Economic evaluation of price discounts and skill-building strategies on purchase and consumption of healthy food and beverages: The SHELf randomized controlled trial

Real-life experiments in supermarkets to encourage healthy dietary-related behaviours: opportunities, challenges and lessons learned

BACKGROUND

Supermarkets are the primary source of food for many people yet their full potential as a setting to encourage healthy dietary-related behaviours remains underutilised. Sharing the experiences from research groups who have worked with supermarket chains to evaluate strategies that promote healthy eating could improve the efficiency of building such relationships and enhance the design quality of future research studies.

METHODS

A collective case study approach was used to synthesise experiences of engaging and sustaining research collaborations with national supermarket chains to test the effectiveness of health-focused in-store interventions. The collective narrative covers studies conducted in three high-income countries: Australia, the Netherlands and the United Kingdom.

RESULTS

We have distilled our experiences and lessons learned into six recommendations for conducting high quality public health research with commercial supermarket chains. These include: (i) using personal contacts, knowledge of supermarket activities and engaging executive management to establish a partnership and allowing time to build trust; (ii) using scientifically robust study designs with appropriate sample size calculations; (iii) formalising data exchange arrangements and allocating adequate resource for data extraction and re-categorisation; (iv) assessing effects at individual/households level where possible; (v) designing a mixed-methods process evaluation to measure intervention fidelity, dose and unintended consequences; and (vi) ensuring scientific independence through formal contract agreements.

CONCLUSIONS

Our collective experiences of working in non-financial partnerships with national supermarket chains could be useful for other research groups looking to develop and implement supermarket studies in an efficient manner. Further evidence from real-life supermarket interventions is necessary to identify sustainable strategies that can improve population diet and maintain necessary commercial outcomes.

Cost-Benefit and Cost-Utility Analyses to Demonstrate the Potential Value-for-Money of Supermarket Shelf Tags Promoting Healthier Packaged Products in Australia

The supermarket environment impacts the healthiness of food purchased and consumed. Shelf tags that alert customers to healthier packaged products can improve the healthiness of overall purchases. This study assessed the potential value-for-money of implementing a three-year shelf tag intervention across all major supermarket chains in Australia. Cost-benefit analyses (CBA) and cost-utility analyses (CUA) were conducted based on results of a 12-week non-randomised controlled trial of a shelf tag intervention in seven Australian supermarkets. The change in energy density of all packaged foods purchased during the trial was used to estimate population-level changes in mean daily energy intake. A multi-state, multiple-cohort Markov model estimated the subsequent obesity-related health and healthcare cost outcomes over the lifetime of the 2019 Australian population. The CBA and CUA took societal and healthcare sector perspectives, respectively. The intervention was estimated to produce a mean reduction in population body weight of 1.09 kg. The net present value of the intervention was approximately AUD 17 billion (B). Over 98% of the intervention costs were borne by supermarkets. CUA findings were consistent with the CBA-the intervention was dominant, producing both health benefits and cost-savings. Shelf tags are likely to offer excellent value-for-money from societal and healthcare sector perspectives.

A systematic review of supermarket automated electronic sales data for population dietary surveillance

Context

Most dietary assessment methods are limited by self-report biases, how long they take for participants to complete, and cost of time for dietitians to extract content. Electronically recorded, supermarket-obtained transactions are an objective measure of food purchases, with reduced bias and improved timeliness and scale.

Objective

The use, breadth, context, and utility of electronic purchase records for dietary research is assessed and discussed in this systematic review.

Data sources

Four electronic databases (MEDLINE, EMBASE, PsycINFO, Global Health) were searched. Included studies used electronically recorded supermarket transactions to investigate the diet of healthy, free-living adults.

Data extraction

Searches identified 3422 articles, of which 145 full texts were retrieved and 72 met inclusion criteria. Study quality was assessed using the National Institutes of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies.

Data analysis

Purchase records were used in observational studies, policy evaluations, and experimental designs. Nutrition outcomes included dietary patterns, nutrients, and food category sales. Transactions were linked to nutrient data from retailers, commercial data sources, and national food composition databases.

Conclusion

Electronic sales data have the potential to transform dietary assessment and worldwide understanding of dietary behavior. Validation studies are warranted to understand limits to agreement and extrapolation to individual-level diets.

Systematic Review Registration

PROSPERO registration no. CRD42018103470

Helping parents provide vegetable snacks: Investigating price and taste as barriers

Snacks contribute nearly one-quarter of children's daily energy intake in the USA. Snack time therefore represents an opportunity for parents to provide foods with key nutrients. Instead, the most common snack foods are major contributors to children's consumption of added sugars and sodium. Parents face major barriers to providing healthier snacks, including perceptions of high cost and lack of child acceptance. We obtained both economic and qualitative data to inform and optimize interventions for parents to promote vegetable snacks for children. We conducted a survey with parents (n = 368) to estimate how much of a discount would influence vegetable snack purchases by estimating willingness-to-pay using the contingent valuation method, using baby-cut carrots as a sample product. We conducted three focus groups (n = 19) and 1 group interview (n = 2) with children to help understand how to increase the appeal of vegetable snacks. Most (70%) parents accepted the reference price for the vegetable snack. Among those who did not, contingent valuation analysis revealed that a mean discount of approximately 30% would shift consumers to purchasing the snack. Focus group results revealed that the appeal of vegetable snacks to children was influenced by how they were prepared and presented, and the child's familiarity with the vegetables and ability to choose among them. This study lays the groundwork for effective interventions to promote the provision of vegetable snacks by parents.

Economic evaluation of a farm-to-Special Supplemental Nutrition Programme for Women, Infants and Children intervention promoting vegetable consumption

OBJECTIVE

To evaluate the cost and cost-effectiveness of a farm-to-Special Supplemental Nutrition Programme for Women, Infants and Children (WIC) intervention to promote vegetable intake and the redemption of WIC vouchers for produce purchases at farmers' markets.

DESIGN

An economic analysis was undertaken using data from a pilot of the intervention. Vegetable intake was assessed with a reflection spectroscopy device (the Veggie Meter® [VM]) and via self-report. Voucher redemption was reported by WIC. Total and per participant intervention costs and cost-effectiveness ratios (expressed as cost per intervention effect) were estimated in 2019 US dollars over a 6-month period from the perspective of the agency implementing the intervention.

SETTING

A large, urban WIC agency.

PARTICIPANTS

Participants were 297 WIC-enrolled adults.

RESULTS

Post-intervention, VM scores, self-reported vegetable intake and voucher redemption were higher in the intervention as compared with the control study group. Over the 6-month period, intervention costs were $31 092 ($194 unit cost per participant). Relative to the control group, the intervention cost $8·10 per increased VM score per participant, $3·85 per increased cup/d of vegetables consumed per participant and $3·29 per increased percentage point in voucher redemption per participant.

CONCLUSIONS

Intervention costs and cost-effectiveness ratios compared favourably with those reported for other interventions targeting vegetable intake in low-income groups, suggesting that the programme may be cost effective in promoting vegetable purchases and consumption. As there is no benchmark against which to compare cost-effectiveness ratios expressed as cost per unit of effectiveness, conclusions regarding whether this is the case must await further research.

A Systematic Review of Economic Evaluations of Health-Promoting Food Retail-Based Interventions

BACKGROUND

While the number of retail interventions with impacts on diet- and/or health-related outcomes is increasing, the economic evaluation literature is limited. This review investigated (i) the cost-effectiveness of health-promoting food retail interventions and (ii) key assumptions adopted in these evaluations.

METHODS

A systematic review of published academic studies was undertaken (CRD42020153763). Fourteen databases were searched. Eligible studies were identified, analysed, and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines.

RESULTS

Eight studies that evaluated 30 retail interventions were included in the review. Common outcomes reported were cost per healthy food item purchased/served or cost per disability-adjusted life year (DALY) averted. Four studies undertook cost-utility analyses and half of these studies concluded that retail interventions were cost-effective in improving health outcomes. Most studies did not state any assumptions regarding compensatory behaviour (i.e., purchases/consumption of non-intervention foods or food purchases/consumption from non-intervention settings) and presumed that sales data were indicative of consumption.

CONCLUSION

The cost-effectiveness of retail-based health-promoting interventions is inconclusive. Future health-promoting retail interventions should regularly include an economic evaluation which addresses key assumptions related to compensatory behaviour and the use of sales data as a proxy for consumption.

Retail Nutrition Programs and Outcomes: An Evidence Analysis Center Scoping Review

As nutrition-related diseases contribute to rising health care costs, food retail settings are providing a unique opportunity for registered dietitian nutritionists (RDNs) to address the nutritional needs of consumers. Food as Medicine interventions play a role in preventing and/or managing many chronic conditions that drive health care costs. The objective of this scoping review was to identify and characterize literature examining Food as Medicine interventions within food retail settings and across consumer demographics. An electronic literature search of 8 databases identified 11,404 relevant articles. Results from the searches were screened against inclusion criteria, and intervention effectiveness was assessed for the following outcomes: improvement in health outcomes and cost-effectiveness. One-hundred and eighty-six papers and 25 systematic reviews met inclusion criteria. Five categories surfaced as single interventions: prescription programs, incentive programs, medically tailored nutrition, path-to-purchase marketing, and personalized nutrition education. Multiple combinations of intervention categories, reporting of health outcomes (nutritional quality of shopping purchases, eating habits, biometric measures), and cost-effectiveness (store sales, health care dollar savings) also emerged. The intervention categories that produced both improved health outcomes and cost-effectiveness included a combination of incentive programs, personalized nutrition education, and path-to-purchase marketing. Food as Medicine interventions in the food retail setting can aid consumers in navigating health through diet and nutrition by encompassing the following strategic focus areas: promotion of health and well-being, managing chronic disease, and improving food security. Food retailers should consider the target population and desired focus areas and should engage registered dietitian nutritionists when developing Food as Medicine interventions.

Population-based interventions addressing food insecurity in Australia: A systematic scoping review

AIM

Food insecurity (FI) is a critical public health issue in Australia. Population-based interventions aiming to address the socio-ecological determinants of FI are critical for relieving and preventing it. This review aimed to map and summarise the characteristics of population-based interventions addressing household and/or community FI in Australia.

METHODS

A systematic scoping review was undertaken. Five databases, selected for range and relevance to FI in Australia ("CINAHL plus", "Ovid MEDLINE", "Sociological Abstracts", "Australian Public Affairs Information Service", and "Rural and Remote Health") were searched in May 2018 using the terms and relevant synonyms "FI" and "interventions". In addition a systematic grey literature search using multiple Google searches was undertaken. Data synthesis included categorisation and counting intervention type. Interventions were defined and charted by influence of at least one dimension of food security and impact on the socioeconomic, cultural and environmental conditions.

RESULTS

A total of 3565 published and grey literature records were identified, with the final 60 records describing 98 interventions. Few national interventions were identified, with approaches predominantly in Victoria, Northern Territory and Tasmania. Determinants related to living and working environments, food availability and food utilisation were most frequently addressed. Interventions addressing the key determinant of FI economic access were limited. A number of interventions did not appear to be associated with rigorous evaluation.

CONCLUSIONS

While there is evidence of population responses to FI in Australia, the effectiveness of these remains limited. Importantly there is a lack of coordinated and coherent national responses that address the range of FI determinants.

Environmental interventions to reduce the consumption of sugar-sweetened beverages and their effects on health

BACKGROUND

Frequent consumption of excess amounts of sugar-sweetened beverages (SSB) is a risk factor for obesity, type 2 diabetes, cardiovascular disease and dental caries. Environmental interventions, i.e. interventions that alter the physical or social environment in which individuals make beverage choices, have been advocated as a means to reduce the consumption of SSB.

OBJECTIVES

To assess the effects of environmental interventions (excluding taxation) on the consumption of sugar-sweetened beverages and sugar-sweetened milk, diet-related anthropometric measures and health outcomes, and on any reported unintended consequences or adverse outcomes.

SEARCH METHODS

We searched 11 general, specialist and regional databases from inception to 24 January 2018. We also searched trial registers, reference lists and citations, scanned websites of relevant organisations, and contacted study authors.

SELECTION CRITERIA

We included studies on interventions implemented at an environmental level, reporting effects on direct or indirect measures of SSB intake, diet-related anthropometric measures and health outcomes, or any reported adverse outcome. We included randomised controlled trials (RCTs), non-randomised controlled trials (NRCTs), controlled before-after (CBA) and interrupted-time-series (ITS) studies, implemented in real-world settings with a combined length of intervention and follow-up of at least 12 weeks and at least 20 individuals in each of the intervention and control groups. We excluded studies in which participants were administered SSB as part of clinical trials, and multicomponent interventions which did not report SSB-specific outcome data. We excluded studies on the taxation of SSB, as these are the subject of a separate Cochrane Review.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened studies for inclusion, extracted data and assessed the risks of bias of included studies. We classified interventions according to the NOURISHING framework, and synthesised results narratively and conducted meta-analyses for two outcomes relating to two intervention types. We assessed our confidence in the certainty of effect estimates with the GRADE framework as very low, low, moderate or high, and presented 'Summary of findings' tables.

MAIN RESULTS

We identified 14,488 unique records, and assessed 1030 in full text for eligibility. We found 58 studies meeting our inclusion criteria, including 22 RCTs, 3 NRCTs, 14 CBA studies, and 19 ITS studies, with a total of 1,180,096 participants. The median length of follow-up was 10 months. The studies included children, teenagers and adults, and were implemented in a variety of settings, including schools, retailing and food service establishments. We judged most studies to be at high or unclear risk of bias in at least one domain, and most studies used non-randomised designs. The studies examine a broad range of interventions, and we present results for these separately.Labelling interventions (8 studies): We found moderate-certainty evidence that traffic-light labelling is associated with decreasing sales of SSBs, and low-certainty evidence that nutritional rating score labelling is associated with decreasing sales of SSBs. For menu-board calorie labelling reported effects on SSB sales varied.Nutrition standards in public institutions (16 studies): We found low-certainty evidence that reduced availability of SSBs in schools is associated with decreased SSB consumption. We found very low-certainty evidence that improved availability of drinking water in schools and school fruit programmes are associated with decreased SSB consumption. Reported associations between improved availability of drinking water in schools and student body weight varied.Economic tools (7 studies): We found moderate-certainty evidence that price increases on SSBs are associated with decreasing SSB sales. For price discounts on low-calorie beverages reported effects on SSB sales varied.Whole food supply interventions (3 studies): Reported associations between voluntary industry initiatives to improve the whole food supply and SSB sales varied.Retail and food service interventions (7 studies): We found low-certainty evidence that healthier default beverages in children's menus in chain restaurants are associated with decreasing SSB sales, and moderate-certainty evidence that in-store promotion of healthier beverages in supermarkets is associated with decreasing SSB sales. We found very low-certainty evidence that urban planning restrictions on new fast-food restaurants and restrictions on the number of stores selling SSBs in remote communities are associated with decreasing SSB sales. Reported associations between promotion of healthier beverages in vending machines and SSB intake or sales varied.Intersectoral approaches (8 studies): We found moderate-certainty evidence that government food benefit programmes with restrictions on purchasing SSBs are associated with decreased SSB intake. For unrestricted food benefit programmes reported effects varied. We found moderate-certainty evidence that multicomponent community campaigns focused on SSBs are associated with decreasing SSB sales. Reported associations between trade and investment liberalisation and SSB sales varied.Home-based interventions (7 studies): We found moderate-certainty evidence that improved availability of low-calorie beverages in the home environment is associated with decreased SSB intake, and high-certainty evidence that it is associated with decreased body weight among adolescents with overweight or obesity and a high baseline consumption of SSBs.Adverse outcomes reported by studies, which may occur in some circumstances, included negative effects on revenue, compensatory SSB consumption outside school when the availability of SSBs in schools is reduced, reduced milk intake, stakeholder discontent, and increased total energy content of grocery purchases with price discounts on low-calorie beverages, among others. The certainty of evidence on adverse outcomes was low to very low for most outcomes.We analysed interventions targeting sugar-sweetened milk separately, and found low- to moderate-certainty evidence that emoticon labelling and small prizes for the selection of healthier beverages in elementary school cafeterias are associated with decreased consumption of sugar-sweetened milk. We found low-certainty evidence that improved placement of plain milk in school cafeterias is not associated with decreasing sugar-sweetened milk consumption.

AUTHORS' CONCLUSIONS

The evidence included in this review indicates that effective, scalable interventions addressing SSB consumption at a population level exist. Implementation should be accompanied by high-quality evaluations using appropriate study designs, with a particular focus on the long-term effects of approaches suitable for large-scale implementation.

What is known about consumer nutrition environments in Australia? A scoping review of the literature

OBJECTIVE

Food environments can influence food selection and hold the potential to reduce obesity, non-communicable diseases and their inequalities. 'Consumer nutrition environments' describe what consumers encounter within a food retail outlet, including products, price, promotion and placement. This study aimed to summarize the attributes that have been examined in existing peer-reviewed studies of Australian consumer nutrition environments, identify knowledge gaps and provide recommendations for future research.

METHODS

A systematic search of peer-reviewed literature was conducted. Sixty-six studies that assessed an aspect of within-store consumer nutrition environments were included.

RESULTS

Most studies were published from 2011 onwards and were conducted in capital cities and in supermarkets. Studies assessed the domains of product (40/66), price (26/66), promotion (16/66) and placement (6/66). The most common research themes identified were assessment of the impact of area socioeconomic status (13/66), remoteness (9/66) and food outlet type (7/66) on healthy food prices; change in price of healthy foods (6/66); variety of healthy foods (5/66); and prevalence of unhealthy child-orientated products (5/66).

CONCLUSIONS

This scoping review identified a large number of knowledge gaps. Recommended priorities for researchers are as follows: (1) develop consistent observational methodology, (2) consider consumer nutrition environments in rural and remote communities, (3) develop an understanding of food service outlets, (4) build on existing evidence in all four domains of product, price, placement and promotion and (5) determine effective policy and store-based interventions to increase healthy food selection.

Facilitators and barriers to modifying dietary and hygiene behaviours as adjuvant treatment in patients with depression in primary care: a qualitative study

BACKGROUND

Major depression is a highly prevalent condition. Its pathogenesis is related to a wide variety of biological and psychosocial factors and among these is factors related to lifestyle. Lifestyle-based interventions seem to be appropriate strategies as coadjutant treatment. The objective of this study is to explore and identify expectations and experiences of both patients and healthcare professionals that can point to the main barriers and facilitators with regard to the promotion of healthy dietary and hygiene behaviours in patients suffering from major depression.

METHODS

A qualitative design was used to collect information from a wide range of purposefully and theoretically guided samples of depressed patients and health professionals from Primary Care (PC). Both in-depth interviews and discussion groups were used. A standardized protocol was designed to guide the interviews and groups, including the preparation of a topic list to be addressed, with previously tested, open suggestions that could be of interest. A thematic analysis was performed from grounded theory in order to explore, develop and define until saturation the emergent categories of analysis derived from the individual interview and group data.

RESULTS

Both patients as well as PC professionals noted a series of central aspects with respect to the implementation of a programme for the acquisition of healthy dietary and hygiene habits for depressive patients, which may be organized around 'personal', 'programmatic', and 'transversal' aspects. As for the personal aspects, categories regarding 'patient history', and 'disposition' were found; the programmatic aspects included categories such as 'presentation and monitoring', and modification of 'cognitive' and 'behavioural' habits; whereas the transversal aspects comprised the possibilities of 'social support' and defining categories of 'objectives'.

CONCLUSION

The implementation of intervention programmes that combine dietary and hygiene-related factors in patients with depression is complex, given the nature of the disorder itself, and its symptoms such as apathy and feelings of guilt or incompetence. Key issues exist for the success of the intervention, such as the simplicity of guidelines, tailoring through motivational interviewing, prolonged and intense monitoring throughout the different stages of the disorder, and the provision of adequate feedback and social support. PC could be an appropriate level in which to implement these interventions.

Pricing Strategies to Encourage Availability, Purchase, and Consumption of Healthy Foods and Beverages: A Systematic Review

Introduction

Food pricing policies to promote healthy diets, such as taxes, price manipulations, and food subsidies, have been tested in different settings. However, little consensus exists about the effect of these policies on the availability of healthy and unhealthy foods, on what foods consumers buy, or on the impact of food purchases on consumer health outcomes. We conducted a systematic review of studies of the effect of food-pricing interventions on retail sales and on consumer purchasing and consumption of healthy foods and beverages.

Methods

We used MEDLINE, Embase, PsycINFO, Web of Science, ClinicalTrials.gov, and the Cochrane Library to conduct a systematic search for peer-reviewed articles related to studies of food pricing policies. We selected articles that were published in English from January 2000 through December 2016 on the following types of studies: 1) real-world experimental studies (randomized controlled trials, quasi-experimental studies, and natural experiments); 2) population studies of people or retail stores in middle-income and high-income countries; 3) pricing interventions alone or in combination with other strategies (price promotions, coupons, taxes, or cash-back rebates), excluding studies of vending-machine or online sales; and 4) outcomes studies at the retail (stocking, sales) and consumer (purchasing, consumption) levels. We selected 65 articles representing 30 studies for review.

Results

Sixteen pricing intervention studies that sought to improve access to healthy food and beverage options reported increased stocking and sales of promoted food items. Most studies (n = 23) reported improvement in the purchasing and consumption of healthy foods or beverages or decreased purchasing and consumption of unhealthy foods or beverages. Most studies assessed promotions of fresh fruits and vegetables (n = 20); however, these foods may be hard to source, have high perishability, and raise concerns about safety and handling. Few of the pricing studies we reviewed discouraged purchasing and consumption of unhealthy foods (n = 6). Many studies we reviewed had limitations, including lack of formative research, process evaluation, or psychosocial and health assessments of the intervention’s impact; short intervention duration; or no assessment of food substitutions or the effects of pricing interventions on food purchasing and diets.

Conclusion

Pricing interventions generally increased stocking, sales, purchasing, and consumption of promoted foods and beverages. Additional studies are needed to differentiate the potential impact of selected pricing strategies and policies over others.

Effect of a price discount and consumer education strategy on food and beverage purchases in remote Indigenous Australia: a stepped-wedge randomised controlled trial

BACKGROUND

Evidence is mounting that price discounts can be effective in improving diet. This study examined the effectiveness of a 20% price discount on food and drink purchases with and without consumer education in remote Indigenous Australia.

METHODS

A 20% discount on fruit, vegetables, water, and artificially sweetened soft drinks was applied for 24 weeks in 20 communities in remote Indigenous Australia where the community store was managed by the Arnhem Land Progress Aboriginal Corporation (ALPA) or Outback Stores (OBS) in a stepped-wedge randomised trial. Communities were randomly allocated to a fixed framework of five sets of four stratified by store association; ten stores (two in each set) were randomly assigned to receive consumer education. A store from each of the ALPA and OBS store groups (contained in separate opaque envelopes) was selected, and stores in turn continued to be consecutively allocated to the fixed store set framework, starting with the first store slot in the first store set, until all stores had been allocated. The effect of the discount on the weight of fruit and vegetables purchased (the primary endpoint) was assessed using weekly store sales data and mixed models per protocol. We did sensitivity analyses by repeating the analyses with the outliers included and repeating the analyses for the primary outcome measure removing each store one at a time. This trial was registered with Australian New Zealand Clinical Trials Registry, number ACTRN12613000694718.

FINDINGS

Weekly store sales data on all food and drink products sold in 20 stores were collected from July 1, 2012, to Dec 28, 2014. Price discount alone was associated with a 12·7% (95% CI 4·1-22·1) increase in purchases in grams of fruit and vegetables combined (primary outcome), and a 19·8% (6·2-35·1) increase post discount (after vs before); an effect of 12 g and 18 g per capita per day. Sensitivity analyses did not modify the results for the primary outcome measure.

INTERPRETATION

A 20% discount can only increase fruit and vegetable purchases to help protect against obesity and diet related disease to a certain extent. Large discounts might have a greater impact than small discounts. Creative merchandising approaches to consumer education could also be considered alongside fiscal interventions to achieve marked improvements in diet.

FUNDING

Australian National Health and Medical Research Council.