Changes in UK price disparities between healthy and less healthy foods over 10 years: An updated analysis with insights in the context of inflationary increases in the cost-of-living from 2021

Food prices and affordability play an important role in influencing dietary choices, which in turn have implications for public health. With inflationary increases in the cost-of-living in the UK since 2021, understanding the dynamics of food prices becomes increasingly important. In this longitudinal study, we aimed to examine changes in food prices from 2013 to 2023 by food group and by food healthiness. We established a dataset spanning the years 2013-2023 by combining price data from the UK Consumer Price Index for food and beverage items with nutrient and food data from the UK nutrient databank and UK Department of Health & Social Care's National Diet and Nutrition Survey data. We calculated the price (£/100 kcal) for each food item by year as well as before and during the period of inflationary pressure, and classified items into food groups according to the UK Eatwell Guide and as either "more healthy" or "less healthy" using the UK nutrient profiling score model. In 2023, bread, rice, potatoes and pasta was cheapest (£0.12/100 kcal) and fruit and vegetables most expensive (£1.01/100 kcal). Less healthy food was cheaper than more healthy food (£0.33/100 kcal versus £0.81/100 kcal). Before the inflationary pressure period (from 2013 to late 2021), the price of foods decreased by 3%. After this period, the price of food increased by 22%: relative increases were highest in the food group milk and dairy food (31%) and less healthy category (26%). While healthier foods saw smaller relative price increases since 2021, they remain more expensive, potentially exacerbating dietary inequalities. Policy responses should ensure food affordability and mitigate price disparities via, for example, healthy food subsidies.

Explaining differential socioeconomic effects in population health interventions: development and application of a new tool to classify intervention agentic demand

BACKGROUND

The agentic demand of population health interventions (PHIs) might influence how interventions work. Highly agentic interventions (eg, information campaigns) rely on recipients noticing and responding to the intervention. Resources required for individuals to benefit from highly agentic interventions have a socioeconomical pattern, thus agentic demand might affect intervention effectiveness and equity. Systematic evidence exploring these associations is missing due to the absence of adequate tools to classify agentic demands. We aimed to develop such a tool and test its application.

METHODS

Our iterative development process involved: (1) systematic identification of diet and physical activity PHIs; (2) coding of intervention actors and actions; (3) data synthesis; (4) expert qualitative feedback; and (5) reliability assessment. We searched nine databases for articles published between Jan 1, 2010, and Aug 17, 2020. For all included articles, we coded the actors (people required to act within an intervention) and their actions (what they were required to do for the intervention to have its intended effects). We combined these codes for similar intervention types to develop overarching schematic flow chart diagrams used to identify concepts, and we organised these into a draft tool. After expert feedback, and we assessed inter-rater reliability of the final version. We applied the final tool in a proof-of-concept review, extracting studies from three existing equity-focused systematic reviews on tool category, overall intervention effect, and differential socioeconomic effects and visualised findings.

FINDINGS

We identified three concepts affecting agentic demands of intervention components: exposure, two levels (how recipients encounter the intervention); mechanism of action, five levels; and engagement, two levels (how recipients respond to the intervention). We then combined these concepts to form 20 categories that grouped together interventions with similar agentic demands. In the review, we applied the tool to 26 PHIs that included 163 components. Intervention components were concentrated in a small number of categories, and their categorisation was related to intervention equity but not to effectiveness.

INTERPRETATION

We present a novel tool to classify the agentic demand of PHIs and demonstrate its feasibility within a systematic review. Linking intervention types to their effect on inequalities enables these factors to be considered when designing or selecting interventions. Users of the tool can avoid implementing intervention types that are likely to widen inequalities or implement them alongside counter-strategies to minimise any adverse equity effects. Applying this tool within future research, policy, and practice to design, select, evaluate, and synthesise evidence from PHIs has the potential to advance our understanding of how interventions work and their effect on socioeconomic inequalities.

FUNDING

Public Health Policy Research Unit (PH-PRU), National Institute for Health and Care Research (NIHR) Policy Research Programme.

The conceptualisation and operationalisation of 'marketing' in public health research: a review of reviews focused on food marketing using principles from critical interpretive synthesis

BACKGROUND

Extensive public health research reports the nature, scope and effects of various marketing activities used by food and drinks companies to support the sale of their products. Such literature informs the regulation of food marketing that encourages unhealthy eating behaviours and poor diet-related health outcomes. However, it is not clear whether this literature consistently conceptualises and applies marketing, which could in turn influence the approach and efficacy of policies to regulate food marketing. We aimed to understand the conceptualisation and operationalisation of marketing in public health research of food marketing, eventually focusing on the conceptualisation of integrated marketing.

METHODS

We conducted a review of reviews that drew on scoping review methods and applied principles of critical interpretive synthesis. Five databases of peer-reviewed literature and websites of relevant organisations were searched in June - August 2020. Articles were screened against inclusion criteria to identify reviews examining food marketing in a health context. Informative text segments from included articles were coded using NVivo. Codes were grouped into synthetic constructs and a synthesising argument.

RESULTS

After screening against inclusion criteria, 60 publications were eligible for inclusion. Informative text segments from 24 publications were coded, after which no new codes were identified. Our synthesising argument was that the understanding of integrated marketing appeared inconsistent across publications, such as by differences in use of underlying conceptual frameworks and in the application of terms such as marketing strategy and tactics.

CONCLUSIONS

Using our synthesising argument, we suggest ways to improve the future study of food marketing in public health research, for example by using in-depth case studies to understand the integrated operation and effect of multi-component marketing strategies. Improving conceptual clarity in the study of food marketing in public health research has the potential to inform policy that is more reflective of the true nature of marketing, and thus more effective in combating food marketing effects and protecting public health.

PROTOCOL REGISTRATION

The review protocol was made publicly available on Open Science Framework prior to the start of the study (DOI: https://doi.org/10.17605/OSF.IO/VSJCW ).

1319Local impedance on a force sensing catheter predicts volumetric lesion temperature changes

Funding Acknowledgements

Study was funded by Boston Scientific

The effective delivery of RF energy is dependent on transmural tissue heating, with irreversible tissue necrosis occurring at a tissue temperature ≥ 50°C.  While multi-input lesion indexing algorithms can provide some value in predicting lesion durability, no clinically available metric measures tissue heating under the endocardial surface.  Temperature measured from the catheter at the tissue surface is a surrogate for intra-lesion heating, but variables such as intra-cardiac flow and catheter irrigation have the potential to make this measure unreliable.  A metric that assesses volumetric tissue heating would provide a superior method of predicting RF ablation in clinical practice.

This study evaluated a prototype catheter that measures local catheter impedance (LI) using ring and tip electrodes and contact force (CF) using inductive sensors with an electroanatomical mapping system.  In vitro, 51µm thermocouples were placed in explanted cardiac ventricular swine tissue to measure the temperature profile during RF delivery.  The correlation between the LI drop during RF and intra-lesion temperature was assessed. 

 A total of 44 lesions were created.  Intra-lesion temperature was measured using 3 51µm thermocouples placed 0mm, 2mm, and 4mm from the surface of the tissue. The probes were placed in-line, 0.5-1mm lateral to the catheter tip. Lesions were created at a constant force of 15 ± 3g at standard powers of 25W and 30W and high power of 50W for durations of 10s and 30s. LI drop correlated strongly with lesion depth (R = 0.81) while force time integral (FTI) did not correlate as strongly (R = 0.58).  As seen in Figure 1A (temperature traces inverted), a characteristic temperature increase was observed, with the greatest increase at the probes located in the lesion core (2mm).  Lower temperatures were observed in the probes exposed to irrigation flow/ bloodpool (0mm).  Notably, the LI drop (33Ω) demonstrated a similar slope to the 2mm temperature probe recordings (maximum 78°C).  There was a strong linear relationship between maximum intra-lesion temperature and LI drop (R = 0.74) (Figure 1B), while there was a very weak relationship between temperature and FTI (R = 0.36). There was a strong relationship between LI drop and maximum temperature in the first 5s across all powers (R = 0.81).  At 50W, both LI drop (22 ± 5Ω) and maximum temperature (66 ± 9°C) were greater than standard power.  For 30W, LI drop was 14 ± 6Ω and maximum temperature was 52 ± 7°C in the first 5 seconds. 

In this study, LI drop was highly correlated to intra-lesion temperature at standard and high power, demonstrating the sensitivity of the metric to volumetric heating under the tissue surface. A LI drop greater than 20Ω results in a tissue temperature >50°C, and a 30Ω LI drop likely results in a transmural temperature profile in 2mm tissue. The correlation of LI to the core lesion temperature provides a powerful, biophysical measure of tissue heating during RF ablation.

Abstract Figure 1

P2862Complementary use of contact force and local catheter impedance during RF ablation reduces ablation time in an in vivo swine model

Acknowledgement/Funding

This study was funded by Boston Scientific.