trial/20990.

Effects of increasing the availability of vegetarian options on main meal choices, meal offer satisfaction and liking: a pre-post analysis in a French university cafeteria.

BACKGROUND: Changing the food environment is an important public health lever for encouraging sustainable food choices. Targeting the availability of vegetarian main meals served in cafeterias substantially affects food choice, but acceptability has never been assessed. We examined the effects of an availability intervention at a French university cafeteria on students' main meal choices, meal offer satisfaction and liking. METHODS: A four-week controlled trial was conducted in a university cafeteria in Dijon, France. During the two-week control period, vegetarian main meals constituted 24% of the offer. In the subsequent two-week intervention period, this proportion increased to 48%, while all the other menu items remained unchanged. Students were not informed of the change. Student choices were tracked using production data, and daily paper ballots were used to assess student satisfaction with the meal offer and liking of the main meal they chose (score range [1;5]). Nutritional quality, environmental impact, and cost of production of meal choices were calculated for each lunchtime. Food waste was measured over 4 lunchtimes during control and intervention periods. An online questionnaire collected student feedback at the end of the study. RESULTS: Doubling availability of vegetarian main meals significantly increased the likelihood of choosing vegetarian options (OR = 2.57, 95% CI = [2.41; 2.74]). Responses of the paper ballots (n = 18,342) indicated slight improvements in meal offer satisfaction from 4.05 ± 0.92 to 4.07 ± 0.93 (p = 0.028) and in liking from 4.09 ± 0.90 to 4.13 ± 0.92 (p < 0.001) during control and intervention periods, respectively. The end-of-study questionnaire (n = 510) revealed that only 6% of students noticed a change the availability of vegetarian main meals. The intervention led to a decrease in the environmental impact of the main meals chosen, a slight decrease in nutritional quality, a slight increase in meal costs and no change in food waste. CONCLUSIONS: Doubling availability of vegetarian main meals in a university cafeteria resulted in a twofold increase in their selection, with students reporting being more satisfied and liking the main meals more during the intervention period. These results suggest that serving an equal proportion of vegetarian and nonvegetarian main meals could be considered in French university cafeterias to tackle environmental issues. TRIAL REGISTRATION: Study protocol and analysis plan were pre-registered on the Open Science Framework ( https://osf.io/pf3x7/ ).

Changing the food environment in secondary school canteens to promote healthy dietary choices: a qualitative study with school caterers.

BACKGROUND: Typical adolescent diets do not meet current dietary recommendations. There is a need to address these dietary patterns to reduce the risk of obesity and other diet-related diseases. Schools provide an opportune setting to do so, as students consume a substantial proportion of their daily dietary intake whilst at school. There is a developing evidence base on the use of choice architecture (food choice cues) to promote healthy eating in school contexts. It is necessary to understand the acceptability and feasibility of implementing such interventions. We aimed to explore these factors from the perspectives of secondary school caterers. METHODS: We conducted qualitative interviews with caterers from secondary schools across the West Midlands, UK and national/regional catering representatives. A semi-structured topic guide and visual aid were used to guide interviews. Interviews were recorded and transcribed. Framework analysis was conducted in NVivo v12. RESULTS: Twelve participants took part. Seven themes were identified and grouped into three categories: Acceptability (Suitability; Salient cues; Student engagement), Barriers (Catering decision drivers; Limits of influence), and Enablers (Perceived role; Opportunities). Caterers considered healthy food cues to be suited to adolescents as they require minimal reflective motivation. Salient cues included enhancing the placement, presentation and portability of healthy items, improving the dining environment and focusing pricing/incentive strategies on increased quantity. Student engagement was considered important. Some catering decision drivers conflicted with healthy food cues, and many felt that their role in healthy eating was limited due to the overwhelming influence of external food environments, adolescent resistance, and features of the secondary school canteen setting e.g. short duration of lunchtime, lack of space. However, caterers appeared motivated to implement healthy food cues and identified key opportunities for implementation, including integration into whole-school approaches to healthy eating. CONCLUSIONS: Interventions using healthy food cues appeared acceptable to secondary school caterers, key potential implementers of these strategies. Future interventions could incorporate strategies relating to placement, presentation and pricing to prompt healthy selections, and actions to engage the student body and improve the dining environment. Evaluations should consider potential impacts upon food purchasing, consumption and waste to address caterers' concerns about these issues.

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.

Changing the availability and positioning of more vs. less environmentally sustainable products: A randomised controlled trial in an online experimental supermarket.

Food purchasing behaviours are shaped by the choices available to shoppers and the way they are offered for sale. This study tested whether prominent positioning of more sustainable food items online and increasing their relative availability might reduce the environmental impact of foods selected in a 2x2 (availability x position) factorial randomised controlled trial. Participants (n = 1179) selected items in a shopping task in an experimental online supermarket. The availability intervention added lower-impact products to the regular range. The positioning intervention biased product order to give prominence to lower-impact products. The primary outcome was the environmental impact score (ranging from 1 "least impact" to 5 "most impact", of each item in shopping baskets) analysed using Welch's ANOVA. Secondary outcomes included interactions (analysed via linear regression) by gender, age group, education, income and meat consumption and we assessed intervention acceptability (using different frames) in a post-experiment questionnaire. Compared to control (mean = 21.6), mean eco quintile score was significantly reduced when availability & order was altered (-2.30; 95%CI: 3.04; -1.56) and when order only was changed (-1.67; 95%CI: 2.42; -0.92). No significant difference between availability only (-0.02; 95%CI: 0.73; 0.69) and control was found. There were no significant interactions between interventions or by demographic characteristics. Both interventions were acceptable under certain frames (positioning emphasising lower-impact products: 70.3% support; increasing lower-impact items: 74.3% support). Prominent positioning of more sustainable products may be an effective strategy to encourage more sustainable food purchasing. Increasing availability of more sustainable products alone did not significantly alter the environment impact of products selected.

Nudging plant-based alternatives to meat and dairy in a real-life online supermarket: A randomized controlled trial.

A shift from predominantly animal-based to plant-based consumption can benefit both planetary and public health. Nudging may help to promote such a shift. This study investigated nudge effects on plant-based alternatives to meat and dairy in an online supermarket. We conducted a two-arm, parallel-group, randomized controlled real-life online supermarket trial. Each customer transaction was randomized to a control arm (regular online supermarket) or an intervention arm (addition of placement, hedonic property and dynamic social norm nudges promoting meat and dairy alternatives). Outcomes were the aggregate of meat and dairy alternative purchases (primary outcome), the number of meat purchases, dairy purchases, meat alternative purchases, and dairy alternative purchases (secondary), and retailer revenue (tertiary). Generalized linear mixed models with a Conway-Maxwell Poisson distribution were used to estimate incidence rate ratios (IRRs). Analyzed data included 8488 transactions by participants (n = 4,266 control arm, n = 4,222 intervention arm), out of which 2,411 (66%) were aged above 45 years, 5,660 (67%) were females, and 1,970 (23%) lived in socially disadvantaged neighborhoods. Intervention arm participants purchased 10% (IRR 1.10 (95% CI 0.99-1.23)) more meat and dairy alternatives and 16% (1.16 (0.99-1.36)) more meat alternatives than control arm participants, although these findings are not statistically significant. There was no difference in dairy alternative purchases (1.00 (0.90-1.10)). Intervention arm participants purchased 3% less meats (0.97 (0.93-1.02)) and 2% less dairy products (0.98 (0.95-1.02)) than control participants. Retailer revenue was not affected (0.98 (0.95-1.01)). Online nudging strategies alone did not lead to a statistically significant higher amount of plant-based purchases, but replication of this work is needed with increased study power. Future studies should also consider nudging strategies as part of a broader set of policies to promote plant-based purchases. TRIAL REGISTRATION: Prospectively registered on 14th of May 2022. ISRCTN16569242 (https://doi.org/10.1186/ISRCTN16569242).

Health care providers acceptance of default prescribing of TB preventive treatment for people living with HIV in Malawi: a qualitative study.

BACKGROUND: Tuberculosis (TB) preventive treatment (TPT) substantially reduces the risk of developing active TB for people living with HIV (PLHIV). We utilized a novel implementation strategy based on choice architecture (CAT) which makes TPT prescribing the default option. Through CAT, health care workers (HCWs) need to "opt-out" when choosing not to prescribe TPT to PLHIV. We assessed the prospective, concurrent, and retrospective acceptability of TPT prescribing among HCWs in Malawi who worked in clinics participating in a cluster randomized trial of the CAT intervention. METHODS: 28 in-depth semi-structured interviews were conducted with HCWs from control (standard prescribing approach) and intervention (CAT approach) clinics. The CAT approach was facilitated in intervention clinics using a default prescribing module built into the point-of-care HIV Electronic Medical Record (EMR) system. An interview guide for the qualitative CAT assessment was developed based on the theoretical framework of acceptability and on the normalization process theory. Thematic analysis was used to code the data, using NVivo 12 software. RESULTS: We identified eight themes belonging to the three chronological constructs of acceptability. HCWs expressed no tension for changing the standard approach to TPT prescribing (prospective acceptability); however, those exposed to CAT described several advantages, including that it served as a reminder to prescribe TPT and routinized TPT prescribing (concurrent acceptability). Some felt that CAT may reduce HCW´s autonomy and might lead to inappropriate TPT prescribing (retrospective acceptability). CONCLUSIONS: The default prescribing module for TPT has now been incorporated into the point-of-care EMR system nationally in Malawi. This seems to fit the acceptability of the HCWs. Moving forward, it is important to train HCWs on how the EMR can be leveraged to determine who is eligible for TPT and who is not, while acknowledging the autonomy of HCWs.

Nudging food choice in a prison setting: an investigation using food choice data.

BACKGROUND: The prison population presents complex health needs and is disproportionately affected by poor health, compared to the general population. Diet has a clear role in prisoner health, and the prison food environment within which food choices are made is relatively under-researched. The aim of this study was to examine whether food choices in a women's prison changed after the introduction of a new menu design by the catering team. METHODS: The adjusted menu design incorporated an emoticon (a smiley face) placed next to designated 'Healthy Choice' foods on the menu sheets, which were used to preselect meals. Data comprised all women's (n = 865) food choices (more than 115,000 selections) for a period of 8 weeks (with the new menu) as well as 8 weeks prior (baseline period). The study design was a pre-post intervention study, and food selection was examined using chi-square tests and binary logistic regression models. RESULTS: The selection of promoted foods overall significantly increased under the new menu design (with the emoticon nudge strategy) compared to baseline; the effect size, however, was small according to the usual guidelines (21.4% compared to 20% at baseline; χ2 (1) = 32.6, p < 0.001, φ = 0.02). Individuals were 11% more likely (p < 0.001) to select the promoted 'Healthy Choice' foods under the adjusted food choice architecture. A significant effect was found for lunch and evening meal - but not for desserts. A minority of individual food items that were promoted had significant positive changes in selection, and were 1.3-4 times as likely to be selected when emoticons had been introduced, compared to baseline. CONCLUSIONS: Further research is needed to examine the potential added benefit of multiple complementary nudge strategies, and the relevance of the preselection of foods in advance of consumption.

Opt-out choice framing attenuates gender differences in the decision to compete in the laboratory and in the field.

Research shows that women are less likely to enter competitions than men. This disparity may translate into a gender imbalance in holding leadership positions or ascending in organizations. We provide both laboratory and field experimental evidence that this difference can be attenuated with a default nudge-changing the choice to enter a competitive task from a default in which applicants must actively choose to compete to a default in which applicants are automatically enrolled in competition but can choose to opt out. Changing the default affects the perception of prevailing social norms about gender and competition as well as perceptions of the performance or ability threshold at which to apply. We do not find associated negative effects for performance or wellbeing. These results suggest that organizations could make use of opt-out promotion schemes to reduce the gender gap in competition and support the ascension of women to leadership positions.

Reason Defaults: Presenting Defaults With Reasons for Choosing Each Option Helps Decision-Makers With Minority Interests.

Defaults are powerful tools for nudging individuals toward potentially beneficial options. However, defaults typically guide all decision-makers toward the same option and, consequently, may misguide individuals with minority interests. We test whether presenting defaults with information about heterogeneity can help individuals with minority interests select alternative options, and we dub this intervention a "reason default." Reason defaults preselect the option that is best for most individuals (like standard defaults) but also explain (a) why the default was selected and (b) who should opt for an alternative. In five preregistered studies using online convenience samples of adults (N = 4,210), we find that reason defaults can improve decision-makers' outcomes over standard defaults and forced choices by guiding most individuals toward the default option while helping individuals with minority interests select an alternative. Further, participants reported that reason defaults enhance transparency, decision ease, and understanding of the choice relative to standard defaults and forced choices.

Nudging interventions to improve children's sleep, physical activity and sedentary behavior: A scoping review.

In recent years, nudges to improve health behaviors have generated growing public health interest, as a promising and inexpensive intervention approach. Most nudging intervention reviews have examined nudges targeting adults, with few focusing on children. We aimed to review the literature on nudges designed to improve children's sedentary behaviors, physical activity, and sleep, and to identify existing gaps in scientific knowledge. We screened the literature for experimental and quasi-experimental studies written in French or English reporting on nudging interventions designed to improve physical activity, sedentary or sleep behavior in children aged 2-12. No setting restrictions were applied. Data extracted included setting, population, health behavior and method of measurement (reported vs measured or observed). The search was performed in June 2021 and yielded 3768 results, of which 17 articles met inclusion criteria. Most included studies aimed to improve physical activity, seven targeted sedentary behavior and only one was directed at sleep. Home or school settings were the most common. Most studies were RCTs, reported a positive effect and presented multicomponent interventions, including both nudges and non-nudge aspects. Interventions targeting the decision structure were the least represented type of nudges among our sample. Our results show a paucity of research investigating nudges aimed at improving pediatric physical activity, sedentary behavior, and sleep. Interventions using nudges alone were even fewer, highlighting the need to study this promising type of intervention to improve lifestyle behaviors of children.

Effectiveness of Behavioural Economics Informed Interventions for the Prevention, Screening, and Antiretroviral Treatment of HIV Infection: A Systematic Review of Randomized Controlled Trials.

Failure to meet international targets set for the human immunodeficiency virus HIV pandemic suggests that more effective public health strategies are needed. New strategies informed by behavioural economics are now increasingly being tested, with promising results. However, the evidence base is diverse and challenging for policymakers to interpret. This paper aims to synthesise existing evidence by reporting results from a systematic review of behavioural economics-based interventions for addressing HIV prevention, testing and treatment. The reported study was a systematic review of randomized controlled trials. The search was conducted in four electronic medical literature databases, six trial registries, four grey literature sources and was not restricted to any country or region. Bias was assessed using criteria outlined in the Cochrane Handbook for Systematic Reviews; quality of evidence was assessed using GRADE methodology. Fifteen full text articles were included in the final analysis. The synthesis of these studies revealed that strategies involving opt-out defaults, active-choice defaults, and lottery incentives can potentially increase uptake of HIV testing. Lottery incentives also showed signs of effectiveness in improving HIV prevention, ART adherence and initiation. Despite the promising findings, the overall evidence was judged to be of moderate to very low quality. Behavioural economics-based interventions are promising behavioural change strategies, although more well-designed studies are needed to strengthen the evidence base.

Choice architecture interventions promoting sustained healthier food choice and consumption by students in a secondary school setting: a systematic review of intervention studies.

OBJECTIVE: To systematically review the impact of choice architecture interventions (CAI) on the food choice of healthy adolescents in a secondary school setting. Factors potentially contributing to the effectiveness of CAI types and numbers implemented and its long-term success were examined. DESIGN: PUBMED and Web of Science were systematically searched in October 2021. Publications were included following predefined inclusion criteria and grouped according to the number and duration of implemented interventions. Intervention impact was determined by a systematic description of the reported quantitative changes in food choice and/or consumption. Intervention types were compared with regard to food selection and sustained effects either during or following the intervention. SETTING: CAI on food choice of healthy adolescents in secondary schools. PARTICIPANTS: Not applicable. RESULTS: Fourteen studies were included; four randomised controlled trials and five each of controlled or uncontrolled pre-post design, respectively. Four studies implemented a single CAI type, with ten implementing > 1. Three studies investigated CAI effects over the course of a school year either by continuous or repeated data collection, while ten studies' schools were visited on selected days during an intervention. Twelve studies reported desired changes in overall food selection, yet effects were not always significant and appeared less conclusive for longer-term studies. CONCLUSIONS: This review found promising evidence that CAI can be effective in encouraging favourable food choices in healthy adolescents in a secondary school setting. However, further studies designed to evaluate complex interventions are needed.

Acceptability of workplace choice architecture modification for healthy behaviours.

BACKGROUND: Altering the choice architecture of decision contexts can assist behaviour change, but the acceptability of this approach has sparked debate. Considering hypothetical interventions, people generally welcome the approach for promoting health, but little evidence exists on acceptance in the real world. Furthermore, research has yet to explore the implementers' perspective, acknowledging the multidimensionality of the acceptability construct. Addressing these knowledge gaps, this study evaluated the acceptability of a quasi-experimental implementation-effectiveness trial that modified the worksite choice architecture for healthy eating and daily physical activity. METHODS: Fifty-three worksites participated in the 12-month intervention and implemented altogether 23 choice architecture strategies (Mdn 3/site), including point-of-choice prompts and changes to choice availability or accessibility. Retrospective acceptability evaluation built on deductive qualitative content analysis of implementer interviews (n = 65) and quantitative analysis of an employee questionnaire (n = 1124). Qualitative analysis examined implementers' thoughts and observations of the intervention and its implementation, considering six domains of the Theoretical Framework of Acceptability: ethicality, affective attitude, burden, intervention coherence, opportunity costs, and perceived effectiveness. Quantitative analysis examined employees' acceptance (7-point Likert scale) of eight specific intervention strategies using Friedman test and mixed-effects logistic regression. RESULTS: Implementers considered the choice architecture approach ethical for workplace health promotion, reported mostly positive affective attitudes to and little burden because of the intervention. Intervention coherence supported acceptance through increased interest in implementation, whereas low perceived utility and high intensity of implementation reduced cost acceptance. Perceived effectiveness was mixed and varied along factors related to the implementer, social/physical work environment, employer, and employee. Employees showed overall high acceptance of evaluated strategies (Mdn 7, IQR 6.4-7), though strategies replacing unhealthy foods with healthier alternatives appeared less supported than providing information or enhancing healthy option availability or accessibility (p-values < 0.02). Greater proportion of male employees per site predicted lower overall acceptance (OR 4.4, 95% CI 1.2-16.5). CONCLUSIONS: Work communities appear to approve workplace choice architecture interventions for healthy eating and physical activity, but numerous factors influence acceptance and warrant consideration in future interventions. The study contributes with a theory-based, multidimensional evaluation that considered the perspectives of implementers and influenced individuals across heterogeneous real-world settings.

The negative impact of vegetarian and vegan labels: Results from randomized controlled experiments with US consumers.

Reducing consumption of animal products is a critically important challenge in efforts to mitigate the climate crisis. Despite this, meals containing animal products are often presented as the default versus more environmentally sustainable vegetarian or vegan options. We tested whether vegetarian and vegan labels on menu items negatively impact the likelihood of US consumers choosing these items by using a between-subjects experimental design, where participants chose a preference between two items. Menu items were presented with titles and descriptions typical at restaurants, and a random group saw "vegan" or "vegetarian" labels in the titles of one of the two items. Two field studies were conducted at a US academic institution, where people selected what to eat via event registration forms. The methodology was extended to an online study, where US consumers selected what to hypothetically eat in a series of choice questions. Overall, results showed the menu items were significantly less likely to be chosen when they were labeled, with much larger effects in the field studies, where choice was not hypothetical. In addition, the online study showed male participants had a significantly higher preference for options containing meat versus other participants. Results did not indicate the impact of labels differed by gender. Furthermore, this study did not find that vegetarians and vegans were more likely to choose items with meat when the labels were removed, indicating that removing labels did not negatively impact them. The results suggest removing vegetarian and vegan labels from menus could help guide US consumers towards reduced consumption of animal products.