The broader health benefits of optimised dietary thresholds proposed for type 2 diabetes prevention in Aotearoa New Zealand: simulation modelling.

AIM: Optimised dietary thresholds for type 2 diabetes prevention exist; however, they likely have additional benefits beyond diabetes prevention. We have modelled the effects of the proposed dietary thresholds on Health-Adjusted Life Years (HALY), health inequities and health system cost in Aotearoa New Zealand. METHODS: We created a national diet scenario using the optimised thresholds and compared it with current intakes using an established multistate life table. The primary model considered change in outcome from increasing intakes of fruits, vegetables, nuts and seeds while decreasing red meat and sugar-sweetened beverages. A separate secondary nutrient-based model considered change due to increasing whole grains and yoghurt while decreasing refined grains, potatoes and fruit juice. Both models considered the direct non-weight mediated associations between diet and disease. RESULTS: In the primary model, adopting the dietary thresholds produced clear benefit to Aotearoa New Zealand in terms of HALY (1.2 million years [95%UI 1.0-1.5]), and a health system cost saving of $17.9 billion (95%UI 13.6-23.2) over the population life course. HALY gain was at least 1.8 times higher for Maori than non-Maori. The secondary model indicated further gains in HALY for all population groups and health systems costs. CONCLUSION: These striking benefits of altering current dietary intakes provide strong evidence of the need for change. Such change requires government commitment to an overarching food strategy in Aotearoa New Zealand to build supportive food environments that enable healthy choices at affordable prices.

Dietary sources of sodium across the diverse New Zealand adult population.

Our aim was to determine dietary sources of sodium for adults in Aotearoa New Zealand (NZ). We used data from the most recent NZ Adult Nutrition Survey (ANS 2008/09) including 4,721 free-living adults aged 15+ years who completed a single 24-hour dietary recall. Population weighted percentage contribution to dietary sodium was calculated and ranked for major and minor food categories across the total population and by gender (male and female), ethnicity (Maori, Pacific, Asian, and Other), and age (15 to 20, 21 to 40, 41 to 60, and 61+ years). Fifteen major food categories contributed ∼80% of sodium consumed by the total population; the top five were 'Bread' (18%), 'Bread-based dishes' (11%), 'Grains and pasta' (7%), 'Pork' (7%), and 'Sausages and processed meats' (5%). Compared to other sub-groups within the same demographic, the top-five major sources of sodium specific to Females were 'Soups and stocks', Pacific communities were Poultry, Maori whanau was 'Pork', Others was 'Pork', Asian was 'Soups and stocks' and 'Vegetables', and 61+ years was 'Soups and stocks'. Our findings provide information on the major and minor food sources of sodium for the diverse NZ population. The differences observed in major dietary sources by population subgroup are critical for policymakers to include in the development of any future country-specific sodium reduction targets; repeating the total population approach taken in several other countries is unlikely to improve inquities in heart-related health in NZ.

Fuelling walking and cycling: human powered locomotion is associated with non-negligible greenhouse gas emissions.

Reducing motorized transport and increasing active transport (i.e. transport by walking, cycling and other active modes) may reduce greenhouse gas (GHG) emissions and improve health. But, active modes of transport are not zero emitters. We aimed to quantify GHG emissions from food production required to fuel extra physical activity for walking and cycling. We estimate the emissions (in kgCO2e) per kilometre travelled for walking and cycling from energy intake required to compensate for increased energy expenditure, and data on food-related GHG emissions. We assume that persons who shift from passive modes of transport (e.g. driving) have increased energy expenditure that may be compensated with increased food consumption. The GHG emissions associated with food intake required to fuel a kilometre of walking range between 0.05 kgCO2e/km in the least economically developed countries to 0.26 kgCO2e/km in the most economically developed countries. Emissions for cycling are approximately half those of walking. Emissions from food required for walking and cycling are not negligible in economically developed countries which have high dietary-related emissions. There is high uncertainty about the actual emissions associated with walking and cycling, and high variability based on country economic development. Our study highlights the need to consider emissions from other sectors when estimating net-emissions impacts from transport interventions.

Health Gain, Cost Impacts, and Cost-Effectiveness of a Mass Media Campaign to Promote Smartphone Apps for Physical Activity: Modeling Study.

BACKGROUND: Physical activity smartphone apps are a promising strategy to increase population physical activity, but it is unclear whether government mass media campaigns to promote these apps would be a cost-effective use of public funds. OBJECTIVE: We aimed to estimate the health impacts, costs, and cost-effectiveness of a one-off national mass media campaign to promote the use of physical activity apps. METHODS: We used an established multistate life table model to estimate the lifetime health gains (in quality-adjusted life years [QALYs]) that would accrue if New Zealand adults were exposed to a one-off national mass media campaign to promote physical activity app use, with a 1-year impact on physical activity, compared to business-as-usual. A health-system perspective was used to assess cost-effectiveness. and a 3% discount rate was applied to future health gains and health system costs. RESULTS: The modeled intervention resulted in 28 QALYs (95% uncertainty interval [UI] 8-72) gained at a cost of NZ $81,000/QALY (2018 US $59,500; 95% UI 17,000-345,000), over the remaining life course of the 2011 New Zealand population. The intervention had a low probability (20%) of being cost-effective at a cost-effectiveness threshold of NZ $45,000 (US $32,900) per QALY. The health impact and cost-effectiveness of the intervention were highly sensitive to assumptions around the maintenance of physical activity behaviors beyond the duration of the intervention. CONCLUSIONS: A mass media campaign to promote smartphone apps for physical activity is unlikely to generate much health gain or be cost-effective at the population level. Other investments to promote physical activity, particularly those that result in sustained behavior change, are likely to have greater health impacts.

Health benefits and costs of weight-loss dietary counselling by nurses in primary care: a cost-effectiveness analysis.

OBJECTIVE: We aimed to estimate the cost-effectiveness of brief weight-loss counselling by dietitian-trained practice nurses, in a high-income-country case study. DESIGN: A literature search of the impact of dietary counselling on BMI was performed to source the 'best' effect size for use in modelling. This was combined with multiple other input parameters (e.g. epidemiological and cost parameters for obesity-related diseases, likely uptake of counselling) in an established multistate life-table model with fourteen parallel BMI-related disease life tables using a 3 % discount rate. SETTING: New Zealand (NZ). PARTICIPANTS: We calculated quality-adjusted life-years (QALY) gained and health-system costs over the remainder of the lifespan of the NZ population alive in 2011 (n 4·4 million). RESULTS: Counselling was estimated to result in an increase of 250 QALY (95 % uncertainty interval -70, 560 QALY) over the population's lifetime. The incremental cost-effectiveness ratio was 2011 $NZ 138 200 per QALY gained (2018 $US 102 700). Per capita QALY gains were higher for Maori (Indigenous population) than for non-Maori, but were still not cost-effective. If willingness-to-pay was set to the level of gross domestic product per capita per QALY gained (i.e. 2011 $NZ 45 000 or 2018 $US 33 400), the probability that the intervention would be cost-effective was 2 %. CONCLUSIONS: The study provides modelling-level evidence that brief dietary counselling for weight loss in primary care generates relatively small health gains at the population level and is unlikely to be cost-effective.

Achieving Healthy and Sustainable Diets: A Review of the Results of Recent Mathematical Optimization Studies.

Climate protection and other environmental concerns render it critical that diets and agriculture systems become more sustainable. Mathematical optimization techniques can assist in identifying dietary patterns that both improve nutrition and reduce environmental impacts. Here we review 12 recent studies in which such optimization was used to achieve nutrition and environmental sustainability aims. These studies used data from China, India, and Tunisia, and from 7 high-income countries (France, Finland, Italy, the Netherlands, Sweden, the United Kingdom, and the United States). Most studies aimed to reduce greenhouse gas emissions (10 of 12) and half aimed also to reduce ≥1 other environmental impact, e.g., water use, fossil energy use, land use, marine eutrophication, atmospheric acidification, and nitrogen release. The main findings were that in all 12 studies, the diets optimized for sustainability and nutrition were more plant based with reductions in meat, particularly ruminant meats such as beef and lamb (albeit with 6 of 12 of studies involving increased fish in diets). The amount of dairy products also tended to decrease in most (7 of 12) of the studies with more optimized diets. Other foods that tended to be reduced included: sweet foods (biscuits, cakes, and desserts), savory snacks, white bread, and beverages (alcoholic and soda drinks). These findings were broadly compatible with the findings of 7 out of 8 recent review articles on the sustainability of diets. The literature suggests that healthy and sustainable diets may typically be cost neutral or cost saving, but this is still not clear overall. There remains scope for improvement in such areas as expanding research where there are no competing interests; improving sustainability metrics for food production and consumption; consideration of infectious disease risks from livestock agriculture and meat; and researching optimized diets in settings where major policy changes have occurred (e.g., Mexico's tax on unhealthy food).

Potential of active transport to improve health, reduce healthcare costs, and reduce greenhouse gas emissions: A modelling study.

BACKGROUND: Physical inactivity contributes substantively to disease burden, especially in highly car dependent countries such as New Zealand (NZ). We aimed to quantify the future health gain, health-sector cost-savings, and change in greenhouse gas emissions that could be achieved by switching short vehicle trips to walking and cycling in New Zealand. METHODS: We used unit-level survey data to estimate changes in physical activity, distance travelled by mode, and air pollution for: (a) switching car trips under 1km to walking and (b) switching car trips under 5km to a mix of walking and cycling. We modelled uptake levels of 25%, 50%, and 100%, and assumed changes in transport behaviour were permanent. We then used multi-state life table modelling to quantify health impacts as quality adjusted life years (QALYs) gained and changes in health system costs over the rest of the life course of the NZ population alive in 2011 (n = 4.4 million), with 3% discounting. FINDINGS: The modelled scenarios resulted in health gains between 1.61 (95% uncertainty interval (UI) 1.35 to 1.89) and 25.43 (UI 20.20 to 30.58) QALYs/1000 people, with total QALYs up to 112,020 (UI 88,969 to 134,725) over the remaining lifespan. Healthcare cost savings ranged between NZ$127million (UI $101m to 157m) and NZ$2.1billion (UI $1.6b to 2.6b). Greenhouse gas emissions were reduced by up to 194kgCO2e/year, though changes in emissions were not significant under the walking scenario. CONCLUSIONS: Substantial health gains and healthcare cost savings could be achieved by switching short car trips to walking and cycling. Implementing infrastructural improvements and interventions to encourage walking and cycling is likely to be a cost-effective way to improve population health, and may also reduce greenhouse gas emissions.

Potential Country-level Health and Cost Impacts of Legalizing Domestic Sale of Vaporized Nicotine Products.

BACKGROUND: The net impact on population health and health system costs of vaporized nicotine products is uncertain. We modeled, with uncertainty, the health and cost impacts of liberalizing the vaporized nicotine market for a high-income country, New Zealand (NZ). METHODS: We used a multistate life-table model of 16 tobacco-related diseases to simulate lifetime quality-adjusted life-years (QALYs) and health system costs at a 0% discount rate. We incorporated transitions from never, former, and current smoker states to, and from, regularly using vaporized nicotine and literature estimates for relative risk of disease incidence for vaping compared with smoking. RESULTS: Compared with continuation of baseline trends in smoking uptake and cessation rates and negligible vaporized nicotine use, we projected liberalizing the market for these products to gain 236,000 QALYs (95% uncertainty interval [UI] = 27,000 to 457,000) and save NZ$3.4 billion (2011 NZ$) (95% UI = NZ$370 million to NZ$7.1 billion) or US$2.5 billion (2017 NZ$). However, estimates of net health gains for 0- to 14-year olds and 65+ year olds had 95% UIs including the null. Uncertainty around QALYs gained was mainly driven by uncertainty around the impact of vaporized nicotine products on population-wide cessation rates and the relative health risk of vaping compared with smoking. CONCLUSIONS: This modeling suggested that a fairly permissive regulatory environment around vaporized nicotine products achieves net health gain and cost savings, albeit with wide uncertainty. Our results suggest that optimal strategies will also be influenced by targeted smoking cessation advice, regulations around chemical constituents of these products, and marketing and age limits to prevent youth uptake of vaping.

Restricting tobacco sales to only pharmacies combined with cessation advice: a modelling study of the future smoking prevalence, health and cost impacts.

OBJECTIVE: Restricting tobacco sales to pharmacies only, including the provision of cessation advice, has been suggested as a potential measure to hasten progress towards the tobacco endgame. We aimed to quantify the impacts of this hypothetical intervention package on future smoking prevalence, population health and health system costs for a country with an endgame goal: New Zealand (NZ). METHODS: We used two peer-reviewed simulation models: 1) a dynamic population forecasting model for smoking prevalence and 2) a closed cohort multi-state life-table model for future health gains and costs by sex, age and ethnicity. Greater costs due to increased travel distances to purchase tobacco were treated as an increase in the price of tobacco. Annual cessation rates were multiplied with the effect size for brief opportunistic cessation advice on sustained smoking abstinence. RESULTS: The intervention package was associated with a reduction in future smoking prevalence, such that by 2025 prevalence was 17.3%/6.8% for Maori (Indigenous)/non-Maori compared to 20.5%/8.1% projected under no intervention. The measure was furthermore estimated to accrue 41 700 discounted quality-adjusted life-years (QALYs) (95% uncertainty interval (UI): 33 500 to 51 600) over the remainder of the 2011 NZ population's lives. Of these QALYs gained, 74% were due to the provision of cessation advice over and above the limiting of sales to pharmacies. CONCLUSIONS: This work provides modelling-level evidence that the package of restricting tobacco sales to only pharmacies combined with cessation advice in these settings can accelerate progress towards the tobacco endgame, and achieve large population health benefits and cost-savings. :.

Impact of five tobacco endgame strategies on future smoking prevalence, population health and health system costs: two modelling studies to inform the tobacco endgame.

OBJECTIVE: There is growing international interest in advancing 'the tobacco endgame'. We use New Zealand (Smokefree goal for 2025) as a case study to model the impacts on smoking prevalence (SP), health gains (quality-adjusted life-years (QALYs)) and cost savings of (1) 10% annual tobacco tax increases, (2) a tobacco-free generation (TFG), (3) a substantial outlet reduction strategy, (4) a sinking lid on tobacco supply and (5) a combination of 1, 2 and 3. METHODS: Two models were used: (1) a dynamic population forecasting model for SP and (2) a closed cohort (population alive in 2011) multistate life table model (including 16 tobacco-related diseases) for health gains and costs. RESULTS: All selected tobacco endgame strategies were associated with reductions in SP by 2025, down from 34.7%/14.1% for Maori (indigenous population)/non-Maori in 2011 to 16.0%/6.8% for tax increases; 11.2%/5.6% for the TFG; 17.8%/7.3% for the outlet reduction; 0% for the sinking lid; and 9.3%/4.8% for the combined strategy. Major health gains accrued over the remainder of the 2011 population's lives ranging from 28 900 QALYs (95% Uncertainty Interval (UI)): 16 500 to 48 200; outlet reduction) to 282 000 QALYs (95%UI: 189 000 to 405 000; sinking lid) compared with business-as-usual (3% discounting). The timing of health gain and cost savings greatly differed for the various strategies (with accumulated health gain peaking in 2040 for the sinking lid and 2070 for the TFG). CONCLUSIONS: Implementing endgame strategies is needed to achieve tobacco endgame targets and reduce inequalities in smoking. Given such strategies are new, modelling studies provide provisional information on what approaches may be best.

A cross-sectional survey of cardiovascular health and lifestyle habits of hospital staff in the UK: Do we look after ourselves?

Background A high prevalence of stress-related disorders is well known among healthcare professionals. We set out to assess the prevalence of cardiovascular risk factors and compliance with national dietary and physical activity recommendations in NHS staff in the UK with comparison between clinical and non-clinical staff, and national surveys. Design A multi-centre cross-sectional study. Methods A web-based questionnaire was developed to include anonymised data on demographics, job role, cardiovascular risk factors and diseases, dietary habits, physical activity and barriers towards healthy lifestyle. This was distributed to staff in four NHS hospitals via emails. Results A total of 1158 staff completed the survey (response rate 13%) with equal distribution between the clinical and non-clinical groups. Most staff were aged 26-60 years and 79% were women. Half of the staff were either overweight or obese (51%) with no difference between the groups ( P = 0.176), but there was a lower prevalence of cardiovascular risk factors compared to the general population. The survey revealed a low compliance (17%) with the recommended intake of five-a-day portions of fruit and vegetables, and that of moderate or vigorous physical activity (56%), with no difference between the clinical and non-clinical staff ( P = 0.6). However, more clinical staff were exceeding the alcohol recommendations ( P = 0.02). Lack of fitness facilities and managerial support, coupled with long working hours, were the main reported barriers to a healthy lifestyle. Conclusions In this survey of UK NHS staff, half were found to be overweight or obese with a lower prevalence of cardiovascular risk factors compared to the general population. There was a low compliance with the five-a-day fruit and vegetables recommendation and physical activity guidelines, with no difference between the clinical and non-clinical staff.

Impact of increasing tobacco taxes on working-age adults: short-term health gain, health equity and cost savings.

OBJECTIVE: The health gains and cost savings from tobacco tax increase peak many decades into the future. Policy-makers may take a shorter-term perspective and be particularly interested in the health of working-age adults (given their role in economic productivity). Therefore, we estimated the impact of tobacco taxes in this population within a 10-year horizon. METHODS: As per previous modelling work, we used a multistate life table model with 16 tobacco-related diseases in parallel, parameterised with rich national data by sex, age and ethnicity. The intervention modelled was 10% annual increases in tobacco tax from 2011 to 2020 in the New Zealand population (n=4.4 million in 2011). The perspective was that of the health system, and the discount rate used was 3%. RESULTS: For this 10-year time horizon, the total health gain from the tobacco tax in discounted quality-adjusted life years (QALYs) in the 20-65 year age group (age at QALY accrual) was 180 QALYs or 1.6% of the lifetime QALYs gained in this age group (11 300 QALYs). Nevertheless, for this short time horizon: (1) cost savings in this group amounted to NZ$10.6 million (equivalent to US$7.1 million; 95% uncertainty interval: NZ$6.0 million to NZ$17.7 million); and (2) around two-thirds of the QALY gains for all ages occurred in the 20-65 year age group. Focusing on just the preretirement and postretirement ages, the QALY gains in each of the 60-64 and 65-69 year olds were 11.5% and 10.6%, respectively, of the 268 total QALYs gained for all age groups in 2011-2020. CONCLUSIONS: The majority of the health benefit over a 10-year horizon from increasing tobacco taxes is accrued in the working-age population (20-65 years). There remains a need for more work on the associated productivity benefits of such health gains.

A national quitline service and its promotion in the mass media: modelling the health gain, health equity and cost-utility.

BACKGROUND: Mass media campaigns and quitlines are both important distinct components of tobacco control programmes around the world. But when used as an integrated package, the effectiveness and cost-effectiveness are not well described. We therefore aimed to estimate the health gain, health equity impacts and cost-utility of the package of a national quitline service and its promotion in the mass media. METHODS: We adapted an established Markov and multistate life-table macro-simulation model. The population was all New Zealand adults in 2011. Effect sizes and intervention costs were based on past New Zealand quitline data. Health system costs were from a national data set linking individual health events to costs. RESULTS: The 1-year operation of the existing intervention package of mass media promotion and quitline service was found to be net cost saving to the health sector for all age groups, sexes and ethnic groups (saving $NZ84 million; 95%uncertainty interval 60-115 million in the base-case model). It also produced greater per capita health gains for Maori (indigenous) than non-Maori (2.2 vs 0.73 quality-adjusted life-years (QALYs) per 1000 population, respectively). The net cost saving of the intervention was maintained in all sensitivity and scenario analyses for example at a discount rate of 6% and when the intervention effect size was quartered (given the possibility of residual confounding in our estimates of smoking cessation). Running the intervention for 20 years would generate an estimated 54 000 QALYs and $NZ1.10 billion (US$0.74 billion) in cost savings. CONCLUSIONS: The package of a quitline service and its promotion in the mass media appears to be an effective means to generate health gain, address health inequalities and save health system costs. Nevertheless, the role of this intervention needs to be compared with other tobacco control and health sector interventions, some of which may be even more cost saving.

Glycemic index, glycemic load, and blood pressure: a systematic review and meta-analysis of randomized controlled trials.

Background: High blood pressure is a strong risk factor for cardiovascular disease.Objective: The aim of this study was to determine the associations of dietary glycemic index (GI) and glycemic load (GL) with systolic blood pressure (SBP) and diastolic blood pressure (DBP) in healthy individuals.Design: A systematic review and meta-analysis of randomized controlled trials (RCTs) was carried out. Databases were searched for eligible RCTs in 2 phases. MEDLINE, Embase, CAB Abstracts, BIOSIS, ISI Web of Science, and the Cochrane Library were searched from January 1990 to December 2009. An updated search was undertaken with the use of MEDLINE and Embase from January 2010 to September 2016. Trials were included if they reported author-defined high- and low-GI or -GL diets and blood pressure, were of ≥6 wk duration, and comprised healthy participants without chronic conditions. Data were extracted and analyzed with the use of Stata statistical software. Pooled estimates and 95% CIs were calculated with the use of weighted mean differences and random-effects models.Results: Data were extracted from 14 trials comprising 1097 participants. Thirteen trials provided information on differences in GI between control and intervention arms. A median reduction in GI of 10 units reduced the overall pooled estimates for SBP and DBP by 1.1 mm Hg (95% CI: -0.3, 2.5 mm Hg; P = 0.11) and 1.3 mm Hg (95% CI: 0.2 mm Hg, 2.3; P = 0.02), respectively. Nine trials reported information on differences in GL between arms. A median reduction in GL of 28 units reduced the overall pooled estimates for SBP and DBP by 2.0 mm Hg (95% CI: 0.2, 3.8 mm Hg; P = 0.03) and 1.4 mm Hg (95% CI: 0.1, 2.6 mm Hg; P = 0.03), respectively.Conclusions: This review of healthy individuals indicated that a lower glycemic diet may lead to important reductions in blood pressure. However, many of the trials included in the analysis reported important sources of bias. This trial was registered at PROSPERO as CRD42016049026.

Correction: Health, Health Inequality, and Cost Impacts of Annual Increases in Tobacco Tax: Multistate Life Table Modeling in New Zealand.

[This corrects the article DOI: 10.1371/journal.pmed.1001856.].

The benefits of constraining processed meat and red meat consumption in New Zealand: a public health perspective.

There is now strong scientific evidence of an increased risk of colorectal cancer with processed meat consumption, some evidence of red meats being associated with colorectal cancer and some evidence of an association between red and processed meat and cardiovascular disease and type 2 diabetes. This is important as these diseases collectively impose substantial health loss for New Zealanders and also large costs on publicly-funded health systems. There are also other indirect health issues involved with meat production including pollution of waterways and greenhouse gas (GHG) emissions from ruminant agriculture that contribute to climate change. Fortunately, there are a range of plausible options for New Zealand agencies to consider (such as GHG taxes applied to agriculture and health warning labels), if they decide to encourage reductions in the consumption of processed and red meat consumption in this country.

Tobacco retail outlet restrictions: health and cost impacts from multistate life-table modelling in a national population.

BACKGROUND: Since there is some evidence that the density and distribution of tobacco retail outlets may influence smoking behaviours, we aimed to estimate the impacts of 4 tobacco outlet reduction interventions in a country with a smoke-free goal: New Zealand (NZ). METHODS: A multistate life-table model of 16 tobacco-related diseases, using national data by sex, age and ethnicity, was used to estimate quality-adjusted life years (QALYs) gained and net costs over the remainder of the 2011 NZ population's lifetime. The outlet reduction interventions assumed that increased travel costs can be operationalised as equivalent to price increases in tobacco. RESULTS: All 4 modelled interventions led to reductions of >89% of current tobacco outlets after the 10-year phase-in process. The most effective intervention limited sales to half of liquor stores (and nowhere else) at 129 000 QALYs gained over the lifetime of the population (95% UI: 74 100 to 212 000, undiscounted). The per capita QALY gains were up to 5 times greater for Maori (indigenous population) compared to non-Maori. All interventions were cost-saving to the health system, with the largest saving for the liquor store only intervention: US$1.23 billion (95% UI: $0.70 to $2.00 billion, undiscounted). CONCLUSIONS: These tobacco outlet reductions reduced smoking prevalence, achieved health gains and saved health system costs. Effects would be larger if outlet reductions have additional spill-over effects (eg, smoking denormalisation). While these interventions were not as effective as tobacco tax increases (using the same model), these and other strategies could be combined to maximise health gain and to maximise cost-savings to the health system.

Study protocol: combining experimental methods, econometrics and simulation modelling to determine price elasticities for studying food taxes and subsidies (The Price ExaM Study).

BACKGROUND: There is a need for accurate and precise food price elasticities (PE, change in consumer demand in response to change in price) to better inform policy on health-related food taxes and subsidies. METHODS/DESIGN: The Price Experiment and Modelling (Price ExaM) study aims to: I) derive accurate and precise food PE values; II) quantify the impact of price changes on quantity and quality of discrete food group purchases and; III) model the potential health and disease impacts of a range of food taxes and subsidies. To achieve this, we will use a novel method that includes a randomised Virtual Supermarket experiment and econometric methods. Findings will be applied in simulation models to estimate population health impact (quality-adjusted life-years [QALYs]) using a multi-state life-table model. The study will consist of four sequential steps: 1. We generate 5000 price sets with random price variation for all 1412 Virtual Supermarket food and beverage products. Then we add systematic price variation for foods to simulate five taxes and subsidies: a fruit and vegetable subsidy and taxes on sugar, saturated fat, salt, and sugar-sweetened beverages. 2. Using an experimental design, 1000 adult New Zealand shoppers complete five household grocery shops in the Virtual Supermarket where they are randomly assigned to one of the 5000 price sets each time. 3. Output data (i.e., multiple observations of price configurations and purchased amounts) are used as inputs to econometric models (using Bayesian methods) to estimate accurate PE values. 4. A disease simulation model will be run with the new PE values as inputs to estimate QALYs gained and health costs saved for the five policy interventions. DISCUSSION: The Price ExaM study has the potential to enhance public health and economic disciplines by introducing internationally novel scientific methods to estimate accurate and precise food PE values. These values will be used to model the potential health and disease impacts of various food pricing policy options. Findings will inform policy on health-related food taxes and subsidies. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12616000122459 (registered 3 February 2016).

The health gains and cost savings of dietary salt reduction interventions, with equity and age distributional aspects.

BACKGROUND: A "diet high in sodium" is the second most important dietary risk factor for health loss identified in the Global Burden of Disease Study 2013. We therefore aimed to model health gains and costs (savings) of salt reduction interventions related to salt substitution and maximum levels in bread, including by ethnicity and age. We also ranked these four interventions compared to eight other modelled interventions. METHODS: A Markov macro-simulation model was used to estimate QALYs gained and net health system costs for four dietary sodium reduction interventions, discounted at 3 % per annum. The setting was New Zealand (NZ) (2.3 million adults, aged 35+ years) which has detailed individual-level administrative cost data. RESULTS: The health gain was greatest for an intervention where most (59 %) of the sodium in processed foods was replaced by potassium and magnesium salts. This intervention gained 294,000 QALYs over the remaining lifetime of the cohort (95 % UI: 238,000 to 359,000; 0.13 QALY per 35+ year old). Such salt substitution also produced the highest net cost-savings of NZ$ 1.5 billion (US$ 1.0 billion) (95 % UI: NZ$ 1.1 to 2.0 billion). All interventions generated relatively larger per capita QALYs for men vs women and for the indigenous Maori population vs non-Maori (e.g., 0.16 vs 0.12 QALYs per adult for the 59 % salt substitution intervention). Of relevance to workforce productivity, in the first 10 years post-intervention, 22 % of the QALY gain was among those aged <65 years (and 37 % for those aged <70). CONCLUSIONS: The benefits are consistent with the international literature, with large health gains and cost savings possible from some, but not all, sodium reduction interventions. Health gain appears likely to occur among working-age adults and all interventions contributed to reducing health inequalities.

Can a dietary quality score derived from a short-form FFQ assess dietary quality in UK adult population surveys?

OBJECTIVE: To devise a measure of diet quality from a short-form FFQ (SFFFQ) for population surveys. To validate the SFFFQ against an extensive FFQ and a 24 h diet recall. DESIGN: Population-based cross-sectional survey. SETTING: East Leeds and Bolton in Northern England. SUBJECTS: Adults (n 1999) were randomly selected from lists of those registered with a general practitioner in the study areas, contacted by mail and asked to complete the SFFFQ. Responders were sent a longer FFQ to complete and asked if they would take part in a telephone-based 24 h diet recall. RESULTS: Results from 826 people completing the SFFFQ, 705 completing the FFQ and forty-seven completing the diet recall were included in the analyses. The dietary quality score (DQS), based on fruit, vegetable, oily fish, non-milk extrinsic sugar and fat intakes, showed significant agreement between the SFFFQ and the FFQ (κ=0·38, P<0·001). The DQS for the SFFFQ and the diet recall did not show significant agreement (κ=0·04, P=0·312). A number of single items on the SFFFQ predicted a 'healthy' DQS when calculated from the FFQ. The odds of having a healthy diet were increased by 27 % (95 % CI 9, 49 %, P<0·001) for an increase in fruit of 1 portion/d and decreased by 67 % (95 % CI 47, 79 %, P<0·001) for an increase in crisps of 1 portion/d. CONCLUSIONS: The SFFFQ has been shown to be an effective method of assessing diet quality. It provides an important method for determining variations in diet quality within and across different populations.