A method for the inclusion of physical activity-related health benefits in cost-benefit analysis of built environment initiatives

The built environment has a significant influence on population levels of physical activity (PA) and therefore health. However, PA-related health benefits are seldom considered in transport and urban planning (i.e. built environment interventions) cost-benefit analysis. Cost-benefit analysis implies that the benefits of any initiative are valued in monetary terms to make them commensurable with costs. This leads to the need for monetised values of the health benefits of PA. The aim of this study was to explore a method for the incorporation of monetised PA-related health benefits in cost-benefit analysis of built environment interventions. Firstly, we estimated the change in population level of PA attributable to a change in the built environment due to the intervention. Then, changes in population levels of PA were translated into monetary values. For the first step we used estimates from the literature for the association of built environment features with physical activity outcomes. For the second step we used the multi-cohort proportional multi-state life table model to predict changes in health-adjusted life years and health care costs as a function of changes in PA. Finally, we monetised health-adjusted life years using the value of a statistical life year. Future research could adapt these methods to assess the health and economic impacts of specific urban development scenarios by working in collaboration with urban planners.

A shift from motorised travel to active transport: What are the potential health gains for an Australian city?

INTRODUCTION

An alarmingly high proportion of the Australian adult population does not meet national physical activity guidelines (57%). This is concerning because physical inactivity is a risk factor for several chronic diseases. In recent years, an increasing emphasis has been placed on the potential for transport and urban planning to contribute to increased physical activity via greater uptake of active transport (walking, cycling and public transport). In this study, we aimed to estimate the potential health gains and savings in health care costs of an Australian city achieving its stated travel targets for the use of active transport.

METHODS

Additional active transport time was estimated for the hypothetical scenario of Brisbane (1.1 million population 2013) in Australia achieving specified travel targets. A multi-state life table model was used to estimate the number of health-adjusted life years, life-years, changes in the burden of diseases and injuries, and the health care costs associated with changes in physical activity, fine particle (<2.5 μm; PM2.5) exposure, and road trauma attributable to a shift from motorised travel to active transport. Sensitivity analyses were conducted to test alternative modelling assumptions.

RESULTS

Over the life course of the Brisbane adult population in 2013 (860,000 persons), 33,000 health-adjusted life years could be gained if the travel targets were achieved by 2026. This was mainly due to lower risks of physical inactivity-related diseases, with life course reductions in prevalence and mortality risk in the range of 1.5%-6.0%. Prevalence and mortality of respiratory diseases increased slightly (≥0.27%) due to increased exposure of larger numbers of cyclists and pedestrians to fine particles. The burden of road trauma increased by 30% for mortality and 7% for years lived with disability. We calculated substantial net savings ($AU183 million, 2013 values) in health care costs.

CONCLUSION

In cities, such as Brisbane, where over 80% of trips are made by private cars, shifts towards walking, cycling and public transport would cause substantial net health benefits and savings in health care costs. However, for such shifts to occur, investments are needed to ensure safe and convenient travel.

Processes of care in surgical patients who died with hospital-acquired infections in Australian hospitals

BACKGROUND

Infection may complicate surgical patients' hospital admission. The effect of hospital-acquired infections (HAIs) on processes of care among surgical patients who died is unknown.

AIM

To investigate the effect of HAIs on processes of care in surgical patients who died in hospital.

METHODS

Surgeon-recorded infection data extracted from a national Australian surgical mortality audit (2012-2016) were grouped into HAIs and no infection. The audit included all-age surgical patients, who died in hospital. Not all patients had surgery. Excluded from analysis were patients with community-acquired infection and those with missing timing of infection. Multivariate logistic regression was used to determine the adjusted effects of HAIs on the processes of care in these patients. Costs associated with HAIs were estimated.

FINDINGS

One-fifth of surgical patients who died did so with an HAI (2242 out of 11,681; 19.2%). HAI patients had increased processes of care compared to those who died without infection: postoperative complications [51.0% vs 30.3%; adjusted odds ratio (aOR): 2.20; 95% confidence interval (CI): 1.98-2.45; P < 0.001]; unplanned reoperations (22.6% vs 10.9%; aOR: 2.38; 95% CI: 2.09-2.71; P < 0.001) and unplanned intensive care unit admission (29.3% vs 14.8%; aOR: 2.18; 95% CI: 1.94-2.45; P < 0.001). HAI patients had longer hospital admissions and greater hospital costs than those without infection.

CONCLUSION

HAIs were associated with increased processes of care and costs in surgical patients who died; these outcomes need to be investigated in surgical patients who survive.

Population awareness of cardiovascular disease and its risk factors in Buea, Cameroon

Background

Adequate awareness of cardiovascular diseases (CVD) and their risk factors may help reduce the population’s exposure to modifiable risk factors and thereby contribute to prevention and control strategies. There is limited data on knowledge among the general population in sub-Saharan Africa regarding CVD and risk factors. We aimed to assess the population awareness (and associated factors) of CVD types and risk factors in Buea, Cameroon.

Methods

This was a community-based cross-sectional study conducted in 2016 among randomly selected adults (>18 years). Data on socio-demographic characteristics, knowledge about CVD types, their risk factors and warning signs for CVD events (stroke and heart attack) were acquired using a self-administered questionnaire. Logistic regression analysis was used to investigate factors associated with moderate-to-good knowledge.

Results

Of the 1162 participants (61.7% women, mean age 32 years), 52.5% had overall poor knowledge (mean score 12.1 on total of 25) on CVD with only about a quarter correctly identifying types of CVD. Overall, 36, 63 and 45% were unaware of CVD risk factors, warning signs of heart attack and stroke respectively. In multivariable analysis; high level of education (aOR = 2.26 (1.69–3.02), p < 0.0001), high monthly income (aOR = 1.64 (1.07–2.51), p = 0.023), having a family history of CVD (aOR = 1.59 (1.21–2.09), p = 0.001) and being a former smoker (aOR = 1.11 (1.02–1.95), p = 0.043) were associated with moderate-to-good knowledge.

Conclusions

There exists a significant gap in population awareness about CVDs in Cameroon and this is similar to previous reports. Cost-effective community health education interventions taking into account socioeconomic status may be beneficial in this setting.

The impact on productivity of a hypothetical tax on sugar-sweetened beverages

OBJECTIVES

To quantify the potential impact of an additional 20% tax on sugar-sweetened beverages (SSBs) on productivity in Australia.

METHODS

We used a multi-state lifetable Markov model to examine the potential impact of an additional 20% tax on SSBs on total lifetime productivity in the paid and unpaid sectors of the economy. The study population consisted of Australians aged 20 years or older in 2010, whose health and other relevant outcomes were modelled over their remaining lifetime.

RESULTS

The SSBs tax was estimated to reduce the number of people with obesity by 1.96% of the entire population (437,000 fewer persons with obesity), and reduce the number of employees with obesity by 317,000 persons. These effects translated into productivity gains in the paid sector of AU$751 million for the working-age population (95% confidence interval: AU$565 million to AU$954 million), using the human capital approach. In the unpaid sector, the potential productivity gains amounted to AU$1172 million (AU$929 million to AU$1435 million) using the replacement cost method. These productivity benefits are in addition to the health benefits of 35,000 life years gained and a reduction in healthcare costs of AU$425 million.

CONCLUSIONS

An additional 20% tax on SSBs not only improves health outcomes and reduces healthcare costs, but provides productivity gains in both the paid and unpaid sectors of the economy.

Active transport and obesity prevention - A transportation sector obesity impact scoping review and assessment for Melbourne, Australia

Given the alarming prevalence of obesity worldwide and the need for interventions to halt the growing epidemic, more evidence on the role and impact of transport interventions for obesity prevention is required. This study conducts a scoping review of the current evidence of association between modes of transport (motor vehicle, walking, cycling and public transport) and obesity-related outcomes. Eleven reviews and thirty-three primary studies exploring associations between transport behaviours and obesity were identified. Cohort simulation Markov modelling was used to estimate the effects of body mass index (BMI) change on health outcomes and health care costs of diseases causally related to obesity in the Melbourne, Australia population. Results suggest that evidence for an obesity effect of transport behaviours is inconclusive (29% of published studies reported expected associations, 33% mixed associations), and any potential BMI effect is likely to be relatively small. Hypothetical scenario analyses suggest that active transport interventions may contribute small but significant obesity-related health benefits across populations (approximately 65 health adjusted life years gained per year). Therefore active transport interventions that are low cost and targeted to those most amenable to modal switch are the most likely to be effective and cost-effective from an obesity prevention perspective. The uncertain but potentially significant opportunity for health benefits warrants the collection of more and better quality evidence to fully understand the potential relationships between transport behaviours and obesity. Such evidence would contribute to the obesity prevention dialogue and inform policy across the transportation, health and environmental sectors.

Body mass index-measured adiposity and population attributability of associated factors: a population-based study from Buea, Cameroon

Background

Obesity is currently a global health challenge driven by a mix of behavioural, environmental and genetic factors. Up to date population-based disease burden estimates are needed to guide successful prevention and control efforts in African countries. We investigated the prevalence and population attributable fractions of overweight and obesity in Buea, the Southwest region of Cameroon.

Methods

Data are from a community-based cross-sectional study involving randomly selected adults conducted in 2016. Body mass index (BMI) was categorized according to the WHO classification. Multivariable logistic regressions were used to investigate factors independently associated with obesity. Corresponding population attributable fractions were estimated.

Results

Among the 1,139 participants, age-standardized prevalence (95% CI) of overweight and obesity were; 36.5 (33.7–39.3) and 11.1 (9.3–12.9) percent respectively. Mean BMI was 25.3 ± 4.3 kg/m²; women were heavier than men (25.8 vs. 24.4 kg/m²; p <0.0001). Factors associated with obesity were; female gender [odds ratio 3.20 (95% CI: 1.93–5.59)], age > 31 years [3.21 (1.86–5.28)] and being married [2.10 (1.60–3.51)]. At the population level; older age, being married, low level of education, high monthly income and physical inactivity accounted respectively for 11.9%, 21.8%, 11.6%, 6.4% and 8.7% of overweight and obesity among the women, while older age and being married explained 9.2% and 28.3% of overweight and obesity in men.

Conclusion

The prevalence of overweight and obesity in this semi-urban Cameroonian population is high, affecting over a third of individuals. Community-based interventions to control weight would need to take into account gender specificities and socio-economic status.

Living well after breast cancer randomized controlled trial protocol: evaluating a telephone-delivered weight loss intervention versus usual care in women following treatment for breast cancer

BACKGROUND

Obesity, physical inactivity and poor diet quality have been associated with increased risk of breast cancer-specific and all-cause mortality as well as treatment-related side-effects in breast cancer survivors. Weight loss intervention trials in breast cancer survivors have shown that weight loss is safe and achievable; however, few studies have examined the benefits of such interventions on a broad range of outcomes and few have examined factors important to translation (e.g. feasible delivery method for scaling up, assessment of sustained changes, cost-effectiveness). The Living Well after Breast Cancer randomized controlled trial aims to evaluate a 12-month telephone-delivered weight loss intervention (versus usual care) on weight change and a range of secondary outcomes including cost-effectiveness.

METHODS/DESIGN

Women (18-75 years; body mass index 25-45 kg/m2) diagnosed with stage I-III breast cancer in the previous 2 years are recruited from public and private hospitals and through the state-based cancer registry (target n = 156). Following baseline assessment, participants are randomized 1:1 to either a 12-month telephone-delivered weight loss intervention (targeting diet and physical activity) or usual care. Data are collected at baseline, 6-months (mid-intervention), 12-months (end-of-intervention) and 18-months (maintenance). The primary outcome is change in weight at 12-months. Secondary outcomes are changes in body composition, bone mineral density, cardio-metabolic and cancer-related biomarkers, metabolic health and chronic disease risk, physical function, patient-reported outcomes (quality of life, fatigue, menopausal symptoms, body image, fear of cancer recurrence) and behaviors (dietary intake, physical activity, sitting time). Data collected at 18-months will be used to assess whether outcomes achieved at end-of-intervention are sustained six months after intervention completion. Cost-effectiveness will be assessed, as will mediators and moderators of intervention effects.

DISCUSSION

This trial will provide evidence needed to inform the wide-scale provision of weight loss, physical activity and dietary interventions as part of routine survivorship care for breast cancer survivors.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trial Registry (ANZCTR) - ACTRN12612000997853 (Registered 18 September 2012).

Measuring the health-related Sustainable Development Goals in 188 countries: a baseline analysis from the Global Burden of Disease Study 2015

BACKGROUND

In September, 2015, the UN General Assembly established the Sustainable Development Goals (SDGs). The SDGs specify 17 universal goals, 169 targets, and 230 indicators leading up to 2030. We provide an analysis of 33 health-related SDG indicators based on the Global Burden of Diseases, Injuries, and Risk Factors Study 2015 (GBD 2015).

METHODS

We applied statistical methods to systematically compiled data to estimate the performance of 33 health-related SDG indicators for 188 countries from 1990 to 2015. We rescaled each indicator on a scale from 0 (worst observed value between 1990 and 2015) to 100 (best observed). Indices representing all 33 health-related SDG indicators (health-related SDG index), health-related SDG indicators included in the Millennium Development Goals (MDG index), and health-related indicators not included in the MDGs (non-MDG index) were computed as the geometric mean of the rescaled indicators by SDG target. We used spline regressions to examine the relations between the Socio-demographic Index (SDI, a summary measure based on average income per person, educational attainment, and total fertility rate) and each of the health-related SDG indicators and indices.

FINDINGS

In 2015, the median health-related SDG index was 59·3 (95% uncertainty interval 56·8-61·8) and varied widely by country, ranging from 85·5 (84·2-86·5) in Iceland to 20·4 (15·4-24·9) in Central African Republic. SDI was a good predictor of the health-related SDG index (r2=0·88) and the MDG index (r2=0·92), whereas the non-MDG index had a weaker relation with SDI (r2=0·79). Between 2000 and 2015, the health-related SDG index improved by a median of 7·9 (IQR 5·0-10·4), and gains on the MDG index (a median change of 10·0 [6·7-13·1]) exceeded that of the non-MDG index (a median change of 5·5 [2·1-8·9]). Since 2000, pronounced progress occurred for indicators such as met need with modern contraception, under-5 mortality, and neonatal mortality, as well as the indicator for universal health coverage tracer interventions. Moderate improvements were found for indicators such as HIV and tuberculosis incidence, minimal changes for hepatitis B incidence took place, and childhood overweight considerably worsened.

INTERPRETATION

GBD provides an independent, comparable avenue for monitoring progress towards the health-related SDGs. Our analysis not only highlights the importance of income, education, and fertility as drivers of health improvement but also emphasises that investments in these areas alone will not be sufficient. Although considerable progress on the health-related MDG indicators has been made, these gains will need to be sustained and, in many cases, accelerated to achieve the ambitious SDG targets. The minimal improvement in or worsening of health-related indicators beyond the MDGs highlight the need for additional resources to effectively address the expanded scope of the health-related SDGs.

FUNDING

Bill & Melinda Gates Foundation.

Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015

BACKGROUND

The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context.

METHODS

We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors-the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI).

FINDINGS

Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25%. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25% over the same period. All risks jointly evaluated in 2015 accounted for 57·8% (95% CI 56·6-58·8) of global deaths and 41·2% (39·8-42·8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211·8 million [192·7 million to 231·1 million] global DALYs), smoking (148·6 million [134·2 million to 163·1 million]), high fasting plasma glucose (143·1 million [125·1 million to 163·5 million]), high BMI (120·1 million [83·8 million to 158·4 million]), childhood undernutrition (113·3 million [103·9 million to 123·4 million]), ambient particulate matter (103·1 million [90·8 million to 115·1 million]), high total cholesterol (88·7 million [74·6 million to 105·7 million]), household air pollution (85·6 million [66·7 million to 106·1 million]), alcohol use (85·0 million [77·2 million to 93·0 million]), and diets high in sodium (83·0 million [49·3 million to 127·5 million]). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa.

INTERPRETATION

Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden.

FUNDING

Bill & Melinda Gates Foundation.

Cost-effectiveness of investing in sidewalks as a means of increasing physical activity: a RESIDE modelling study

BACKGROUND

Studies consistently find that supportive neighbourhood built environments increase physical activity by encouraging walking and cycling. However, evidence on the cost-effectiveness of investing in built environment interventions as a means of promoting physical activity is lacking. In this study, we assess the cost-effectiveness of increasing sidewalk availability as one means of encouraging walking.

METHODS

Using data from the RESIDE study in Perth, Australia, we modelled the cost impact and change in health-adjusted life years (HALYs) of installing additional sidewalks in established neighbourhoods. Estimates of the relationship between sidewalk availability and walking were taken from a previous study. Multistate life table models were used to estimate HALYs associated with changes in walking frequency and duration. Sensitivity analyses were used to explore the impact of variations in population density, discount rates, sidewalk costs and the inclusion of unrelated healthcare costs in added life years.

RESULTS

Installing and maintaining an additional 10 km of sidewalk in an average neighbourhood with 19 000 adult residents was estimated to cost A$4.2 million over 30 years and gain 24 HALYs over the lifetime of an average neighbourhood adult resident population. The incremental cost-effectiveness ratio was A$176 000/HALY. However, sensitivity results indicated that increasing population densities improves cost-effectiveness.

CONCLUSIONS

In low-density cities such as in Australia, installing sidewalks in established neighbourhoods as a single intervention is unlikely to cost-effectively improve health. Sidewalks must be considered alongside other complementary elements of walkability, such as density, land use mix and street connectivity. Population density is particularly important because at higher densities, more residents are exposed and this improves the cost-effectiveness. Health gain is one of many benefits of enhancing neighbourhood walkability and future studies might consider a more comprehensive assessment of its social value (eg, social cohesion, safety and air quality).

Physical activity and risk of breast cancer, colon cancer, diabetes, ischemic heart disease, and ischemic stroke events: systematic review and dose-response meta-analysis for the Global Burden of Disease Study 2013

OBJECTIVE

 To quantify the dose-response associations between total physical activity and risk of breast cancer, colon cancer, diabetes, ischemic heart disease, and ischemic stroke events.

DESIGN

 Systematic review and Bayesian dose-response meta-analysis.

DATA SOURCES

 PubMed and Embase from 1980 to 27 February 2016, and references from relevant systematic reviews. Data from the Study on Global AGEing and Adult Health conducted in China, Ghana, India, Mexico, Russia, and South Africa from 2007 to 2010 and the US National Health and Nutrition Examination Surveys from 1999 to 2011 were used to map domain specific physical activity (reported in included studies) to total activity.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

 Prospective cohort studies examining the associations between physical activity (any domain) and at least one of the five diseases studied.

RESULTS

 174 articles were identified: 35 for breast cancer, 19 for colon cancer, 55 for diabetes, 43 for ischemic heart disease, and 26 for ischemic stroke (some articles included multiple outcomes). Although higher levels of total physical activity were significantly associated with lower risk for all outcomes, major gains occurred at lower levels of activity (up to 3000-4000 metabolic equivalent (MET) minutes/week). For example, individuals with a total activity level of 600 MET minutes/week (the minimum recommended level) had a 2% lower risk of diabetes compared with those reporting no physical activity. An increase from 600 to 3600 MET minutes/week reduced the risk by an additional 19%. The same amount of increase yielded much smaller returns at higher levels of activity: an increase of total activity from 9000 to 12 000 MET minutes/week reduced the risk of diabetes by only 0.6%. Compared with insufficiently active individuals (total activity <600 MET minutes/week), the risk reduction for those in the highly active category (≥8000 MET minutes/week) was 14% (relative risk 0.863, 95% uncertainty interval 0.829 to 0.900) for breast cancer; 21% (0.789, 0.735 to 0.850) for colon cancer; 28% (0.722, 0.678 to 0.768) for diabetes; 25% (0.754, 0.704 to 0.809) for ischemic heart disease; and 26% (0.736, 0.659 to 0.811) for ischemic stroke.

CONCLUSIONS

 People who achieve total physical activity levels several times higher than the current recommended minimum level have a significant reduction in the risk of the five diseases studied. More studies with detailed quantification of total physical activity will help to find more precise relative risk estimates for different levels of activity.

The association between built environment features and physical activity in the Australian context: a synthesis of the literature

BACKGROUND

There is growing evidence indicating that the built environment is a determinant of physical activity. However, despite the well-established health benefits of physical activity this is rarely considered in urban planning. We summarised recent Australian evidence for the association built environment-physical activity among adults. This summary aims to inform policy makers who advocate for the consideration of health in urban planning.

METHODS

A combination of built environment and physical activity terms were used to systematically identify relevant peer reviewed and grey literature.

RESULTS

A total of 23 studies were included, providing 139 tests of associations between specific built environment features and physical activity. Of the total, 84 relationships using objective measures of built environment attributes were evaluated, whereas 55 relationships using self-reported measures were evaluated. Our results indicate that walkable neighbourhoods with a wide range of local destinations to go to, as well as a diverse use of land, encourage physical activity among their residents.

CONCLUSIONS

This research provides a summary of recent Australian evidence on built environments that are most favourable for physical activity. Features of walkability and availability of destinations within walking distance should be accounted for in the development or redevelopment of urban areas. Our findings emphasise the importance of urban planning for health via its impact on population levels of physical activity.

Dietary fats: a new look at old data challenges established wisdom

Replacing saturated fat with polyunsaturated fat might not prolong life

Decreasing the Burden of Type 2 Diabetes in South Africa: The Impact of Taxing Sugar-Sweetened Beverages

INTRODUCTION

Type 2 diabetes poses an increasing public health burden in South Africa (SA) with obesity as the main driver of the epidemic. Consumption of sugar sweetened beverages (SSBs) is linked to weight gain and reducing SSB consumption may significantly impact the prevalence of obesity and related diseases. We estimated the effect of a 20% SSB tax on the burden of diabetes in SA.

METHODS AND FINDINGS

We constructed a life table-based model in Microsoft Excel (2010). Consumption data from the 2012 SA National Health and Nutrition Examination Survey, previously published own- and cross-price elasticities of SSBs and energy balance equations were used to estimate changes in daily energy intake and its projected impact on BMI arising from increased SSB prices. Diabetes relative risk and prevalent years lived with disability estimates from the Global Burden of Disease Study and modelled disease epidemiology estimates from a previous study were used to estimate the effect of the BMI changes on diabetes burden. Diabetes cost estimates were obtained from the South African Council for Medical Schemes. Over 20 years, a 20% SSB tax could reduce diabetes incident cases by 106 000 in women (95% uncertainty interval (UI) 70 000-142 000) and by 54 000 in men (95% UI: 33 000-80 000); and prevalence in all adults by 4.0% (95% UI: 2.7%-5.3%). Cumulatively over twenty years, approximately 21 000 (95% UI: 14 000-29 000) adult T2DM-related deaths, 374 000 DALYs attributed to T2DM (95% UI: 299 000-463 000) and over ZAR10 billion T2DM healthcare costs (95% UI: ZAR6.8-14.0 billion) equivalent to USD860 million (95% UI: USD570 million-USD1.2 billion) may be averted.

CONCLUSION

Fiscal policy on SSBs has the potential to mitigate the diabetes epidemic in South Africa and contribute to the National Department of Health goals stated in the National NCD strategic plan.

Depression prevention, labour force participation and income of older working aged Australians: A microsimulation economic analysis

OBJECTIVE

Depression has economic consequences not only for the health system, but also for individuals and society. This study aims to quantify the potential economic impact of five-yearly screening for sub-syndromal depression in general practice among Australians aged 45-64 years, followed by a group-based psychological intervention to prevent progression to depression.

METHOD

We used an epidemiological simulation model to estimate reductions in prevalence of depression, and a microsimulation model, Health&WealthMOD2030, to estimate the impact on labour force participation, personal income, savings, taxation revenue and welfare expenditure.

RESULTS

Group therapy is estimated to prevent around 5,200 prevalent cases of depression (2.2%) and add about 520 people to the labour force. Private incomes are projected to increase by $19 million per year, tax revenues by $2.4 million, and transfer payments are reduced by $2.6 million.

CONCLUSION

Group-based psychological intervention to prevent depression could result in considerable economic benefits in addition to its clinical effects.

Global, regional, and national prevalence of overweight and obesity in children and adults during 1980-2013: a systematic analysis for the Global Burden of Disease Study 2013

BACKGROUND

In 2010, overweight and obesity were estimated to cause 3·4 million deaths, 3·9% of years of life lost, and 3·8% of disability-adjusted life-years (DALYs) worldwide. The rise in obesity has led to widespread calls for regular monitoring of changes in overweight and obesity prevalence in all populations. Comparable, up-to-date information about levels and trends is essential to quantify population health effects and to prompt decision makers to prioritise action. We estimate the global, regional, and national prevalence of overweight and obesity in children and adults during 1980-2013.

METHODS

We systematically identified surveys, reports, and published studies (n=1769) that included data for height and weight, both through physical measurements and self-reports. We used mixed effects linear regression to correct for bias in self-reports. We obtained data for prevalence of obesity and overweight by age, sex, country, and year (n=19,244) with a spatiotemporal Gaussian process regression model to estimate prevalence with 95% uncertainty intervals (UIs).

FINDINGS

Worldwide, the proportion of adults with a body-mass index (BMI) of 25 kg/m(2) or greater increased between 1980 and 2013 from 28·8% (95% UI 28·4-29·3) to 36·9% (36·3-37·4) in men, and from 29·8% (29·3-30·2) to 38·0% (37·5-38·5) in women. Prevalence has increased substantially in children and adolescents in developed countries; 23·8% (22·9-24·7) of boys and 22·6% (21·7-23·6) of girls were overweight or obese in 2013. The prevalence of overweight and obesity has also increased in children and adolescents in developing countries, from 8·1% (7·7-8·6) to 12·9% (12·3-13·5) in 2013 for boys and from 8·4% (8·1-8·8) to 13·4% (13·0-13·9) in girls. In adults, estimated prevalence of obesity exceeded 50% in men in Tonga and in women in Kuwait, Kiribati, Federated States of Micronesia, Libya, Qatar, Tonga, and Samoa. Since 2006, the increase in adult obesity in developed countries has slowed down.

INTERPRETATION

Because of the established health risks and substantial increases in prevalence, obesity has become a major global health challenge. Not only is obesity increasing, but no national success stories have been reported in the past 33 years. Urgent global action and leadership is needed to help countries to more effectively intervene.

FUNDING

Bill & Melinda Gates Foundation.

Global, regional, and national prevalence of overweight and obesity in children and adults during 1980-2013: a systematic analysis for the Global Burden of Disease Study 2013

BACKGROUND

In 2010, overweight and obesity were estimated to cause 3·4 million deaths, 3·9% of years of life lost, and 3·8% of disability-adjusted life-years (DALYs) worldwide. The rise in obesity has led to widespread calls for regular monitoring of changes in overweight and obesity prevalence in all populations. Comparable, up-to-date information about levels and trends is essential to quantify population health effects and to prompt decision makers to prioritise action. We estimate the global, regional, and national prevalence of overweight and obesity in children and adults during 1980-2013.

METHODS

We systematically identified surveys, reports, and published studies (n=1769) that included data for height and weight, both through physical measurements and self-reports. We used mixed effects linear regression to correct for bias in self-reports. We obtained data for prevalence of obesity and overweight by age, sex, country, and year (n=19,244) with a spatiotemporal Gaussian process regression model to estimate prevalence with 95% uncertainty intervals (UIs).

FINDINGS

Worldwide, the proportion of adults with a body-mass index (BMI) of 25 kg/m(2) or greater increased between 1980 and 2013 from 28·8% (95% UI 28·4-29·3) to 36·9% (36·3-37·4) in men, and from 29·8% (29·3-30·2) to 38·0% (37·5-38·5) in women. Prevalence has increased substantially in children and adolescents in developed countries; 23·8% (22·9-24·7) of boys and 22·6% (21·7-23·6) of girls were overweight or obese in 2013. The prevalence of overweight and obesity has also increased in children and adolescents in developing countries, from 8·1% (7·7-8·6) to 12·9% (12·3-13·5) in 2013 for boys and from 8·4% (8·1-8·8) to 13·4% (13·0-13·9) in girls. In adults, estimated prevalence of obesity exceeded 50% in men in Tonga and in women in Kuwait, Kiribati, Federated States of Micronesia, Libya, Qatar, Tonga, and Samoa. Since 2006, the increase in adult obesity in developed countries has slowed down.

INTERPRETATION

Because of the established health risks and substantial increases in prevalence, obesity has become a major global health challenge. Not only is obesity increasing, but no national success stories have been reported in the past 33 years. Urgent global action and leadership is needed to help countries to more effectively intervene.

FUNDING

Bill & Melinda Gates Foundation.

Does physical activity prevent cognitive decline and dementia?: A systematic review and meta-analysis of longitudinal studies

BACKGROUND

By 2050, it has been estimated that approximately one-fifth of the population will be made up of older adults (aged ≥60 years). Old age often comes with cognitive decline and dementia. Physical activity may prevent cognitive decline and dementia.

METHODS

We reviewed and synthesised prospective studies into physical activity and cognitive decline, and physical activity and dementia, published until January 2014. Forty-seven cohorts, derived from two previous systematic reviews and an updated database search, were used in the meta-analyses. Included participants were aged ≥40 years, in good health and/or randomly selected from the community. Studies were assessed for methodological quality.

RESULTS

Twenty-one cohorts on physical activity and cognitive decline and twenty-six cohorts on physical activity and dementia were included. Meta-analysis, using the quality-effects model, suggests that participants with higher levels of physical activity, when compared to those with lower levels, are at reduced risk of cognitive decline, RR 0.65, 95% CI 0.55-0.76, and dementia, RR 0.86, 95% CI 0.76-0.97. Sensitivity analyses revealed a more conservative estimate of the impact of physical activity on cognitive decline and dementia for high quality studies, studies reporting effect sizes as ORs, greater number of adjustments (≥10), and longer follow-up time (≥10 years). When one heavily weighted study was excluded, physical activity was associated with an 18% reduction in the risk of dementia (RR 0.82; 0.73-0.91).

CONCLUSIONS

Longitudinal observational studies show an association between higher levels of physical activity and a reduced risk of cognitive decline and dementia. A case can be made for a causal interpretation. Future research should use objective measures of physical activity, adjust for the full range of confounders and have adequate follow-up length. Ideally, randomised controlled trials will be conducted. Regardless of any effect on cognition, physical activity should be encouraged, as it has been shown to be beneficial on numerous levels.

Improving diet and physical activity to reduce population prevalence of overweight and obesity: an overview of current evidence

OBJECTIVE

The aim of this study is to provide an overview of interventions to reduce or prevent overweight or obesity and improve diet or physical activity.

METHODS

A review of meta-analyses and/or systematic reviews of these interventions in any setting or age group were conducted. Narrative systematic reviews were included for intervention categories with limited meta-analyses available. Summary measures including weighted mean difference, standardised mean difference, and I-squared, were examined.

RESULTS

A total of 60 meta-analyses and 23 systematic reviews met the inclusion criteria. Dietary interventions and multi-component interventions targeting overweight and obesity appeared to have the greatest effects, particularly in comparison with workplace or technology or internet-based interventions. Pharmaceutical and surgical interventions produced favourable results for specific population sub-groups (i.e. morbidly obese). Population-wide strategies such as policy interventions have not been widely analysed. The effectiveness of the interventions to assist in maintaining behaviour or weight change remains unclear.

CONCLUSIONS

Various individually targeted interventions were shown to reduce body weight, although effect sizes were typically modest, and the durability of effects has been questioned. New approaches to evaluating population-based interventions, such as taxes and regulation, are recommended. Future research modelling the long-term effects of interventions across the lifespan would also be beneficial.