US County-Level Variation in Preterm Birth Rates, 2007-2019

Importance

Preterm birth is a leading cause of preventable neonatal morbidity and mortality. Preterm birth rates at the national level may mask important geographic variation in rates and trends at the county level.

Objective

To estimate age-standardized preterm birth rates by US county from 2007 to 2019.

Design, Setting, and Participants

This serial cross-sectional study used data from the National Center for Health Statistics composed of all live births in the US between 2007 and 2019. Data analyses were performed between March 22, 2022, and September 29, 2022.

Main Outcomes and Measures

Age-standardized preterm birth (<37 weeks' gestation) and secondarily early preterm birth (<34 weeks' gestation) rates by county and year calculated with a validated small area estimation model (hierarchical bayesian spatiotemporal model) and percent change in preterm birth rates using log-linear regression models.

Results

Between 2007 and 2019, there were 51 044 482 live births in 2383 counties. In 2007, the national age-standardized preterm birth rate was 12.6 (95% CI, 12.6-12.7) per 100 live births. Preterm birth rates varied significantly among counties, with an absolute difference between the 90th and 10th percentile counties of 6.4 (95% CI, 6.2-6.7). The gap between the highest and lowest counties for preterm births was 20.7 per 100 live births in 2007. Several counties in the Southeast consistently had the highest preterm birth rates compared with counties in California and New England, which had the lowest preterm birth rates. Although there was no statistically significant change in preterm birth rates between 2007 and 2019 at the national level (percent change, -5.0%; 95% CI, -10.7% to 0.9%), increases occurred in 15.4% (95% CI, 14.1%-16.9%) of counties. The absolute and relative geographic inequalities were similar across all maternal age groups. Higher quartile of the Social Vulnerability Index was associated with higher preterm birth rates (quartile 4 vs quartile 1 risk ratio, 1.34; 95% CI, 1.31-1.36), which persisted across the study period. Similar patterns were observed for early preterm birth rates.

Conclusions and Relevance

In this serial cross-sectional study of county-level preterm and early preterm birth rates, substantial geographic disparities were observed, which were associated with place-based social disadvantage. Stability in aggregated rates of preterm birth at the national level masked increases in nearly 1 in 6 counties between 2007 and 2019.

Projected health and economic impacts of sugar-sweetened beverage taxation in Germany: A cross-validation modelling study

BACKGROUND

Taxes on sugar-sweetened beverages (SSBs) have been implemented globally to reduce the burden of cardiometabolic diseases by disincentivizing consumption through increased prices (e.g., 1 peso/litre tax in Mexico) or incentivizing industry reformulation to reduce SSB sugar content (e.g., tiered structure of the United Kingdom [UK] Soft Drinks Industry Levy [SDIL]). In Germany, where no tax on SSBs is enacted, the health and economic impact of SSB taxation using the experience from internationally implemented tax designs has not been evaluated. The objective of this study was to estimate the health and economic impact of national SSBs taxation scenarios in Germany.

METHODS AND FINDINGS

In this modelling study, we evaluated a 20% ad valorem SSB tax with/without taxation of fruit juice (based on implemented SSB taxes and recommendations) and a tiered tax (based on the UK SDIL) in the German adult population aged 30 to 90 years from 2023 to 2043. We developed a microsimulation model (IMPACTNCD Germany) that captures the demographics, risk factor profile and epidemiology of type 2 diabetes, coronary heart disease (CHD) and stroke in the German population using the best available evidence and national data. For each scenario, we estimated changes in sugar consumption and associated weight change. Resulting cases of cardiometabolic disease prevented/postponed and related quality-adjusted life years (QALYs) and economic impacts from healthcare (medical costs) and societal (medical, patient time, and productivity costs) perspectives were estimated using national cost and health utility data. Additionally, we assessed structural uncertainty regarding direct, body mass index (BMI)-independent cardiometabolic effects of SSBs and cross-validated results with an independently developed cohort model (PRIMEtime). We found that SSB taxation could reduce sugar intake in the German adult population by 1 g/day (95%-uncertainty interval [0.05, 1.65]) for a 20% ad valorem tax on SSBs leading to reduced consumption through increased prices (pass-through of 82%) and 2.34 g/day (95%-UI [2.32, 2.36]) for a tiered tax on SSBs leading to 30% reduction in SSB sugar content via reformulation. Through reductions in obesity, type 2 diabetes, and cardiovascular disease (CVD), 106,000 (95%-UI [57,200, 153,200]) QALYs could be gained with a 20% ad valorem tax and 192,300 (95%-UI [130,100, 254,200]) QALYs with a tiered tax. Respectively, €9.6 billion (95%-UI [4.7, 15.3]) and €16.0 billion (95%-UI [8.1, 25.5]) costs could be saved from a societal perspective over 20 years. Impacts of the 20% ad valorem tax were larger when additionally taxing fruit juice (252,400 QALYs gained, 95%-UI [176,700, 325,800]; €11.8 billion costs saved, 95%-UI [€6.7, €17.9]), but impacts of all scenarios were reduced when excluding direct health effects of SSBs. Cross-validation with PRIMEtime showed similar results. Limitations include remaining uncertainties in the economic and epidemiological evidence and a lack of product-level data.

CONCLUSIONS

In this study, we found that SSB taxation in Germany could help to reduce the national burden of noncommunicable diseases and save a substantial amount of societal costs. A tiered tax designed to incentivize reformulation of SSBs towards less sugar might have a larger population-level health and economic impact than an ad valorem tax that incentivizes consumer behaviour change only through increased prices.

Guidance on the use of complex systems models for economic evaluations of public health interventions

To help health economic modelers respond to demands for greater use of complex systems models in public health. To propose identifiable features of such models and support researchers to plan public health modeling projects using these models. A working group of experts in complex systems modeling and economic evaluation was brought together to develop and jointly write guidance for the use of complex systems models for health economic analysis. The content of workshops was informed by a scoping review. A public health complex systems model for economic evaluation is defined as a quantitative, dynamic, non-linear model that incorporates feedback and interactions among model elements, in order to capture emergent outcomes and estimate health, economic and potentially other consequences to inform public policies. The guidance covers: when complex systems modeling is needed; principles for designing a complex systems model; and how to choose an appropriate modeling technique. This paper provides a definition to identify and characterize complex systems models for economic evaluations and proposes guidance on key aspects of the process for health economics analysis. This document will support the development of complex systems models, with impact on public health systems policy and decision making.

Association of Birth Year of Pregnant Individuals With Trends in Hypertensive Disorders of Pregnancy in the United States, 1995-2019

IMPORTANCE

Hypertensive disorders of pregnancy are leading causes of morbidity and mortality among pregnant individuals as well as newborns, with increasing incidence during the past decade. Understanding the individual associations of advancing age of pregnant individuals at delivery, more recent delivery year (period), and more recent birth year of pregnant individuals (cohort) with adverse trends in hypertensive disorders of pregnancy could help guide public health efforts to improve the health of pregnant individuals.

OBJECTIVE

To clarify the independent associations of delivery year and birth year of pregnant individuals, independent of age of pregnant individuals, with incident rates of hypertensive disorders of pregnancy.

DESIGN, SETTING, AND PARTICIPANTS

This serial cross-sectional study of 38 141 561 nulliparous individuals aged 15 to 44 years with a singleton, live birth used 1995-2019 natality data from the National Vital Statistics System.

EXPOSURES

Year of delivery (period) and birth year (cohort) of pregnant individuals.

MAIN OUTCOMES AND MEASURES

Rates of incident hypertensive disorders of pregnancy, defined as gestational hypertension, preeclampsia, or eclampsia, recorded on birth certificates. Generalized linear mixed models were used to calculate adjusted rate ratios (aRRs) comparing the incidence of hypertensive disorders of pregnancy in each delivery period (adjusted for age and cohort) and birth cohort (adjusted for age and period) with the baseline group as the reference for each. Analyses were additionally stratified by the self-reported racial and ethnic group of pregnant individuals.

RESULTS

Of 38 141 561 individuals, 20.2% were Hispanic, 0.8% were non-Hispanic American Indian or Alaska Native, 6.5% were non-Hispanic Asian or Pacific Islander, 13.9% were non-Hispanic Black, and 57.8% were non-Hispanic White. Among pregnant individuals who delivered in 2015 to 2019 compared with 1995 to 1999, the aRR for the incidence of hypertensive disorders of pregnancy was 1.59 (95% CI, 1.57-1.62), adjusted for age and cohort. Among pregnant individuals born in 1996 to 2004 compared with 1951 to 1959, the aRR for the incidence of hypertensive disorders of pregnancy was 2.61 (95% CI, 2.41-2.84), adjusted for age and period. The incidence was higher among self-identified non-Hispanic Black individuals in each birth cohort, with similar relative changes for period (aRR, 1.76 [95% CI, 1.70-1.81]) and cohort (aRR, 3.26 [95% CI, 2.72-3.91]) compared with non-Hispanic White individuals (period: aRR, 1.60 [95% CI, 1.57-1.63]; cohort: aRR, 2.53 [95% CI, 2.26-2.83]).

CONCLUSIONS AND RELEVANCE

This cross-sectional study suggests that more recent birth cohorts of pregnant individuals have experienced a doubling of rates of hypertensive disorders of pregnancy, even after adjustment for age and delivery period. Substantial racial and ethnic disparities persisted across generations.

What will the cardiovascular disease slowdown cost? Modelling the impact of CVD trends on dementia, disability, and economic costs in England and Wales from 2020–2029

Background

There is uncertainty around the health impact and economic costs of the recent slowing of the historical decline in cardiovascular disease (CVD) incidence and the future impact on dementia and disability.

Methods

Previously validated IMPACT Better Ageing Markov model for England and Wales, integrating English Longitudinal Study of Ageing (ELSA) data for 17,906 ELSA participants followed from 1998 to 2012, linked to NHS Hospital Episode Statistics. Counterfactual design comparing two scenarios: Scenario 1. CVD Plateau—age-specific CVD incidence remains at 2011 levels, thus continuing recent trends. Scenario 2. CVD Fall—age-specific CVD incidence goes on declining, following longer-term trends. The main outcome measures were age-related healthcare costs, social care costs, opportunity costs of informal care, and quality adjusted life years (valued at £60,000 per QALY).

Findings

The total 10 year cumulative incremental net monetary cost associated with a persistent plateauing of CVD would be approximately £54 billion (95% uncertainty interval £14.3-£96.2 billion), made up of some £13 billion (£8.8-£16.7 billion) healthcare costs, £1.5 billion (-£0.9-£4.0 billion) social care costs, £8 billion (£3.4-£12.8 billion) informal care and £32 billion (£0.3-£67.6 billion) value of lost QALYs.

Interpretation

After previous, dramatic falls, CVD incidence has recently plateaued. That slowdown could substantially increase health and social care costs over the next ten years. Healthcare costs are likely to increase more than social care costs in absolute terms, but social care costs will increase more in relative terms. Given the links between COVID-19 and cardiovascular health, effective cardiovascular prevention policies need to be revitalised urgently.

How can tobacco policy models quality be assessed: a systematic review

 

Policy simulation models (PSMs) have been used extensively, both to shape health policies before real-world implementation and to evaluate post-implementation impact. However, an accepted quality assessment framework for simulation models is lacking. This systematic review aimed to develop a novel quality assessment framework for tobacco control PSMs. We searched five databases to identify peer-reviewed tobacco control PSMs that projected tobacco-use and tobacco-related outcomes from smoking policy scenarios. We extracted information on modelling inputs, structure and outputs. Using our proposed quality assessment framework, we scored models on nine dimensions: representativeness of population, policy effectiveness evidence, simulated smoking histories, simulated smoking-related diseases, exposure-outcome lag time, transparency, sensitivity analysis, validation and equity. We then compared the model score with the number of cited papers using each model. The results were narratively presented. After screening 5046 candidate papers; 145 papers were included and categorised into 25 PSMs. After scoring the models using our proposed framework, we observed that seven models were given seven and more points. The higher-scored models were generally those with a higher number of publications. While all included models had been subject to sensitivity analysis, other best practices were often lacking. Nine models did not explicitly consider smoking-related diseases. Smoking histories were commonly collapsed into crude smoking status categories rather than reflecting smoking intensity or quitting history. Furthermore, only four models estimated policy equity impact. Our systematic review revealed a variety of modelling techniques used in tobacco control. Our novel quality assessment framework offers a potential quality measure for tobacco control policy simulation models. It may guide health decision modellers and inform health policymaking.

Key messages

All nine framework dimensions were observed in two tobacco control PSM, suggesting the framework relevance and feasibility. However, few models achieved high scores in all dimensions. This novel quality assessment framework aims to support the development and sharing of good modelling practice and thus promote better health policy decision-making.

Coronary heart disease and stroke mortality trends in Brazil 2000-2018

OBJECTIVE

To analyse the mortality rate trend due to coronary heart disease (CHD) and stroke in the adult population in Brazil.

METHODS

From 2000 to 2018, a time trend study with joinpoint regression was conducted among Brazilian men and women aged 35 years and over. Age-adjusted and age, sex specific CHD and stroke trend rate mortality were measured.

RESULTS

Crude mortality rates from CHD decreased in both sexes and in all age groups, except for males over 85 years old with an increase of 1.78%. The most accentuated declining occurred for age range 35 to 44 years for both men (52.1%) and women (53.2%) due to stroke and in men (33%) due to CHD, and among women (32%) aged 65 to 74 years due to CHD. Age-adjusted mortality rates for CHD and stroke decreased in both sexes, in the period from 2000 to 2018. The average annual rate for CHD went from 97.09 during 2000-2008 to 78.75 during 2016-2018, whereas the highest percentage of change was observed during 2008 to 2013 (APC -2.5%; 95% CI). The average annual rate for stroke decreased from 104.96 to 69.93, between 2000-2008 and 2016-2018, and the highest percentage of change occurred during the periods from 2008 to 2013 and 2016 to 2018 (APC 4.7%; 95% CI).

CONCLUSION

The downward trend CHD and stroke mortality rates is continuing. Policy intervention directed to strengthen care provision and improve population diets and lifestyles might explain the continued progress, but there is no room for complacency.

Explaining the increment in coronary heart disease mortality in Mexico between 2000 and 2012

BACKGROUND

Mexico is still in the growing phase of the epidemic of coronary heart disease (CHD), with mortality increasing by 48% since 1980. However, no studies have analyzed the drivers of these trends. We aimed to model CHD deaths between 2000 and 2012 in Mexico and to quantify the proportion of the mortality change attributable to advances in medical treatments and to changes in population-wide cardiovascular risk factors.

METHODS

We performed a retrospective analysis using the previously validated IMPACT model to explain observed changes in CHD mortality in Mexican adults. The model integrates nationwide data at two-time points (2000 and 2012) to quantify the effects on CHD mortality attributable to changes in risk factors and therapeutic trends.

RESULTS

From 2000 to 2012, CHD mortality rates increased by 33.8% in men and by 22.8% in women. The IMPACT model explained 71% of the CHD mortality increase. Most of the mortality increases could be attributed to increases in population risk factors, such as diabetes (43%), physical inactivity (28%) and total cholesterol (24%). Improvements in medical and surgical treatments together prevented or postponed 40.3% of deaths; 10% was attributable to improvements in secondary prevention treatments following MI, while 5.3% to community heart failure treatments.

CONCLUSIONS

CHD mortality in Mexico is increasing due to adverse trends in major risk factors and suboptimal use of CHD treatments. Population-level interventions to reduce CHD risk factors are urgently needed, along with increased access and equitable distribution of therapies.

Adverse Trends in Premature Cardiometabolic Mortality in the United States, 1999 to 2018

Background Life expectancy in the United States has recently declined, in part attributable to premature cardiometabolic mortality. We characterized national trends in premature cardiometabolic mortality, overall, and by race-sex groups. Methods and Results Using death certificates from the Centers for Disease Control and Prevention's Wide-Ranging Online Data for Epidemiologic Research, we quantified premature deaths (<65 years of age) from heart disease, cerebrovascular disease, and diabetes mellitus from 1999 to 2018. We calculated age-adjusted mortality rates (AAMRs) and years of potential life lost (YPLL) from each cardiometabolic cause occurring at <65 years of age. We used Joinpoint regression to identify an inflection point in overall cardiometabolic AAMR trends. Average annual percent change in AAMRs and YPLL was quantified before and after the identified inflection point. From 1999 to 2018, annual premature deaths from heart disease (117 880 to 128 832), cerebrovascular disease (18 765 to 20 565), and diabetes mellitus (16 553 to 24 758) as an underlying cause of death increased. By 2018, 19.7% of all heart disease deaths, 13.9% of all cerebrovascular disease deaths, and 29.1% of all diabetes mellitus deaths were premature. AAMRs and YPLL from heart disease and cerebrovascular disease declined until the inflection point identified in 2011, then remained unchanged through 2018. Conversely, AAMRs and YPLL from diabetes mellitus did not change through 2011, then increased through 2018. Black men and women had higher AAMRs and greater YPLL for each cardiometabolic cause compared with White men and women, respectively. Conclusions Over one-fifth of cardiometabolic deaths occurred at <65 years of age. Recent stagnation in cardiometabolic AAMRs and YPLL are compounded by persistent racial disparities.

Potential impacts of post-Brexit agricultural policy on fruit and vegetable intake and cardiovascular disease in England: a modelling study

Background

Current proposals for post-Brexit agricultural policy do not explicitly incorporate public health goals. The revised agricultural policy may be an opportunity to improve population health by supporting domestic production and consumption of fruits and vegetables (F&V). This study aims to quantify the potential impacts of a post-Brexit agricultural policy that increases land allocated to F&V on cardiovascular disease (CVD) mortality and inequalities in England, between 2021 to 2030.

Methods

We used the previously validated IMPACT Food Policy model and probabilistic sensitivity analysis to translate changes in land allocated to F&V into changes in F&V intake and associated CVD deaths, stratified by age, sex and Index of Multiple Deprivation. The model combined data on F&V agriculture, waste, purchases and intake, CVD mortality projections and appropriate relative risks. We modelled two scenarios, assuming that land allocated to F&V would gradually increase to 10% and 20% of land suitable for F&V production.

Results

We found that increasing land use for F&V production to 10% and 20% of suitable land would increase fruit intake by approximately 3.7% (95% uncertainty interval: 1.6% to 8.6%) and 17.4% (9.1% to 36.9%), and vegetable intake by approximately 7.8% (4.2% to 13.7%) and 37% (24.3% to 55.7%), respectively, in 2030. This would prevent or postpone approximately 3890 (1950 to 7080) and 18 010 (9840 to 28 870) CVD deaths between 2021 and 2030, under the first and second scenario, respectively. Both scenarios would reduce inequalities, with 16% of prevented or postponed deaths occurring among the least deprived compared with 22% among the most deprived.

Conclusion

Post-Brexit agricultural policy presents an important opportunity to improve dietary intake and associated cardiovascular mortality by supporting domestic production of F&V as part of a comprehensive strategy that intervenes across the supply chain.

Preventing type 2 diabetes mellitus in Qatar by reducing obesity, smoking, and physical inactivity: mathematical modeling analyses

BACKGROUND

The aim of this study was to estimate the impact of reducing the prevalence of obesity, smoking, and physical inactivity, and introducing physical activity as an explicit intervention, on the burden of type 2 diabetes mellitus (T2DM), using Qatar as an example.

METHODS

A population-level mathematical model was adapted and expanded. The model was stratified by sex, age group, risk factor status, T2DM status, and intervention status, and parameterized by nationally representative data. Modeled interventions were introduced in 2016, reached targeted level by 2031, and then maintained up to 2050. Diverse intervention scenarios were assessed and compared with a counter-factual no intervention baseline scenario.

RESULTS

T2DM prevalence increased from 16.7% in 2016 to 24.0% in 2050 in the baseline scenario. By 2050, through halting the rise or reducing obesity prevalence by 10-50%, T2DM prevalence was reduced by 7.8-33.7%, incidence by 8.4-38.9%, and related deaths by 2.1-13.2%. For smoking, through halting the rise or reducing smoking prevalence by 10-50%, T2DM prevalence was reduced by 0.5-2.8%, incidence by 0.5-3.2%, and related deaths by 0.1-0.7%. For physical inactivity, through halting the rise or reducing physical inactivity prevalence by 10-50%, T2DM prevalence was reduced by 0.5-6.9%, incidence by 0.5-7.9%, and related deaths by 0.2-2.8%. Introduction of physical activity with varying intensity at 25% coverage reduced T2DM prevalence by 3.3-9.2%, incidence by 4.2-11.5%, and related deaths by 1.9-5.2%.

CONCLUSIONS

Major reductions in T2DM incidence could be accomplished by reducing obesity, while modest reductions could be accomplished by reducing smoking and physical inactivity, or by introducing physical activity as an intervention.

Explaining income-related inequalities in cardiovascular risk factors in Tunisian adults during the last decade: comparison of sensitivity analysis of logistic regression and Wagstaff decomposition analysis

BACKGROUND

It is important to quantify inequality, explain the contribution of underlying social determinants and to provide evidence to guide health policy. The aim of the study is to explain the income-related inequalities in cardiovascular risk factors in the last decade among Tunisian adults aged between 35 and 70 years old.

METHODS

We performed the analysis by applying two approaches and compared the results provided by the two methods. The methods were global sensitivity analysis (GSA) using logistic regression models and the Wagstaff decomposition analysis.

RESULTS

Results provided by the two methods found a higher risk of cardiovascular diseases and diabetes in those with high socio-economic status in 2005. Similar results were observed in 2016. In 2016, the GSA showed that education level occupied the first place on the explanatory list of factors explaining 36.1% of the adult social inequality in high cardiovascular risk, followed by the area of residence (26.2%) and income (15.1%). Based on the Wagstaff decomposition analysis, the area of residence occupied the first place and explained 40.3% followed by income and education level explaining 19.2 and 14.0% respectively. Thus, both methods found similar factors explaining inequalities (income, educational level and regional conditions) but with different rankings of importance.

CONCLUSIONS

The present study showed substantial income-related inequalities in cardiovascular risk factors and diabetes in Tunisia and provided explanations for this. Results based on two different methods similarly showed that structural disparities on income, educational level and regional conditions should be addressed in order to reduce inequalities.

Impacts of post-Brexit agricultural policy on fruit and vegetable intake and cardiovascular disease

Background

The post-Brexit agricultural regime represents an opportunity to positively influence food systems and improve public health. Health-improving measures could include expanding the UK production of fruits and vegetables (F&V), thus increasing F&V availability. Currently, only 1.4% of total agricultural land in England is allocated to F&V. This study aims to estimate the potential impacts of allocating additional land to F&V production on cardiovascular disease (CVD) and inequalities in England between 2021 and 2030.

Methods

We used the previously validated IMPACT Food Policy model to translate changes in land allocated to F&V into changes in F&V intake and associated CVD mortality, expressed in number of deaths prevented or postponed (DPPs) by age, sex, and Index of Multiple Deprivation (IMD) quintile. We modelled two scenarios that assumed a linear increase in agricultural land allocated to F&V until it covers a) 10% and b) 20% of all land suitable for production of horticultural crops in England. We assumed that F&V prices would drop to a new equilibrium. We used Monte Carlo simulations to produce uncertainty intervals.

Results

Our model suggested that by 2030, F&V intake might increase by approximately 4% (95% Uncertainty Interval: 2%-7%) and 8% (4%-13%) respectively, under the first scenario. Under the second scenario, F&V intake could increase by approximately 17% (10%-29%) and 37% (26%-51%) respectively. These increases in F&V intake were associated with 3360 (1760-5920) CVD DPPs under the first scenario and 15700 (9000-24310) under the second scenario in 2021-2030. Our modelled scenarios could also reduce inequalities, with some 16% of DPPs occurring in the least deprived group compared with 22% in the most deprived.

Conclusions

Policymakers should consider the public health impacts of the post-Brexit agricultural regime in England. Increasing the land allocated to F&V production could substantially reduce the burden of CVD and associated inequalities.

Key messages

The post-Brexit agricultural policy can be an opportunity to improve diet and public health in the UK. Increasing the agricultural land allocated to fruit and vegetable production in England could reduce the burden of cardiovascular disease and associated inequalities.

Umbrella review of strategies to improve uptake of screening programmes

Introduction

High participation rates in screening programmes targeting non-communicable diseases are instrumental in achieving full screening benefits; however, screening programmes remain underused, especially among vulnerable populations. We conducted an umbrella review to assess the type of approaches screening programmes use to maximise uptake, the effectiveness of the approaches and the impact on equity.

Methods

Electronic databases were searched (1999-2019) for systematic reviews on approaches aimed at improving uptake of screening programmes for adults in middle- and high-income countries, with participation rate as the primary outcome. A narrative synthesis was undertaken to present the results by strategy, screening programme and strength of evidence. This study was registered in PROSPERO [CRD42019132087].

Results

In total, 3,059 records were identified, and 82 systematic reviews were included. Preliminary findings suggest contradictory evidence, and effectiveness appears to depend on the disease screened for and specific program implementation. Invitation methods including letters and direct reminders seem to work universally. However, combined approaches using access-enhancing, individual- and system-directed strategies seem to be more effective than single approaches such as invitation methods alone. Few studies evaluated the impact on equity.

Conclusions

Strategies to improve uptake of screening programmes have the potential to be effective. However, there are many components within the system, either at individual, health care professional or health care system level that can influence uptake of screening programmes. Within each screening programme, it is likely that a range of interventions is needed to improve the uptake as opposed to a single intervention.

Key messages

Improving uptake of screening programmes is a complex issue with many factors influencing the process. A range of interventions is favoured over single interventions.

Trends in Cardiometabolic Mortality in the United States, 1999-2017

This study evaluates the Centers for Disease Control and Prevention’s Wide-Ranging Online Data for Epidemiologic Research to compare trends in heart disease, stroke, diabetes, and hypertension mortality rates by race and sex from 1999 to 2017.

Comparative risk assessment of school food environment policies and childhood diets, childhood obesity, and future cardiometabolic mortality in the United States

BACKGROUND

Promising school policies to improve children's diets include providing fresh fruits and vegetables (F&V) and competitive food restrictions on sugar-sweetened beverages (SSBs), yet the impact of national implementation of these policies in US schools on cardiometabolic disease (CMD) risk factors and outcomes is not known. Our objective was to estimate the impact of national implementation of F&V provision and SSB restriction in US elementary, middle, and high schools on dietary intake and body mass index (BMI) in children and future CMD mortality.

METHODS

We used comparative risk assessment (CRA) frameworks to model the impacts of these policies with input parameters from nationally representative surveys, randomized-controlled trials, and systematic reviews and meta-analyses. For children ages 5-18 years, this incorporated national data on current dietary intakes and BMI, impacts of these policies on diet, and estimated effects of dietary changes on BMI. In adults ages 25 and older, we further incorporated the sustainability of dietary changes to adulthood, effects of dietary changes on CMD, and national CMD death statistics, modeling effects if these policies had been in place when current US adults were children. Uncertainty across inputs was incorporated using 1000 Monte Carlo simulations.

RESULTS

National F&V provision would increase daily fruit intake in children by as much as 25.0% (95% uncertainty interval (UI): 15.4, 37.7%), and would have small effects on vegetable intake. SSB restriction would decrease daily SSB intake by as much as 26.5% (95% UI: 6.4, 46.4%), and reduce BMI by as much as 0.7% (95% UI: 0.2, 1.2%). If F&V provision and SSB restriction were nationally implemented, an estimated 22,383 CMD deaths/year (95% UI: 18735, 25930) would be averted.

CONCLUSION

National school F&V provision and SSB restriction policies implemented in elementary, middle, and high schools could improve diet and BMI in children and reduce CMD mortality later in life.

Estimating the health and economic effects of the proposed US Food and Drug Administration voluntary sodium reformulation: Microsimulation cost-effectiveness analysis

BACKGROUND

Sodium consumption is a modifiable risk factor for higher blood pressure (BP) and cardiovascular disease (CVD). The US Food and Drug Administration (FDA) has proposed voluntary sodium reduction goals targeting processed and commercially prepared foods. We aimed to quantify the potential health and economic impact of this policy.

METHODS AND FINDINGS

We used a microsimulation approach of a close-to-reality synthetic population (US IMPACT Food Policy Model) to estimate CVD deaths and cases prevented or postponed, quality-adjusted life years (QALYs), and cost-effectiveness from 2017 to 2036 of 3 scenarios: (1) optimal, 100% compliance with 10-year reformulation targets; (2) modest, 50% compliance with 10-year reformulation targets; and (3) pessimistic, 100% compliance with 2-year reformulation targets, but with no further progress. We used the National Health and Nutrition Examination Survey and high-quality meta-analyses to inform model inputs. Costs included government costs to administer and monitor the policy, industry reformulation costs, and CVD-related healthcare, productivity, and informal care costs. Between 2017 and 2036, the optimal reformulation scenario achieving the FDA sodium reduction targets could prevent approximately 450,000 CVD cases (95% uncertainty interval: 240,000 to 740,000), gain approximately 2.1 million discounted QALYs (1.7 million to 2.4 million), and produce discounted cost savings (health savings minus policy costs) of approximately $41 billion ($14 billion to $81 billion). In the modest and pessimistic scenarios, health gains would be 1.1 million and 0.7 million QALYS, with savings of $19 billion and $12 billion, respectively. All the scenarios were estimated with more than 80% probability to be cost-effective (incremental cost/QALY < $100,000) by 2021 and to become cost-saving by 2031. Limitations include evaluating only diseases mediated through BP, while decreasing sodium consumption could have beneficial effects upon other health burdens such as gastric cancer. Further, the effect estimates in the model are based on interventional and prospective observational studies. They are therefore subject to biases and confounding that may have influenced also our model estimates.

CONCLUSIONS

Implementing and achieving the FDA sodium reformulation targets could generate substantial health gains and net cost savings.

IMPACT: A Generic Tool for Modelling and Simulating Public Health Policy

Background: Populations are under-served by local health policies and management of resources. This partly reflects a lack of realistically complex models to enable appraisal of a wide range of potential options. Rising computing power coupled with advances in machine learning and healthcare information now enables such models to be constructed and executed. However, such models are not generally accessible to public health practitioners who often lack the requisite technical knowledge or skills.

Objectives: To design and develop a system for creating, executing and analysing the results of simulated public health and health-care policy interventions, in ways that are accessible and usable by modellers and policy-makers.

Methods: The system requirements were captured and analysed in parallel with the statistical method development for the simulation engine. From the resulting software requirement specification the system architecture was designed, implemented and tested. A model for Coronary Heart Disease (CHD) was created and validated against empirical data.

Results: The system was successfully used to create and validate the CHD model. The initial validation results show concordance between the simulation results and the empirical data.

Conclusions: We have demonstrated the ability to connect health policy-modellers and policy-makers in a unified system, thereby making population health models easier to share, maintain, reuse and deploy.

Systematic review of dietary trans-fat reduction interventions

OBJECTIVE

To systematically review published studies of interventions to reduce people's intake of dietary trans-fatty acids (TFAs).

METHODS

We searched online databases (CINAHL, the CRD Wider Public Health database, Cochrane Database of Systematic Reviews, Ovid®, MEDLINE®, Science Citation Index and Scopus) for studies evaluating TFA interventions between 1986 and 2017. Absolute decrease in TFA consumption (g/day) was the main outcome measure. We excluded studies reporting only on the TFA content in food products without a link to intake. We included trials, observational studies, meta-analyses and modelling studies. We conducted a narrative synthesis to interpret the data, grouping studies on a continuum ranging from interventions targeting individuals to population-wide, structural changes.

RESULTS

After screening 1084 candidate papers, we included 23 papers: 12 empirical and 11 modelling studies. Multiple interventions in Denmark achieved a reduction in TFA consumption from 4.5 g/day in 1976 to 1.5 g/day in 1995 and then virtual elimination after legislation banning TFAs in manufactured food in 2004. Elsewhere, regulations mandating reformulation of food reduced TFA content by about 2.4 g/day. Worksite interventions achieved reductions averaging 1.2 g/day. Food labelling and individual dietary counselling both showed reductions of around 0.8 g/day.

CONCLUSION

Multicomponent interventions including legislation to eliminate TFAs from food products were the most effective strategy. Reformulation of food products and other multicomponent interventions also achieved useful reductions in TFA intake. By contrast, interventions targeted at individuals consistently achieved smaller reductions. Future prevention strategies should consider this effectiveness hierarchy to achieve the largest reductions in TFA consumption.

Comparing effectiveness of mass media campaigns with price reductions targeting fruit and vegetable intake on US cardiovascular disease mortality and race disparities

Background: A low intake of fruits and vegetables (F&Vs) is a major risk factor for cardiovascular disease (CVD) in the United States. Both mass media campaigns (MMCs) and economic incentives may increase F&V consumption. Few data exist on their comparative effectiveness.Objective: We estimated CVD mortality reductions potentially achievable by price reductions and MMC interventions targeting F&V intake in the US population.Design: We developed a US IMPACT Food Policy Model to compare 3 policies targeting F&V intake across US adults from 2015 to 2030: national MMCs and national F&V price reductions of 10% and 30%. We accounted for differences in baseline diets, CVD rates, MMC coverage, MMC duration, and declining effects over time. Outcomes included cumulative CVD (coronary heart disease and stroke) deaths prevented or postponed and life-years gained (LYGs) over the study period, stratified by age, sex, and race.Results: A 1-y MMC in 2015 would increase the average national F&V consumption by 7% for 1 y and prevent ∼18,600 CVD deaths (95% CI: 17,600, 19,500), gaining ∼280,100 LYGs by 2030. With a 15-y MMC, increased F&V consumption would be sustained, yielding a 3-fold larger reduction (56,100; 95% CI: 52,400, 57,700) in CVD deaths. In comparison, a 10% decrease in F&V prices would increase F&V consumption by ∼14%. This would prevent ∼153,300 deaths (95% CI: 146,400, 159,200), gaining ∼2.51 million LYGs. For a 30% price decrease, resulting in a 42% increase in F&V consumption, corresponding values would be 451,900 CVD deaths prevented or postponed (95% CI: 433,100, 467,500) and 7.3 million LYGs gained. Effects were similar by sex, with a smaller proportional effect and larger absolute effects at older ages. A 1-y MMC would be 35% less effective in preventing CVD deaths in non-Hispanic blacks than in whites. In comparison, price-reduction policies would have equitable proportional effects.Conclusion: Both national MMCs and price-reduction policies could reduce US CVD mortality, with price reduction being more powerful and sustainable.

Reducing US cardiovascular disease burden and disparities through national and targeted dietary policies: A modelling study

BACKGROUND

Large socio-economic disparities exist in US dietary habits and cardiovascular disease (CVD) mortality. While economic incentives have demonstrated success in improving dietary choices, the quantitative impact of different dietary policies on CVD disparities is not well established. We aimed to quantify and compare the potential effects on total CVD mortality and disparities of specific dietary policies to increase fruit and vegetable (F&V) consumption and reduce sugar-sweetened beverage (SSB) consumption in the US.

METHODS AND FINDINGS

Using the US IMPACT Food Policy Model and probabilistic sensitivity analyses, we estimated and compared the reductions in CVD mortality and socio-economic disparities in the US population potentially achievable from 2015 to 2030 with specific dietary policy scenarios: (a) a national mass media campaign (MMC) aimed to increase consumption of F&Vs and reduce consumption of SSBs, (b) a national fiscal policy to tax SSBs to increase prices by 10%, (c) a national fiscal policy to subsidise F&Vs to reduce prices by 10%, and (d) a targeted policy to subsidise F&Vs to reduce prices by 30% among Supplemental Nutrition Assistance Program (SNAP) participants only. We also evaluated a combined policy approach, combining all of the above policies. Data sources included the Surveillance, Epidemiology, and End Results Program, National Vital Statistics System, National Health and Nutrition Examination Survey, and published meta-analyses. Among the individual policy scenarios, a national 10% F&V subsidy was projected to be most beneficial, potentially resulting in approximately 150,500 (95% uncertainty interval [UI] 141,400-158,500) CVD deaths prevented or postponed (DPPs) by 2030 in the US. This far exceeds the approximately 35,100 (95% UI 31,700-37,500) DPPs potentially attributable to a 30% F&V subsidy targeting SNAP participants, the approximately 25,800 (95% UI 24,300-28,500) DPPs for a 1-y MMC, or the approximately 31,000 (95% UI 26,800-35,300) DPPs for a 10% SSB tax. Neither the MMC nor the individual national economic policies would significantly reduce CVD socio-economic disparities. However, the SNAP-targeted intervention might potentially reduce CVD disparities between SNAP participants and SNAP-ineligible individuals, by approximately 8% (10 DPPs per 100,000 population). The combined policy approach might save more lives than any single policy studied (approximately 230,000 DPPs by 2030) while also significantly reducing disparities, by approximately 6% (7 DPPs per 100,000 population). Limitations include our effect estimates in the model; these estimates use interventional and prospective observational studies (not exclusively randomised controlled trials). They are thus imperfect and should be interpreted as the best available evidence. Another key limitation is that we considered only CVD outcomes; the policies we explored would undoubtedly have additional beneficial effects upon other diseases. Further, we did not model or compare the cost-effectiveness of each proposed policy.

CONCLUSIONS

Fiscal strategies targeting diet might substantially reduce CVD burdens. A national 10% F&V subsidy would save by far the most lives, while a 30% F&V subsidy targeting SNAP participants would most reduce socio-economic disparities. A combined policy would have the greatest overall impact on both mortality and socio-economic disparities.

Systematic review of dietary salt reduction policies: Evidence for an effectiveness hierarchy?

BACKGROUND

Non-communicable disease (NCD) prevention strategies now prioritise four major risk factors: food, tobacco, alcohol and physical activity. Dietary salt intake remains much higher than recommended, increasing blood pressure, cardiovascular disease and stomach cancer. Substantial reductions in salt intake are therefore urgently needed. However, the debate continues about the most effective approaches. To inform future prevention programmes, we systematically reviewed the evidence on the effectiveness of possible salt reduction interventions. We further compared "downstream, agentic" approaches targeting individuals with "upstream, structural" policy-based population strategies.

METHODS

We searched six electronic databases (CDSR, CRD, MEDLINE, SCI, SCOPUS and the Campbell Library) using a pre-piloted search strategy focussing on the effectiveness of population interventions to reduce salt intake. Retrieved papers were independently screened, appraised and graded for quality by two researchers. To facilitate comparisons between the interventions, the extracted data were categorised using nine stages along the agentic/structural continuum, from "downstream": dietary counselling (for individuals, worksites or communities), through media campaigns, nutrition labelling, voluntary and mandatory reformulation, to the most "upstream" regulatory and fiscal interventions, and comprehensive strategies involving multiple components.

RESULTS

After screening 2,526 candidate papers, 70 were included in this systematic review (49 empirical studies and 21 modelling studies). Some papers described several interventions. Quality was variable. Multi-component strategies involving both upstream and downstream interventions, generally achieved the biggest reductions in salt consumption across an entire population, most notably 4g/day in Finland and Japan, 3g/day in Turkey and 1.3g/day recently in the UK. Mandatory reformulation alone could achieve a reduction of approximately 1.45g/day (three separate studies), followed by voluntary reformulation (-0.8g/day), school interventions (-0.7g/day), short term dietary advice (-0.6g/day) and nutrition labelling (-0.4g/day), but each with a wide range. Tax and community based counselling could, each typically reduce salt intake by 0.3g/day, whilst even smaller population benefits were derived from health education media campaigns (-0.1g/day). Worksite interventions achieved an increase in intake (+0.5g/day), however, with a very wide range. Long term dietary advice could achieve a -2g/day reduction under optimal research trial conditions; however, smaller reductions might be anticipated in unselected individuals.

CONCLUSIONS

Comprehensive strategies involving multiple components (reformulation, food labelling and media campaigns) and "upstream" population-wide policies such as mandatory reformulation generally appear to achieve larger reductions in population-wide salt consumption than "downstream", individually focussed interventions. This 'effectiveness hierarchy' might deserve greater emphasis in future NCD prevention strategies.

Explaining the Decline in Coronary Heart Disease Mortality in the Netherlands between 1997 and 2007

Objective

We set out to determine what proportion of the mortality decline from 1997 to 2007 in coronary heart disease (CHD) in the Netherlands could be attributed to advances in medical treatment and to improvements in population-wide cardiovascular risk factors.

Methods

We used the IMPACT-SEC model. Nationwide information was obtained on changes between 1997 and 2007 in the use of 42 treatments and in cardiovascular risk factor levels in adults, aged 25 or over. The primary outcome was the number of CHD deaths prevented or postponed.

Results

The age-standardized CHD mortality fell by 48% from 269 to 141 per 100.000, with remarkably similar relative declines across socioeconomic groups. This resulted in 11,200 fewer CHD deaths in 2007 than expected. The model was able to explain 72% of the mortality decline. Approximately 37% (95% CI: 10%-80%) of the decline was attributable to changes in acute phase and secondary prevention treatments: the largest contributions came from treating patients in the community with heart failure (11%) or chronic angina (9%). Approximately 36% (24%-67%) was attributable to decreases in risk factors: blood pressure (30%), total cholesterol levels (10%), smoking (5%) and physical inactivity (1%). Ten% more deaths could have been prevented if body mass index and diabetes would not have increased. Overall, these findings did not vary across socioeconomic groups, although within socioeconomic groups the contribution of risk factors differed.

Conclusion

CHD mortality has recently halved in The Netherlands. Equally large contributions have come from the increased use of acute and secondary prevention treatments and from improvements in population risk factors (including primary prevention treatments). Increases in obesity and diabetes represent a major challenge for future prevention policies.

Changes in Dietary Fat Intake and Projections for Coronary Heart Disease Mortality in Sweden: A Simulation Study

Objective

In Sweden, previous favourable trends in blood cholesterol levels have recently levelled off or even increased in some age groups since 2003, potentially reflecting changing fashions and attitudes towards dietary saturated fatty acids (SFA). We aimed to examine the potential effect of different SFA intake on future coronary heart disease (CHD) mortality in 2025.

Methods

We compared the effect on future CHD mortality of two different scenarios for fat intake a) daily SFA intake decreasing to 10 energy percent (E%), and b) daily SFA intake rising to 20 E%. We assumed that there would be moderate improvements in smoking (5%), salt intake (1g/day) and physical inactivity (5% decrease) to continue recent, positive trends.

Results

In the baseline scenario which assumed that recent mortality declines continue, approximately 5,975 CHD deaths might occur in year 2025. Anticipated improvements in smoking, dietary salt intake and physical activity, would result in some 380 (-6.4%) fewer deaths (235 in men and 145 in women). In combination with a mean SFA daily intake of 10 E%, a total of 810 (-14%) fewer deaths would occur in 2025 (535 in men and 275 in women). If the overall consumption of SFA rose to 20 E%, the expected mortality decline would be wiped out and approximately 20 (0.3%) additional deaths might occur.

Conclusion

CHD mortality may increase as a result of unfavourable trends in diets rich in saturated fats resulting in increases in blood cholesterol levels. These could cancel out the favourable trends in salt intake, smoking and physical activity.

Modelling Future Coronary Heart Disease Mortality to 2030 in the British Isles

Objective

Despite rapid declines over the last two decades, coronary heart disease (CHD) mortality rates in the British Isles are still amongst the highest in Europe. This study uses a modelling approach to compare the potential impact of future risk factor scenarios relating to smoking and physical activity levels, dietary salt and saturated fat intakes on future CHD mortality in three countries: Northern Ireland (NI), Republic of Ireland (RoI) and Scotland.

Methods

CHD mortality models previously developed and validated in each country were extended to predict potential reductions in CHD mortality from 2010 (baseline year) to 2030. Risk factor trends data from recent surveys at baseline were used to model alternative future risk factor scenarios: Absolute decreases in (i) smoking prevalence and (ii) physical inactivity rates of up to 15% by 2030; relative decreases in (iii) dietary salt intake of up to 30% by 2030 and (iv) dietary saturated fat of up to 6% by 2030. Probabilistic sensitivity analyses were then conducted.

Results

Projected populations in 2030 were 1.3, 3.4 and 3.9 million in NI, RoI and Scotland respectively (adults aged 25–84). In 2030: assuming recent declining mortality trends continue: 15% absolute reductions in smoking could decrease CHD deaths by 5.8–7.2%. 15% absolute reductions in physical inactivity levels could decrease CHD deaths by 3.1–3.6%. Relative reductions in salt intake of 30% could decrease CHD deaths by 5.2–5.6% and a 6% reduction in saturated fat intake might decrease CHD deaths by some 7.8–9.0%. These projections remained stable under a wide range of sensitivity analyses.

Conclusions

Feasible reductions in four cardiovascular risk factors (already achieved elsewhere) could substantially reduce future coronary deaths. More aggressive polices are therefore needed in the British Isles to control tobacco, promote healthy food and increase physical activity.

Quantifying the Socio-Economic Benefits of Reducing Industrial Dietary Trans Fats: Modelling Study

BACKGROUND

Coronary Heart Disease (CHD) remains a leading cause of UK mortality, generating a large and unequal burden of disease. Dietary trans fatty acids (TFA) represent a powerful CHD risk factor, yet to be addressed in the UK (approximately 1% daily energy) as successfully as in other nations. Potential outcomes of such measures, including effects upon health inequalities, have not been well quantified. We modelled the potential effects of specific reductions in TFA intake on CHD mortality, CHD related admissions, and effects upon socioeconomic inequalities.

METHODS & RESULTS

We extended the previously validated IMPACTsec model, to estimate the potential effects of reductions (0.5% & 1% reductions in daily energy) in TFA intake in England and Wales, stratified by age, sex and socioeconomic circumstances. We estimated reductions in expected CHD deaths in 2030 attributable to these two specific reductions. Output measures were deaths prevented or postponed, life years gained and hospital admissions. A 1% reduction in TFA intake energy intake would generate approximately 3,900 (95% confidence interval (CI) 3,300-4,500) fewer deaths, 10,000 (8,800-10,300) (7% total) fewer hospital admissions and 37,000 (30,100-44,700) life years gained. This would also reduce health inequalities, preventing five times as many deaths and gaining six times as many life years in the most deprived quintile compared with the most affluent. A more modest reduction (0.5%) would still yield substantial health gains.

CONCLUSIONS

Reducing intake of industrial TFA could substantially decrease CHD mortality and hospital admissions, and gain tens of thousands of life years. Crucially, this policy could also reduce health inequalities. UK strategies should therefore aim to minimise industrial TFA intake.

The Health Equity and Effectiveness of Policy Options to Reduce Dietary Salt Intake in England: Policy Forecast

BACKGROUND

Public health action to reduce dietary salt intake has driven substantial reductions in coronary heart disease (CHD) over the past decade, but avoidable socio-economic differentials remain. We therefore forecast how further intervention to reduce dietary salt intake might affect the overall level and inequality of CHD mortality.

METHODS

We considered English adults, with socio-economic circumstances (SEC) stratified by quintiles of the Index of Multiple Deprivation. We used IMPACTSEC, a validated CHD policy model, to link policy implementation to salt intake, systolic blood pressure and CHD mortality. We forecast the effects of mandatory and voluntary product reformulation, nutrition labelling and social marketing (e.g., health promotion, education). To inform our forecasts, we elicited experts' predictions on further policy implementation up to 2020. We then modelled the effects on CHD mortality up to 2025 and simultaneously assessed the socio-economic differentials of effect.

RESULTS

Mandatory reformulation might prevent or postpone 4,500 (2,900-6,100) CHD deaths in total, with the effect greater by 500 (300-700) deaths or 85% in the most deprived than in the most affluent. Further voluntary reformulation was predicted to be less effective and inequality-reducing, preventing or postponing 1,500 (200-5,000) CHD deaths in total, with the effect greater by 100 (-100-600) deaths or 49% in the most deprived than in the most affluent. Further social marketing and improvements to labelling might each prevent or postpone 400-500 CHD deaths, but minimally affect inequality.

CONCLUSIONS

Mandatory engagement with industry to limit salt in processed-foods appears a promising and inequality-reducing option. For other policy options, our expert-driven forecast warns that future policy implementation might reach more deprived individuals less well, limiting inequality reduction. We therefore encourage planners to prioritise equity.

Decline in Coronary Mortality in Sweden between 1986 and 2002: Comparing Contributions from Primary and Secondary Prevention

Background

The relative importance of risk factor reduction in healthy people (primary prevention) versus that in patients with coronary heart disease (secondary prevention) has been debated. We aimed to quantify the contribution of the two.

Methodology

We used the previously validated IMPACT model to estimate contributions from primary prevention (reducing risk factors in the population, particularly smoking, cholesterol and systolic blood pressure) and from secondary prevention (reducing risk factors in coronary heart disease patients) in the Swedish population.

Principal Findings

Between 1986 and 2002, about 8,690 fewer deaths were related to changes in the three major risk factors. Population cholesterol fell by 0.64 mmol/L, with approximately 5,210 fewer deaths attributable to diet changes (4,470 in healthy people740 in patients.) plus 810 to statin treatment (200 in healthy people, 610 in patients). Overall smoking prevalence decreased by 10.3%, resulting in 1,195 fewer deaths, attributable to smoking cessation (595 in healthy people, 600 in patients). Mean population systolic blood pressure fell by 2.6 mmHg, resulting in 900 fewer deaths (865 in healthy people, 35 in patients), plus 575 fewer deaths attributable to antihypertensive medication in healthy people. The majority of falls in deaths attributable to risk factors occurred in people without known heart disease: 6,705 fewer deaths compared with 1,985 fewer deaths in patients (secondary prevention), emphasizing the importance of promoting health interventions in the general population.

Conclusions

The largest effects on mortality came from primary prevention, giving markedly larger mortality reductions than secondary prevention.

Quantifying the contribution of statins to the decline in population mean cholesterol by socioeconomic group in England 1991 - 2012: a modelling study

Background

Serum total cholesterol is one of the major targets for cardiovascular disease prevention. Statins are effective for cholesterol control in individual patients. At the population level, however, their contribution to total cholesterol decline remains unclear. The aim of this study was to quantify the contribution of statins to the observed fall in population mean cholesterol levels in England over the past two decades, and explore any differences between socioeconomic groups.

Methods and Findings

This is a modelling study based on data from the Health Survey for England. We analysed changes in observed mean total cholesterol levels in the adult England population between 1991-92 (baseline) and 2011-12. We then compared the observed changes with a counterfactual ‘no statins’ scenario, where the impact of statins on population total cholesterol was estimated and removed. We estimated uncertainty intervals (UI) using Monte Carlo simulation, where confidence intervals (CI) were impractical. In 2011-12, 13.2% (95% CI: 12.5-14.0%) of the English adult population used statins at least once per week, compared with 1991-92 when the proportion was just 0.5% (95% CI: 0.3-1.0%). Between 1991-92 and 2011-12, mean total cholesterol declined from 5.86 mmol/L (95% CI: 5.82-5.90) to 5.17 mmol/L (95% CI: 5.14-5.20). For 2011-12, mean total cholesterol was lower in more deprived groups. In our ‘no statins’ scenario we predicted a mean total cholesterol of 5.36 mmol/L (95% CI: 5.33-5.40) for 2011-12. Statins were responsible for approximately 33.7% (95% UI: 28.9-38.8%) of the total cholesterol reduction since 1991-92. The statin contribution to cholesterol reduction was greater among the more deprived groups of women, while showing little socio-economic gradient among men.

Conclusions

Our model suggests that statins explained around a third of the substantial falls in total cholesterol observed in England since 1991. Approximately two thirds of the cholesterol decrease can reasonably be attributed non-pharmacological determinants.