Imperial College London

Dr Kiara C-M Chang

Faculty of MedicineSchool of Public Health

NIHR Research Fellow
 
 
 
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chu-mei.chang

 
 
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Reynolds BuildingCharing Cross Campus

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Summary

 

Publications

Publication Type
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29 results found

Morales-Berstein F, Biessy C, Viallon V, Goncalves-Soares A, Casagrande C, Hemon B, Kliemann N, Cairat M, Blanco Lopez J, Al Nahas A, Chang C-M, Vamos E, Rauber F, Bertazzi Levy R, Barbosa Cunha D, Jakszyn P, ferrari P, Vineis P, Masala G, Catalano A, Sonestedt E, Borne Y, Katzke V, Bajracharya R, on behalf of the EPIC Networket al., 2023, Ultra-processed foods, adiposity and risk of head and neck cancer and oesophageal adenocarcinoma in the European Prospective Investigation into Cancer and Nutrition study: a mediation analysis, European Journal of Nutrition, ISSN: 0044-264X

Purpose:To investigate the role of adiposity in the associations between ultra-processed food (UPF) consumption and head and neck cancer (HNC) and oesophageal adenocarcinoma (OAC) in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort.Methods:Our study included 450,111 EPIC participants. We used Cox regressions to investigate the associations between the consumption of UPFs and HNC and OAC risk. A mediation analysis was performed to assess the role of body mass index (BMI) and waist-to-hip ratio (WHR) in these associations. In sensitivity analyses, we investigated accidental death as a negative control outcome.Results:During a mean follow-up of 14.13 ± 3.98 years, 910 and 215 participants developed HNC and OAC, respectively. A 10% g/d higher consumption of UPFs was associated with an increased risk of HNC (hazard ratio [HR] = 1.23, 95% confidence interval [CI] 1.14–1.34) and OAC (HR = 1.24, 95% CI 1.05–1.47). WHR mediated 5% (95% CI 3–10%) of the association between the consumption of UPFs and HNC risk, while BMI and WHR, respectively, mediated 13% (95% CI 6–53%) and 15% (95% CI 8–72%) of the association between the consumption of UPFs and OAC risk. UPF consumption was positively associated with accidental death in the negative control analysis.Conclusions:We reaffirmed that higher UPF consumption is associated with greater risk of HNC and OAC in EPIC. The proportion mediated via adiposity was small. Further research is required to investigate other mechanisms that may be at play (if there is indeed any causal effect of UPF consumption on these cancers).

Journal article

Weth N, Qi D, Chang K, Kyriakos C, Filippidis Fet al., 2023, Price differences between capsule, menthol non-capsule and unflavoured cigarettes in 65 countries in 2018, Preventive Medicine Reports, Vol: 34, Pages: 1-5, ISSN: 2211-3355

The global consumption of flavoured cigarettes, particularly capsule and menthol non-capsule cigarettes, has been rising rapidly. Their attractiveness has been fuelled by perceptions of improved palatability, along with industry marketing tactics such as lower price points in some regions. This study aimed to compare prices of unflavoured, capsule, and menthol non-capsule cigarettes across 65 countries by analysing 2018 cigarette price data from Euromonitor Passport. Median prices of capsule and menthol non-capsule cigarettes were each compared to unflavoured cigarettes at the country-level. Countries were included in the analysis if they contained price data for capsule or menthol non-capsule and unflavoured cigarettes (n = 65). The median price of capsule cigarettes was the same as unflavoured cigarettes in 12 out of 50 countries and not statistically different in another 31 countries (p > 0.05). Capsule cigarettes were more expensive than unflavoured cigarettes in five countries and cheaper in two (p < 0.05). The median price of menthol non-capsule cigarettes was the same as unflavoured cigarettes in 6 out of 51 countries and not statistically different in another 39 countries (p > 0.05). Menthol non-capsule cigarettes were more expensive than unflavoured cigarettes in five countries and cheaper in one country (p < 0.05). There was no pattern found in the pricing of capsule or menthol non-capsule cigarettes, suggesting variability in the tobacco industry’s pricing strategies across countries. Tailoring tobacco control policies to match national market conditions, particularly in countries with significant market shares of capsule and menthol non-capsule cigarettes could help address the public health threat posed by the tobacco epidemic.

Journal article

Lai HTM, Chang K, Sharabiani MTA, Valabhji J, Gregg EW, Middleton L, Majeed A, Pearson-Stuttard J, Millett C, Bottle A, Vamos EPet al., 2023, Twenty-year trajectories of cardio-metabolic factors among people with type 2 diabetes by dementia status in England: a retrospective cohort study, European Journal of Epidemiology, Vol: 38, Pages: 733-744, ISSN: 0393-2990

To assess 20-year retrospective trajectories of cardio-metabolic factors preceding dementia diagnosis among people with type 2 diabetes (T2D). We identified 227,145 people with T2D aged > 42 years between 1999 and 2018. Annual mean levels of eight routinely measured cardio-metabolic factors were extracted from the Clinical Practice Research Datalink. Multivariable multilevel piecewise and non-piecewise growth curve models assessed retrospective trajectories of cardio-metabolic factors by dementia status from up to 19 years preceding dementia diagnosis (dementia) or last contact with healthcare (no dementia). 23,546 patients developed dementia; mean (SD) follow-up was 10.0 (5.8) years. In the dementia group, mean systolic blood pressure increased 16-19 years before dementia diagnosis compared with patients without dementia, but declined more steeply from 16 years before diagnosis, while diastolic blood pressure generally declined at similar rates. Mean body mass index followed a steeper non-linear decline from 11 years before diagnosis in the dementia group. Mean blood lipid levels (total cholesterol, LDL, HDL) and glycaemic measures (fasting plasma glucose and HbA1c) were generally higher in the dementia group compared with those without dementia and followed similar patterns of change. However, absolute group differences were small. Differences in levels of cardio-metabolic factors were observed up to two decades prior to dementia diagnosis. Our findings suggest that a long follow-up is crucial to minimise reverse causation arising from changes in cardio-metabolic factors during preclinical dementia. Future investigations which address associations between cardiometabolic factors and dementia should account for potential non-linear relationships and consider the timeframe when measurements are taken.

Journal article

Laverty AA, Li CR, Chang KC-M, Millett C, Filippidis FTet al., 2023, Cigarette taxation and price differentials in 195 countries during 2014-2018, Tobacco Control, Vol: 32, Pages: 359-365, ISSN: 0964-4563

INTRODUCTION: Raising tobacco prices via increased taxation may be undermined by tobacco industry tactics to keep budget cigarettes on the market. Price differentials between budget and premium cigarettes allow smokers to trade down in the face of average price rises thus attenuating health benefits. This study examines global trends of price differentials and associations with taxation. METHODS: Ecological analysis of country-level panel data of 195 countries' price differentials was performed and compared against total, specific excise, ad valorem and other taxation. Price differentials were expressed as the difference between budget cigarette and premium pack prices (as % of premium pack prices). Two-level linear regression models with repeated measurements (2014, 2016 and 2018) nested within each country assessed the association between country-level taxation structures and price differentials, adjusted for year, geographical region and income group. RESULTS: Worldwide, median price differential between budget and premium 20-cigarette packs was 49.4% (IQR 25.9%-70.0%) in 2014 and 44.4% (IQR 22.5%-69.4%) in 2018 with significant regional variation. The largest price differentials in 2018 were in Africa, with the lowest in Europe. Total taxation was negatively associated with price differentials (-1.5%, 95% CI -2.5% to -0.4% per +10% total taxation) as was specific excise taxation (-2.5%, 95% CI -3.7% to -1.2% per +10% specific excise tax). We found no statistically significant association between ad valorem taxation and price differentials. CONCLUSION: Total levels of taxation and specific excise taxes were associated with smaller price differentials. Implementing high specific excise taxes may reduce price differentials and improve health outcomes.

Journal article

Chang C-M, Gunter M, Rauber F, Levy R, Huybrechts I, Kliemann N, Millett C, Vamos Eet al., 2023, Ultra-processed food consumption, cancer risk and cancer mortality: a large-scale prospective analysis within the UK Biobank, EClinicalMedicine, Vol: 56, Pages: 1-12, ISSN: 2589-5370

BackgroundGlobal dietary patterns are increasingly dominated by relatively cheap, highly palatable, and ready-to-eat ultra-processed foods (UPFs). However, prospective evidence is limited on cancer development and mortality in relation to UPF consumption. This study examines associations between UPF consumption and risk of cancer and associated mortality for 34 site-specific cancers in a large cohort of British adults.MethodsThis study included a prospective cohort of UK Biobank participants (aged 40–69 years) who completed 24-h dietary recalls between 2009 and 2012 (N = 197426, 54.6% women) and were followed up until Jan 31, 2021. Food items consumed were categorised according to their degree of food processing using the NOVA food classification system. Individuals’ UPF consumption was expressed as a percentage of total food intake (g/day). Prospective associations were assessed using multivariable Cox proportional hazards models adjusted for baseline socio-demographic characteristics, smoking status, physical activity, body mass index, alcohol and total energy intake.FindingsThe mean UPF consumption was 22.9% (SD 13.3%) in the total diet. During a median follow-up time of 9.8 years, 15,921 individuals developed cancer and 4009 cancer-related deaths occurred. Every 10 percentage points increment in UPF consumption was associated with an increased incidence of overall (hazard ratio, 1.02; 95% CI, 1.01–1.04) and specifically ovarian (1.19; 1.08–1.30) cancer. Furthermore, every 10 percentage points increment in UPF consumption was associated with an increased risk of overall (1.06; 1.03–1.09), ovarian (1.30; 1.13–1.50), and breast (1.16; 1.02–1.32) cancer-related mortality.InterpretationOur UK-based cohort study suggests that higher UPF consumption may be linked to an increased burden and mortality for overall and certain site-specific cancers especially ovarian cancer in women.FundingThe Cancer Research UK and World Cancer Re

Journal article

Chang K, Gunter MJ, Rauber F, Levy RB, Huybrechts I, Kliemann N, Millett C, Vamos EPet al., 2023, Ultra-processed food consumption, cancer risk and cancer mortality: a large-scale prospective analysis within the UK Biobank, ECLINICALMEDICINE, Vol: 56, Pages: 1-12

Journal article

Handakas E, Chang K, Khandpur N, Vamos EP, Millett C, Sassi F, Vineis P, Robinson Oet al., 2022, Metabolic profiles of ultra-processed food consumption and their role in obesity risk in British children, Clinical Nutrition, Vol: 41, Pages: 2537-2548, ISSN: 0261-5614

Background & aimsHigher consumption of ultra-processed foods (UPF) has been associated with childhood obesity, but underlying mechanisms remain unclear. We investigated plasma nuclear magnetic resonance metabolic profiles of higher UPF consumption and their role in obesity risk in the British ALSPAC cohort.MethodsWe performed cross-sectional and prospective metabolome wide association analyses of UPF, calculated from food diaries using the NOVA classification. In cross-sectional analysis, we tested the association between UPF consumption and metabolic profile at 7 years (N = 4528), and in the prospective analysis we tested the association between UPF consumption at 13 years and metabolic profile at 17 years (N = 3086). Effects of UPF-associated metabolites at 7 years on subsequent fat mass accumulation were assessed using growth curve models.ResultsAt 7 years, UPF was associated with 115 metabolic traits including lower levels of branched-chain and aromatic amino acids and higher levels of citrate, glutamine, and monounsaturated fatty acids, which were also associated with greater fat mass accumulation. Reported intake of nutrients mediated associations with most metabolites, except for citrate.ConclusionsUPF consumption among British children is associated with perturbation of multiple metabolic traits, many of which contribute to child obesity risk.

Journal article

Parnham JC, Chang K, Rauber F, Levy RB, von Hinke S, Laverty AA, Millett C, Vamos EPet al., 2022, The ultra-processed food content of school meals and packed lunches in the UK, 2008-17: a pooled cross-sectional study.

BACKGROUND: British children have the highest ultra-processed food (UPF) intake in Europe, concerning as UPF is linked to adverse health outcomes. Schools are a potential setting for intervention, yet the rate of UPFs consumed at schools is currently unknown. This study aimed to describe the UPF content of school food in the UK and to explore differences in UPF content by meal type (school meals and packed lunches [food from home]) and children's household income. METHODS: We performed a pooled cross-sectional analysis of 1895 primary school children (aged 4-11 years) and 1408 secondary school children (aged 11-18 years) using data from the UK's National Diet and Nutrition Survey (from Feb, 2008, to June, 2017). Student's meal type was recorded using food diaries. UPF intake was defined using the NOVA food classification system. Income was measured through interview. We used quantile regression models to assess the association between meal type and lunchtime UPF intake (by both the percentage of calories and weight). We stratified models by school phase (primary or secondary) and interacted meal type with income. FINDINGS: The majority of schoolchildren's lunch was defined as UPFs, with secondary school children having higher median intakes of UPFs than primary school children (78% kcal [IQR 58-95] vs 73% kcal [55-86). School meals were associated with a lower median UPF intake than packed lunches for primary school children (61% kcal [IQR 44-75] vs 81% kcal [71-91]) and for secondary school children (70% kcal [IQR 48-89] vs 84% kcal [65-99]). Results were similar when UPFs were analysed as a percentage of the total weight of lunch. Overall, income was inversely associated with UPF lunch content. However, in primary school children, there was no significant association between percentage of UPF content of school meals by weight. INTERPRETATION: In the first nationally representative study, we showed that UK school children have a high intake of UPFs at lunch. UPF in

Conference paper

Bijlani C, Vrinten C, Chang K, Hrobonova E, Lewis E, Seferidi P, Laverty A, Junghans C, Vamos EPet al., 2022, Changes in diet and physical activity after a pilot intervention to tackle childhood obesity in a deprived inner-London community: an observational cohort study., Lancet, Vol: 400 Suppl 1

BACKGROUND: Local authorities in England are uniquely positioned to modify obesogenic local environments contributing to childhood obesity. Evaluating the effects of local authority-led, community-wide approaches is challenging. This study examines changes in diet and physical activity in children aged 6-11 years after a 4-year, complex, community-based, pilot intervention in Golborne, one of the most deprived areas in London. METHODS: The Go-Golborne intervention aimed to shape the local environment by building on local assets, connecting stakeholders in local government and the community, and synchronising existing activities. Activities focused on six themes to make changes to local environments and reduce the consumption of sugary snacks and beverages, increase fruit and vegetable intake, promote healthy snacks, increase active play and travel, and reduce screen time. We analysed changes in self-reported diet and physical activity, collected annually in 2016-19, from children from six local schools. Results were compared with the data collected at baseline. We used multilevel, linear (for dietary outcomes), and logistic (for physical activity) random-slope regression models to examine changes in diet and physical activity by time on study, adjusting for baseline age, sex, ethnicity, deprivation quintile, school, and baseline weight status. Dietary outcomes were calculated by summing the total occasions a participant indicated they ate or drank a certain food or drink (reported as portions per day, expressed as a β coefficient). The physical activity outcomes were developed by creating six binary variables to distinguish those who were most active from those who were least active. FINDINGS: 1650 children (mean age 7·9 years [SD:1·6]; 808 [49%] girls and 842 [51%] boys) were included. After 3 years of follow-up, we noted reductions in sugary beverage consumption (adjusted β -0·43 portions [95% CI -0·55 to -0·32]; p<0

Journal article

Chang K, Millett C, Rauber F, Levy RB, Huybrechts I, Kliemann N, Gunter MJ, Vamos EPet al., 2022, Ultra-processed food consumption, cancer risk, and cancer mortality: a prospective cohort study of the UK Biobank.

BACKGROUND: Dietary patterns worldwide are increasingly displaced by many cheap, highly palatable, and ready-to-eat ultra-processed foods (UPFs). Higher UPF consumption has been linked to increased risk for obesity and cardiometabolic diseases, but prospective evidence is limited on cancer outcomes. This study aimed to examine the association between UPF consumption and risk for overall and site-specific cancer incidence and cancer mortality using the UK Biobank cohort. METHODS: 197 426 participants of the UK Biobank from England, Scotland, and Wales with 24-h dietary recall completed between 2009 and 2012 were included. Incident cancer cases were identified through data linkage to national cancer and mortality registries. Food items consumed were categorised according to their degree of food processing using the NOVA classification system. Individual UPF consumption were derived as a percentage of daily food intake. Prospective association was assessed using multivariable Cox proportional hazards models adjusted for baseline sociodemographic and lifestyle characteristics. For female-specific cancers, menopausal status, use of oral contraceptives, hormone replacement therapy, and parity were additionally adjusted. FINDINGS: Mean age was 58·0 years (SD 8·0); 54·6% of participants were women. During a median follow-up time of 9·8 years (IQR 9·4-10·6), 15 921 (8·1%) of 197 426 individuals developed cancer and 4009 (2·0%) cancer deaths were encountered. Consumption of UPFs was associated with a higher incidence of overall cancer (hazard ratio per 10% increment in UPF consumption was 1·02 [95% CI 1·01-1·04]; p=0·005) and ovarian cancer in females (1·19 [1·08-1·30]; p<0·001). Positive associations were identified for mortality of overall, breast, and ovarian cancers. INTERPRETATION: This large UK cohort study presents evidence of positive associations between

Conference paper

Kyriakos C, Qi D, Chang CM, Laverty A, Filippidis Fet al., 2022, Global market trends of flavour capsule and menthol cigarettes: An ecological analysis using commercial data across 78 countries, 2010-2020, Tobacco Induced Diseases, Vol: 20, Pages: 1-14, ISSN: 1617-9625

Introduction: This study describes market trends of flavour capsule cigarettes (FCCs) and menthol (non-capsule) cigarettes across 78 countries from 2010 to 2020 and examines country-level factors associated with market shares of these products.Methods: Market share and retail volume data came from the Euromonitor Passport database and country-level data came from the World Health Organization (WHO), World Bank, and International Monetary Fund. Multivariable linear fixed effects panel regression analyses were conducted to evaluate the relationship between predictor variables and market share of menthol and FCC, respectively.Results: The overall market share (i.e., the percentage retail volume out of total retail volume of all cigarette types) increased from 0.23% in 2010 to 4.5% in 2020 for FCCs and decreased from 5.0% to 3.8% for menthol cigarettes. Market shares of FCCs grew most rapidly in the Americas region and among upper-middle-income countries. Market shares of menthol cigarettes remained stable across most regions and were highest in the Western Pacific and Africa regions. The overall market share of FCCs was positively associated with unemployment rate (β=0.28, 95%CI: 0.12 to 0.44, p=0.001), and inversely associated with % of the population aged 15-29 (β=-0.57, 95%CI: -0.98 to -0.15, p=0.008), % of urban population (β=-0.88, 95%CI: -1.28 to -0.48, p<0.001), GDP PPP per capita (β=-0.13, 95%CI: -0.24 to -0.03, p=0.015), and age-standardised prevalence of cigarette smoking (β=-0.93, -1.38 to -0.49, p<0.001). In contrast, the overall market share of menthol was positively associated with urbanicity (β=0.24, 95%CI: 0.08 to 0.40, p=0.003), and negatively associated with unemployment rate (β=-0.09, 95%CI: -0.17 to -0.02, p=0.014).Conclusions: Global sales of FCCs grew substantially in the last decade, surpassing menthol (non-capsule) cigarettes, which also continued to be high in many regions. There is a need for increased

Journal article

Parnham J, Chang C-M, Rauber F, Levy RB, Millett C, Laverty AA, von Hinke S, Vamos EPet al., 2022, The ultra-processed food content of school meals and packed lunches in the United Kingdom, Nutrients, Vol: 14, Pages: 1-14, ISSN: 2072-6643

British children have the highest levels of ultra-processed food (UPF) consumption in Europe. Schools are posited as a positive setting for impacting dietary intake but the level of UPFs consumed at schools is currently unknown. This study determined the UPF content of school food in the UK. We conducted a pooled cross-sectional analysis of primary (4-11 years, n=1,895) and secondary schoolchildren (11-18 years, n=1,408) from the UK’s National Diet and Nutrition Survey (2008-2017). Multivariable quantile regression models determined the association between meal-type (school meal or packed lunch) and lunchtime UPF intake (NOVA food classification system). We showed that on average UPF intake was high in both primary (72.6% total lunch Kcal) and secondary schoolchildren (77.8 % total lunch Kcal). Higher UPF intakes were observed in packed lunch consumers, secondary schoolchildren, and those in lower income households. This study highlights the need for a renewed focus on school food. Better guidance and policies which consider levels of industrial processing in food served in schools is needed to ensure the dual benefit of encouraging school meal uptake and equitably improving children’s diet.

Journal article

Haney E, Parnham JC, Chang K, Laverty AA, von Hinke S, Pearson-Stuttard J, White M, Millett C, Vamos EPet al., 2022, Dietary quality of school meals and packed lunches: a national study of primary and secondary schoolchildren in the UK, PUBLIC HEALTH NUTRITION, ISSN: 1368-9800

Journal article

Parnham JC, Chang K, Millett C, Laverty A, von Hinke S, Pearson-Stuttard J, de Vocht F, White M, Vamos EPet al., 2022, The impact of the Universal Infant Free School Meal policy on dietary quality in English and Scottish primary school children: evaluation of a natural experiment, Nutrients, Vol: 14, ISSN: 2072-6643

The Universal Infant Free School Meal (UIFSM) policy was introduced in September 2014 in England and January 2015 in Scotland and offered all infant schoolchildren (ages 4-7 years) a free school lunch, regardless of income. Yet, impacts of UIFSM on dietary intakes and or social inequalities are not known. A difference-in-differences study using the National Diet and Nutrition Survey assessed pooled pre-UIFSM (2010-2014) and post-UIFSM (2014-2017) dietary data. English or Scottish infant schoolchildren (4-7 years; N=458) were the intervention group with junior schoolchildren (8-11 years; N=401) as controls. We found that implementation of UIFSM led to an increase in infant schoolchildren having a school meal. Impacts on key food groups such as fruit and vegetables or sweetened beverages were not seen. However, there was evidence that the UIFSM policy lowered consumption of foods associated with packed lunches, such as crisps, and some nutrients, such as total fat and sodium. Policy impacts differed by income group, with larger effect sizes in low-income children. In conclusion, evaluation of UIFSM demonstrated some improvements on dietary quality but the findings suggest school meal quality needs to be improved to fully realise the benefits of UIFSM.

Journal article

Radó MK, Laverty AA, Hone T, Chang K, Jawad M, Millett C, Been JV, Filippidis FTet al., 2022, Cigarette taxation and neonatal and infant mortality: a longitudinal analysis of 159 countries, PLOS Global Public Health, Vol: 2, ISSN: 2767-3375

Previous studies on the associations between cigarette taxes and infant survival have all been in high-income countries and did not examine the relative benefits of different taxation levels and structures. We evaluated longitudinal associations of cigarette taxes with neonatal and infant mortality globally. We applied country-level panel regressions using 2008–2018 annual mortality and biennial WHO tobacco taxation data. Complete data was available for 159 countries. Outcomes were neonatal and infant mortality. We conducted analyses by type of taxes (i.e. specific cigarette taxes, ad valorem taxes, and other taxes, import duties and VAT) and the income group classification of countries. Covariates included scores for other WHO recommended tobacco control policies, socioeconomic, health-care, and air quality measures. Secondary analyses investigated the associations between cigarette tax and cigarette consumption. We found that a 10 percentage-point increase in total cigarette tax as a percentage of the retail price was associated with a 2.6% (95% Confidence Interval [CI]: 1.9% to 3.2%) decrease in neonatal mortality and a 1.9% (95% CI: 1.3% to 2.6%) decrease in infant mortality globally. Estimates were similar for both excise and ad valorem taxes. We estimated that 231,220 (95% CI: 152,658 to 307,655) infant deaths could have been averted in 2018 if all countries had total cigarette tax at least 75%. 99.2% of these averted deaths would have been in low- and middle-income countries (LMICs). The secondary analysis supported causal interpretation of results by finding that a 10 percentage-point increase in taxes was associated with a reduction of 94.6 (95% CI: 32.7 to 156.5) in annual cigarette consumption per capita. Although causal inference is precarious due to the quasi-experimental design, we used a robust analytical approach and focused on within-country changes. Limitations include an inability to include data on roll-your-own tobacco, other forms of toba

Journal article

Parnham J, Millett C, Chang K, Laverty A, von Hinke S, Pearson-Stuttard J, Vamos Eet al., 2021, Is the Healthy Start scheme associated with increased food expenditure in low-income families with young children in the United Kingdom?, BMC Public Health, Vol: 21, Pages: 1-11, ISSN: 1471-2458

Introduction: Healthy Start is a food assistance programme in the United Kingdom (UK) which aims to provide a nutritional safety-net and enable low-income families on welfare benefits to access a healthier diet through the provision of food vouchers. Healthy Start was launched in 2006 but remains under-evaluated. This study aims to determine whether participation in the Healthy Start scheme is associated with differences in food expenditure in a nationally representative sample of households in the UK. Methods: Cross-sectional analyses of the Living Costs and Food Survey dataset (2010-2017). All households with a child (0-3 years) or pregnant woman were included in the analysis (n=4,869). Multivariable quantile regression compared the expenditure and quantity of fruit and vegetables (FV), infant formula and total food purchases. Four exposure groups were defined based on eligibility, participation and income (Healthy Start Participating, Eligible Non-participating, Nearly Eligible low-income and Ineligible high-income households).Results: Of 876 eligible households, 54% participated in Healthy Start. No significant differences were found in FV or total food purchases between participating and eligible non-participating households, but infant formula purchases were lower in Healthy Start participating households. Ineligible higher-income households had higher purchases of FV. Conclusion: This study did not find evidence of an association between Healthy Start participation and FV expenditure. Moreover, inequalities in FV purchasing persist in the UK. Higher participation and increased voucher value may be needed to improve programme performance and counteract the harmful effects of poverty on diet.

Journal article

Kyriakos C, Ahmad A, Chang K, Filippidis Fet al., 2021, Price differentials of tobacco products: A cross-sectional analysis of 79 countries, Tobacco Induced Diseases, Vol: 19, Pages: 1-9, ISSN: 1617-9625

Introduction:Increased taxation is one of the most effective tobacco control measures. Price differentials across tobacco product types may undermine the effectiveness of taxation policies by providing the option to switch to cheaper products rather than to quit. The aim of this study was to use commercial data to compare prices and price differentials of both cigarette and non-cigarette products across countries from all geographical regions.Methods:We analyzed 6920 price data points (i.e. product brands) from Euromonitor Passport 2016 for 12 types of tobacco products across 79 countries from the six WHO regions: Africa (n=5), Eastern Mediterranean (n=6), Europe (n=39), the Americas (n=15), South-East Asia (n=3), and Western Pacific (n=12). For each product and country, a price differential was computed as the percentage of minimum price to the median.Results:Median cigarette prices (US$) were highest in Western Pacific countries (4.00; range: 0.80–16.20) and European countries (3.80; range: 0.80–14.00), but lowest in African countries (2.00; range: 0.80–2.20). The medians of cigarette price differentials were largest in the Eastern Mediterranean (48.33%) and African regions (50.00%), but smallest in Europe (82.35%). Pipe tobacco and fine-cut tobacco were generally less expensive than cigarettes while cigars were the most expensive. However, there were wide variations in prices and price differentials across regions and tobacco products.Conclusions:We found substantial variations in prices and price differentials between countries and world regions across tobacco products, likely reflecting differences in taxation policies and structures. Findings identify types of tobacco products in specific geographical regions where price differentials are highest, thereby highlighting areas where taxation policies need improvement, for example through implementing specific excise taxes.

Journal article

Chang C-M, Mayne E, Laverty A, Agaku I, Filippidis Fet al., 2021, Cigarette prices in eight sub-Saharan African countries in 2018: a cross-sectional analysis, BMJ Open, Vol: 11, ISSN: 2044-6055

Objective: While the trend in smoking prevalence is decreasing worldwide, the number of male tobacco smokers is growing in Africa. This study compares the cigarette market in eight sub-Saharan African countries. This includes examining cigarette prices, pricing differentials, pack sizes and affordability at national and subnational levels.Design and setting: A cross-sectional data analysis using data from the Data on Alcohol and Tobacco in Africa (DATA) Project. The DATA Project was centrally coordinated by project supervisors following a standardised protocol. University students were recruited to conduct data collection and a total of 22 347 retail cigarette price data points collected between June and August 2018 were analysed (including Botswana, Ethiopia, Lesotho, Namibia, Nigeria, South Africa, Zambia and Zimbabwe). Prices were converted to US$ and standardised to the price of a 20-cigarette pack.Results: This research found large price differentials within provinces/states, with the gap between medium and minimum prices per 20-cigarette pack exceeding 50% of the medium price in 18 out of 24 provinces/states. Single cigarettes were widely available, especially in Lesotho and Ethiopia. Results of multivariable regression suggest prices (per 20-cigarette pack) were lower for cigarettes sold in packs than single sticks (−US$0.27, 95% CI: −US$0.39 to −US$0.23) and lower in less populated areas (−US$0.28 in rural compared with urban settings, 95% CI: −US$0.41 to −US$0.15). Availability of cheaper single cigarettes (lower per unit price than packed cigarettes) were identified for Lesotho and South Africa.Conclusions: These findings identify a varied picture in cigarette pricing in studied countries and suggest measures to tackle pricing differentials and availability of single sticks are warranted. These measures should counteract the potential health consequences of the increasing penetration of tobacco indus

Journal article

Chang K, Khandpur N, Neri D, Touvier M, Huybrechts I, Millett C, Vamos Eet al., 2021, Association between childhood consumption of ultraprocessed food and adiposity trajectories in the Avon Longitudinal Study of Parents and Children birth cohort, JAMA Pediatrics, Vol: 175, ISSN: 2168-6211

Importance Reports of associations between higher consumption of ultraprocessed foods (UPF) and elevated risks of obesity, noncommunicable diseases, and mortality in adults are increasing. However, associations of UPF consumption with long-term adiposity trajectories have never been investigated in children.Objective To assess longitudinal associations between UPF consumption and adiposity trajectories from childhood to early adulthood.Design, Setting, and Participants This prospective birth cohort study included children who participated in the Avon Longitudinal Study of Parents and Children (ALSPAC) in Avon County, southwest England. Children were followed up from 7 to 24 years of age during the study period from September 1, 1998, to October 31, 2017. Data were analyzed from March 1, 2020, to January 31, 2021.Exposures Baseline dietary intake data were collected using 3-day food diaries. Consumption of UPF (applying the NOVA food classification system) was computed as a percentage of weight contribution in the total daily food intake for each participant and categorized into quintiles.Main Outcomes and Measures Repeated recordings of objectively assessed anthropometrics (body mass index [BMI; calculated as weight in kilograms divided by height in meters squared], weight, and waist circumference) and dual-energy x-ray absorptiometry measurements (fat and lean mass indexes [calculated as fat and lean mass, respectively, divided by height in meters squared] and body fat percentage). Associations were evaluated using linear growth curve models and were adjusted for study covariates.Results A total of 9025 children (4481 [49.7%] female and 4544 [50.3%] male) were followed up for a median of 10.2 (interquartile range, 5.2-16.4) years. The mean (SD) UPF consumption at baseline was 23.2% (5.0%) in quintile 1, 34.7% (2.5%) in quintile 2, 43.4% (2.5%) in quintile 3, 52.7% (2.8%) in quintile 4, and 67.8% (8.1%) in quintile 5. Among those in the highest quintile of UPF

Journal article

Rauber F, Chang K, Vamos EP, da Costa Louzada ML, Monteiro CA, Millett C, Levy RBet al., 2021, Ultra-processed food consumption and risk of obesity: a prospective cohort study of UK Biobank, EUROPEAN JOURNAL OF NUTRITION, Vol: 60, Pages: 2169-2180, ISSN: 1436-6207

Journal article

Levy RB, Rauber F, Chang K, Louzada MLDC, Monteiro CA, Millett C, Vamos EPet al., 2021, Ultra-processed food consumption and type 2 diabetes incidence: A prospective cohort study., Clinical Nutrition, Vol: 40, Pages: 3608-3614, ISSN: 0261-5614

BACKGROUND: Ultra-processed foods account for more than 50% of daily calories consumed in several high-income countries, with sales of ultra-processed foods soaring globally, especially in middle-income countries. The objective of this study is to investigate the association between ultra-processed food (UPF) consumption and risk of type 2 diabetes (T2D) in a UK-based prospective cohort study. METHODS: Participants of the UK Biobank (2007-2019) aged 40-69 years without diabetes at recruitment who provided 24-h dietary recall and follow-up data were included. UPFs were defined using the NOVA food classification. Multivariable Cox proportional hazards regression models were used to evaluate the association between UPF consumption and the risk of T2D adjusting for socio-demographic, anthropometric and lifestyle characteristics. RESULTS: A total of 21,730 participants with a mean age of 55.8 years and mean UPF intake of 22.1% at baseline were included. During a mean follow-up of 5.4 years (116,956 person-years), 305 incident T2D cases were identified. In the fully adjusted model, compared with the group in the lowest quartile of UPF intake, the hazard ratio for T2D was 1.44, 1.04-2.02 in the group with the highest quartile of UPF consumption. A gradient of elevated risk of T2D associated with increasing quartiles of UPF intake was consistently observed (p value for trend < 0.028). A significantly increased risk of T2D was observed per 10 percentage points increment in UPF consumption ([adjusted HR]: 1.12, 95% confidence interval [CI]: 1.04-1.20). CONCLUSIONS: Our findings demonstrate that a diet high in UPFs is associated with a clinically important increased risk of T2D. Identifying and implementing effective public health actions to reduce UPF consumption in the UK and globally are urgently required.

Journal article

Filippidis F, Chang C-M, Blackmore I, Laverty Aet al., 2020, Prices and illicit trade of cigarettes in the European Union, a cross-sectional analysis, Nicotine and Tobacco Research, Vol: 22, Pages: 2271-2275, ISSN: 1462-2203

IntroductionWithin the context of the World Health Organization Framework Convention on Tobacco Control Protocol to Eliminate Illicit Trade in Tobacco Products and the impending revision of the EU directive on tobacco excise rules we assessed whether cigarettes price is linked to being offered illicit cigarettes.MethodsWe combined data being offered illicit cigarettes from the 2015 Special Eurobarometer Survey on Illicit Tobacco (N=27,672) with area-level data on Gross Domestic Product, unemployment, perceived corruption and sharing a border with a non-European Economic Area (non-EEA) state. We used the 2015 Weighted Average Price of cigarettes (WAP), which reflects the average price of a cigarette pack in each member state. We assessed associations between prices and illicit trade using 3-level ordered regression models.Results19.6% of respondents reported ever being offered illicit cigarettes, 6.4% repeatedly. In fully adjusted models WAP was not associated with being more likely to have been offered illicit market cigarettes more often (adjusted Odds Ratio=1.02, 95% Confidence Interval 0.91; 1.15). Sharing a border with a non-EEA member state was associated with increased likelihood of reporting being offered illicit cigarettes more often (1.73, 1.26;2.39).ConclusionThis study found no significant association between cigarette prices and reporting being offered illicit cigarettes; sharing a border with a non-EEA member state was linked to illicit trade. This study adds to evidence that increasing prices of cigarettes are not associated with illicit trade and that the focus should remain on securing supply chains, including through features such independent traceability systems.ImplicationsAfter adjusting for individual and regional factors, we did not identify an association between prices of cigarettes and likelihood of reporting being offered illicit cigarettes in the EU. Sharing a border with a non-EEA state however, was associated with increased likelihood of

Journal article

Palladino R, Vamos E, Chang K, Khunti K, Majeed A, Millett Cet al., 2020, Evaluation of the diabetes screening component of a national cardiovascular risk assessment programme in England: a retrospective cohort study, Scientific Reports, Vol: 10, ISSN: 2045-2322

Type 2 Diabetes (T2D) is increasing but the effectiveness of large-scale diabetes screening programmes is debated. We assessed associations between coverage of a national cardiovascular and diabetes risk assessment programme in England (NHS Health Check) and detection and management of incident cases of non-diabetic hyperglycaemia (NDH) and T2D. Retrospective analysis employing propensity score covariate adjustment method of prospectively collected data of 348,987 individuals aged 40–74 years and registered with 455 general practices in England (January 2009-May 2016). We examined differences in diagnosis of NDH and T2D, and changes in blood glucose levels and cardiovascular risk score between individuals registered with general practices with different levels (tertiles) of programme coverage. Over the study period 7,126 cases of NDH and 12,171 cases of T2D were detected. Compared with low coverage practices, incidence rate of detection in medium and high coverage practices were 15% and 19% higher for NDH and 10% and 9% higher for T2D, respectively. Individuals with NDH in high coverage practices had 0.2 mmol/L lower mean fasting plasma glucose and 0.9% lower cardiovascular risk score at follow-up. General practices actively participating in the programme had higher detection of NDH and T2D and improved management of blood glucose and cardiovascular risk factors.

Journal article

Nazar G, Chang KC-M, Srivastava S, Pearce N, Karan A, Millett Cet al., 2019, Impact of India’s National Tobacco Control Programme on bidi and cigarette consumption: a difference-in-differences analysis, Tobacco Control, Vol: 29, Pages: 103-110, ISSN: 0964-4563

Background Despite the importance of decreasing tobacco use to achieve mortality reduction targets of the Sustainable Development Goals in low-income and middle-income countries (LMICs), evaluations of tobacco control programmes in these settings are scarce. We assessed the impacts of India’s National Tobacco Control Programme (NTCP), as implemented in 42 districts during 2007–2009, on household-reported consumption of bidis and cigarettes.Methods Secondary analysis of cross-sectional data from nationally representative Household Consumer Expenditure Surveys (1999–2000; 2004–2005 and 2011–2012). Outcomes were: any bidi/cigarette consumption in the household and monthly consumption of bidi/cigarette sticks per person. A difference-in-differences two-part model was used to compare changes in bidi/cigarette consumption between NTCP intervention and control districts, adjusting for sociodemographic characteristics and time-based heterogeneity.Findings There was an overall decline in household-reported bidi and cigarette consumption between 1999–2000 and 2011–2012. However, compared with control districts, NTCP districts had no significantly different reductions in the proportions of households reporting bidi (adjusted OR (AOR): 1.03, 95% CI: 0.84 to 1.28) or cigarette (AOR: 1.01 to 95% CI: 0.82 to 1.26) consumption, or for the monthly per person consumption of bidi (adjusted coefficient: 0.07, 95% CI: −0.13 to 0.28) or cigarette (adjusted coefficient: −0.002, 95% CI: −0.26 to 0.26) sticks among bidi/cigarette consuming households.Interpretation Our findings indicate that early implementation of the NTCP may not have produced reductions in tobacco use reflecting generally poor performance against the Framework Convention for Tobacco Control objectives in India. This study highlights the importance of strengthening the implementation and enforcement of tobacco control policies in LMICs to ach

Journal article

Laverty AA, Vamos E, Millett C, Chang K, Filippidis F, Hopkinson Net al., 2019, Child awareness of and access to cigarettes – impacts of the point of sale display ban in England, Tobacco Control, Vol: 28, Pages: 526-531, ISSN: 0964-4563

Introduction England introduced a tobacco display ban for shops with >280 m2 floor area (‘partial ban’) in 2012, then a total ban in 2015. This study assessed whether these were linked to child awareness of and access to cigarettes.Methods Data come from the Smoking, Drinking and Drug Use survey, an annual survey of children aged 11–15 years for 2010–2014 and 2016. Multivariate logistic regression models assessed changes in having seen cigarettes on display, usual sources and ease of access to cigarettes in shopsResults During the partial display ban in 2012, 89.9% of children reported seeing cigarettes on display in the last year, which was reduced to 86.0% in 2016 after the total ban (adjusted OR 0.58, 95% CI 0.50 to 0.66). Reductions were similar in small shops (84.1% to 79.3%)%) and supermarkets (62.6% to 57.3%)%). Although the ban was associated with a reduction in the proportion of regular child smokers reporting that they bought cigarettes in shops (57.0% in 2010 to 39.8% in 2016), we did not find evidence of changes in perceived difficulty or being refused sale among those who still did.Discussion Tobacco point-of-sale display bans in England reduced the exposure of children to cigarettes in shops and coincided with a decrease in buying cigarettes in shops. However, children do not report increased difficulty in obtaining cigarettes from shops, highlighting the need for additional measures to tackle tobacco advertising, stronger enforcement of existing laws and measures such as licencing for tobacco retailers.

Journal article

Chang C, Vamos E, Palladino R, Majeed A, Lee T, Millett Cet al., 2018, Impact of the NHS Health Check on inequalities in cardiovascular disease risk: a difference-in-differences matching analysis, Publisher: BMJ Publishing Group, Pages: 11-18, ISSN: 0143-005X

Background We assessed impacts of a large, nationwide cardiovascular disease (CVD) risk assessment and management programme on sociodemographic group inequalities in (1) early identification of hypertension, type 2 diabetes (T2D) and chronic kidney disease (CKD); and (2) management of global CVD risk among high-risk individuals.Methods We obtained retrospective electronic medical records from the Clinical Practice Research Datalink for a randomly selected sample of 138 788 patients aged 40–74 years without known CVD or diabetes, who were registered with 462 practices between 2009 and 2013. We estimated programme impact using a difference-in-differences matching analysis that compared changes in outcome over time between attendees and non-attendees.Results National Health Service Health Check attendance was 21.4% (29 672/138 788). A significantly greater number of hypertension and T2D incident cases were identified in men than women (eg, an additional 4.02%, 95% CI 3.65% to 4.39%, and 2.08%, 1.81% to 2.35% cases of hypertension in men and women, respectively). A significantly greater number of T2D incident cases were identified among attendees living in the most deprived areas, but no differences were found for hypertension and CKD across socioeconomic groups. No major differences in CVD risk management were observed between sociodemographic subgroups (eg, programme impact on 10-year CVD risk score was −1.13%, −1.48% to −0.78% in male and −1.53%, −2.36% to −0.71% in female attendees).Conclusion During 2009–2013, the programme had low attendance and small overall impacts on early identification of disease and risk management. The age, sex and socioeconomic subgroups appeared to have derived similar level of benefits, leaving existing inequalities unchanged. These findings highlight the importance of population-wide interventions to address inequalities in CVD outcomes.

Conference paper

Woringer M, cecil E, watt H, chang K, hamid F, khunti K, dubois E, evason J, Majeed A, soljak Met al., 2017, Evaluation of community provision of a preventive cardiovascular programme - the National Health Service Health Check in reaching the under-served groups by primary care in England: cross sectional observational study, BMC Health Services Research, Vol: 17, ISSN: 1472-6963

Background:Cardiovascular disease (CVD) is the leading cause of premature mortality and a major contributor of health inequalities in England. Compared to more affluent and white counterparts, deprived people and ethnic minorities tend to die younger due to preventable CVD associated with lifestyle. In addition, deprived, ethnic minorities and younger people are less likely to be served by CVD prevention services. This study assessed the effectiveness of community-based outreach providers in delivering England’s National Health Services (NHS) Health Check programme, a CVD preventive programme to under-served groups.Methods:Between January 2008 and October 2013, community outreach providers delivered a preventive CVD programme to 50,573 individuals, in their local communities, in a single consultation without prescheduled appointments. Community outreach providers operated on evenings and weekends as well as during regular business hours in venues accessible to the general public. After exclusion criteria, we analysed and compared socio-demographic data of 43,177 Health Check attendees with the general population across 38 local authorities (LAs). We assessed variation between local authorities in terms of age, sex, deprivation and ethnicity structures using two sample t-tests and within local authority variation in terms of ethnicity and deprivation using Chi squared tests and two sample t-tests respectively.Results:Using Index of Multiple Deprivation, the mean deprivation score of the population reached by community outreach providers was 6.01 higher (p < 0.05) than the general population. Screened populations in 29 of 38 LAs were significantly more deprived (p < 0.05). No statistically significant difference among ethnic minority groups was observed between LAs. Nonetheless some LAs – namely Leicester, Thurrock, Sutton, South Tyneside, Portsmouth and Gateshead were very successful in recruiting ethnic minority groups. The mean proportion of men s

Journal article

CHANG C, LEE T, VAMOS E, SOLJAK M, JOHNSTON D, KHUNTI K, MAJEED A, MILLETT Cet al., 2016, Impact of NHS Health Check on cardiovascular disease risk: difference-in-differences matching analysis, Canadian Medical Association Journal, ISSN: 1488-2329

Journal article

Chang K, Soljak MA, Lee T, Woringer, Johnston, Khunti K, Majeed, Millettet al., 2015, Coverage of a national cardiovascular risk assessment and management programme (NHS Health Check): Retrospective database study, Preventive Medicine, Vol: 78, ISSN: 1096-0260

Journal article

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