Bayesian strategy selection identifies optimal solutions to complex problems using an example from GP prescribing.

Complex health problems require multi-strategy, multi-target interventions. We present a method that uses machine learning techniques to choose optimal interventions from a set of possible interventions within a case study aiming to increase General Practitioner (GP) discussions of physical activity (PA) with their patients. Interventions were developed based on a causal loop diagram with 26 GPs across 13 clinics in Geelong, Australia. GPs prioritised eight from more than 80 potential interventions to increase GP discussion of PA with patients. Following a 2-week baseline, a multi-arm bandit algorithm was used to assign optimal strategies to GP clinics with the target outcome being GP PA discussion rates. The algorithm was updated weekly and the process iterated until the more promising strategies emerged (a duration of seven weeks). The top three performing strategies were continued for 3 weeks to improve the power of the hypothesis test of effectiveness for each strategy compared to baseline. GPs recorded a total of 11,176 conversations about PA. GPs identified 15 factors affecting GP PA discussion rates with patients including GP skills and awareness, fragmentation of care and fear of adverse outcomes. The two most effective strategies were correctly identified within seven weeks of the algorithm-based assignment of strategies. These were clinic reception staff providing PA information to patients at check in and PA screening questionnaires completed in the waiting room. This study demonstrates an efficient way to test and identify optimal strategies from multiple possible solutions.

Comparing complex perspectives on obesity drivers: action-driven communities and evidence-oriented experts.

INTRODUCTION: The Foresight obesity map represents an expert-developed systems map describing the complex drivers of obesity. Recently, community-led causal loop diagrams have been developed to support community-based obesity prevention interventions. This paper presents a quantitative comparison between the Foresight obesity systems map and a community-developed map of the drivers of obesity. METHODS: Variables from a community-developed map were coded against the thematic clusters defined in the Foresight map to allow comparison of their sizes and strength of adjoining causal relationships. Central variables were identified using techniques from network analysis. These properties were compared to understand the similarities and differences between the systems as defined by the two groups. RESULTS: The community map focused on environmental influences, such as built physical activity environment (18% of variables) and social psychology (38%). The Foresight map's largest cluster was physiology (23%), a minimal focus in the community map (2%). Network analysis highlighted media and available time within both maps, but variables related to school and sporting club environments were unique to the community map. CONCLUSION: Community stakeholders focus on modifiable social and environmental drivers of obesity. Capturing local perspectives is critical when using systems maps to guide community-based obesity prevention.

Evaluation of complex community-based childhood obesity prevention interventions.

BACKGROUND: Multi-setting, multi-component community-based interventions have shown promise in preventing childhood obesity; however, evaluation of these complex interventions remains a challenge. OBJECTIVE: The objective of the study is to systematically review published methodological approaches to outcome evaluation for multi-setting community-based childhood obesity prevention interventions and synthesize a set of pragmatic recommendations. METHODS: MEDLINE, CINAHL and PsycINFO were searched from inception to 6 July 2017. Papers were included if the intervention targeted children ≤18 years, engaged at least two community sectors and described their outcome evaluation methodology. A single reviewer conducted title and abstract scans, full article review and data abstraction. Directed content analysis was performed by three reviewers to identify prevailing themes. RESULTS: Thirty-three studies were included, and of these, 26 employed a quasi-experimental design; the remaining were randomized control trials. Body mass index was the most commonly measured outcome, followed by health behaviour change and psychosocial outcomes. Six themes emerged, highlighting advantages and disadvantages of active vs. passive consent, quasi-experimental vs. randomized control trials, longitudinal vs. repeat cross-sectional designs and the roles of process evaluation and methodological flexibility in evaluating complex interventions. CONCLUSIONS: Selection of study designs and outcome measures compatible with community infrastructure, accompanied by process evaluation, may facilitate successful outcome evaluation.

Sustaining obesity prevention in communities: a systematic narrative synthesis review.

Obesity is a global problem for which sustainable solutions are yet to be realized. Community-based interventions have improved obesity-related behaviours and obesity in the short term. Few papers have explored how to make the interventions and their intended outcomes sustainable. The aim of this paper is to identify factors that contribute to the sustainability of community-based obesity prevention interventions and their intended outcomes. A systematic narrative synthesis review was conducted of published community-based obesity prevention interventions to identify factors contributing to intervention sustainability. Data extracted were included study authors' perspectives of intervention success and sustainability. Eighty-one papers met the inclusion criteria, and from these we identified ten factors that contribute to sustainability: resourcing, leadership, workforce development, community engagement, partnerships, policy, communications, adaptability, evaluation and governance. This review of community-based obesity prevention interventions gives rise to optimism that sustainable change is possible. We propose a framework to help practitioners build sustainability into their interventions and report on them so that others can also benefit.

Associations between obesogenic risk and depressive symptomatology in Australian adolescents: a cross-sectional study.

BACKGROUND: Depression and obesity are significant health concerns currently facing adolescents worldwide. This paper investigates the associations between obesity and related risk behaviours and depressive symptomatology in an Australian adolescent population. METHODS: Data from the Australian Capital Territory It's Your Move project, an Australian community-based intervention project were used. In 2012, 800 students (440 females, 360 males) aged 11-14 years (M=13.11 years, SD=0.62 years), from 6 secondary schools were weighed and measured and completed a questionnaire which included physical activity, sedentary behaviour and dietary intake. Weight status was defined by WHO criteria. A cut-off score ≥10 on the Short Mood and Feelings Questionnaire indicated symptomatic depression. Logistic regression was used to test associations. RESULTS: After controlling for potential confounders, results showed significantly higher odds of depressive symptomatology in males (OR=1.22, p<0.05) and females (OR=1.12, p<0.05) who exceeded guidelines for daily screen-time leisure sedentary activities. Higher odds of depressive symptoms were seen in females who consumed greater amounts of sweet drink (OR=1.18, p<0.05), compared to lower female consumers of sweet drinks, and males who were overweight/obese also had greater odds of depressive symptoms (OR=1.83, p<0.05) compared to male normal weight adolescents. CONCLUSIONS: This study demonstrates the associations between obesogenic risks and depression in adolescents. Further research should explore the direction of these associations and identify common determinants of obesity and depression. Mental health outcomes need to be included in the rationale and evaluation for diet and activity interventions.

Associations between obesogenic risk factors and depression among adolescents: a systematic review.

Adolescence is a transitional life phase that is associated with heightened risk for two major health conditions - obesity and mental health problems. Given the established comorbidity of obesity and depression, one avenue that warrants further exploration is the association between obesogenic risk and obesity in the expression and maintenance of depressive symptoms. The aim of the current systematic review was to identify and evaluate the empirical literature reporting the relationships between obesogenic risk factors (physical activity, sedentary behaviour, diet and weight status) and depression in adolescents. A search of five databases for studies published over the last decade found 24 studies eligible for review. Relationships were found between lack of physical exercise, heightened sedentary behaviour, poor diet quality, obese or overweight and depression in adolescence. However, the finding that obesogenic risk factors are associated with poor adolescent mental health should be interpreted with caution as data typically come from non-representative samples with less than optimal study design and methodology.

Inconsistent associations between sweet drink intake and 2-year change in BMI among Victorian children and adolescents.

OBJECTIVE: The aim of this study was to examine whether baseline (T1) or 2-year change in sweet drink intake in children and adolescents was associated with age- and gender-standardized body mass index (BMIz) at time two (T2), 2 years later. METHODS: Data on 1465 children and adolescents from the comparison groups of two quasi-experimental intervention studies from Victoria, Australia were analysed. At two time points between 2003 and 2008 (mean interval: 2.2 years) height and weight were measured and sweet drink consumption (soft drink and fruit juice/cordial) was assessed. RESULTS: No association was observed between T1 sweet drink intake and BMIz at T2 among children or adolescents. Children from higher socioeconomic status families who reported an increased intake of sweet drinks at T2 compared with T1 had higher mean BMIz at T2 (ß: 0.13, P = 0.05). There was no evidence of a dose-response relationship between sweet drink intake and BMIz. In supplementary analyses, we observed that more frequent usual consumption of fruit juice/cordial was associated with a higher BMIz at T2 among children. CONCLUSION: This study showed limited evidence of an association between sweet drink intake and BMIz. However, the association is complex and may be confounded by both dietary and activity behaviours.

The possibility of regulating for obesity prevention--understanding regulation in the Commonwealth Government.

A complex regulatory package is likely to be necessary to effectively reduce obesity prevalence in developed countries. This study investigated the barriers and facilitators to implementing regulatory interventions to prevent obesity within the executive arm of the Australian Commonwealth Government. Policy reviews were conducted on nine government departments to understand their roles and interests in obesity. From this process we identified regulatory review carried out by the Office of Best Practice Regulation as possibly posing a barrier to law reform for obesity prevention, along with the complexity of the food policymaking structures. The policy reviews informed subsequent in-depth semi-structured interviews with senior Commonwealth government officers (n = 13) focused on refining our understanding of the barriers to enacting obesity prevention policy. In addition to the two barriers already identified, interviewees identified a lack of evidence for interventions, which would reduce obesity prevalence, and the influence of politicians on executive decisions as posing obstacles. Most interviewees believed that the barriers to regulating to prevent obesity were strong and that intervention by elected politicians would be the most likely method of implementing obesity prevention policy.

The appropriateness of opt-out consent for monitoring childhood obesity in Australia.

Childhood obesity monitoring is a fundamental component of obesity prevention but is poorly done in Australia. Monitoring obesity prevalence in children provides important population health data that can be used to track trends over time, identify areas at greatest risk of obesity, determine the effectiveness of interventions and policies, raise awareness and stimulate action. High participation rates are essential for effective monitoring because these provide more representative data. Passive ('opt-out') consent has been shown to provide high participation rates in international childhood obesity monitoring programs and in a recent Australian federal initiative monitoring early child development. A federal initiative structured like existing child development monitoring programs, but with the authority to collect height and weight measurements using opt-out consent, is recommended to monitor rates of childhood obesity in Australia.

Modelling the health impact of environmentally sustainable dietary scenarios in the UK.

BACKGROUND/OBJECTIVES: Food is responsible for around one-fifth of all greenhouse gas (GHG) emissions from products consumed in the UK, the largest contributor of which is meat and dairy. The Committee on Climate Change have modelled the impact on GHG emissions of three dietary scenarios for food consumption in the UK. This paper models the impact of the three scenarios on mortality from cardiovascular disease and cancer. SUBJECTS/METHODS: A previously published model (DIETRON) was used. The three scenarios were parameterised by fruit and vegetables, fibre, total fat, saturated fat, monounsaturated fatty acids, polyunsaturated fatty acids, cholesterol and salt using the 2008 Family Food Survey. A Monte Carlo simulation generated 95% credible intervals. RESULTS: Scenario 1 (50% reduction in meat and dairy replaced by fruit, vegetables and cereals: 19% reduction in GHG emissions) resulted in 36,910 (30,192 to 43,592) deaths delayed or averted per year. Scenario 2 (75% reduction in cow and sheep meat replaced by pigs and poultry: 9% reduction in GHG emissions) resulted in 1999 (1739 to 2389) deaths delayed or averted. Scenario 3 (50% reduction in pigs and poultry replaced with fruit, vegetables and cereals: 3% reduction in GHG emissions) resulted in 9297 (7288 to 11,301) deaths delayed or averted. CONCLUSION: Modelled results suggest that public health and climate change dietary goals are in broad alignment with the largest results in both domains occurring when consumption of all meat and dairy products are reduced. Further work in real-life settings is needed to confirm these results.

Government regulation to promote healthy food environments--a view from inside state governments.

Food policy interventions are an important component of obesity-prevention strategies and can potentially drive positive changes in obesogenic environments. This study sought to identify regulatory interventions targeting the food environment, and barriers/facilitators to their implementation at the Australian state government level. In-depth interviews were conducted with senior representatives from state/territory governments, statutory authorities and non-government organizations (n =45) to examine participants' (i) suggestions for regulatory interventions for healthier food environments and (ii) support for pre-selected regulatory interventions derived from a literature review. Data were analysed using thematic and constant comparative analyses. Interventions commonly suggested by participants were regulating unhealthy food marketing; limiting the density of fast food outlets; pricing reforms to decrease fruit/vegetable prices and increase unhealthy food prices; and improved food labelling. The most commonly supported pre-selected interventions were related to food marketing and service. Primary production and retail sector interventions were least supported. The dominant themes were the need for whole-of-government and collaborative approaches; the influence of the food industry; conflicting policies/agenda; regulatory challenges; the need for evidence of effectiveness; and economic disincentives. While interventions such as public sector healthy food service policies were supported by participants, marketing restrictions and fiscal interventions face substantial barriers including a push for deregulation and private sector opposition.

[Population-level changes to promote cardiovascular health]. / Zmeny na úrovni populace zamerené na podporu kardiovaskulárního zdraví

BACKGROUND: Cardiovascular diseases (CVD) cause 1.8 million premature (<75 years) death annually in Europe. The majority of these deaths are preventable with the most efficient and cost-effective approach being on the population level. The aim of this position paper is to assist authorities in selecting the most adequate management strategies to prevent CVD. DESIGN AND METHODS: Experts reviewed and summarized the published evidence on the major modifiable CVD risk factors: food, physical inactivity, smoking, and alcohol. Population-based preventive strategies focus on fiscal measures (e.g. taxation), national and regional policies (e.g. smoke-free legislation), and environmental changes (e.g. availability of alcohol). RESULTS: Food is a complex area, but several strategies can be effective in increasing fruit and vegetables and lowering intake of salt, saturated fat, trans-fats, and free sugars. Tobacco and alcohol can be regulated mainly by fiscal measures and national policies, but local availability also plays a role. Changes in national policies and the built environment will integrate physical activity into daily life. CONCLUSION: Societal changes and commercial influences have led to the present unhealthy environment, in which default option in life style increases CVD risk. A challenge for both central and local authorities is, therefore, to ensure healthier defaults. This position paper summarizes the evidence and recommends a number of structural strategies at international, national, and regional levels that in combination can substantially reduce CVD.

An index of unhealthy lifestyle is associated with coronary heart disease mortality rates for small areas in England after adjustment for deprivation.

Indices of socio-economic deprivation are often used as a proxy for differences in the health behaviours of populations within small areas, but these indices are a measure of the economic environment rather than the health environment. Sets of synthetic estimates of the ward-level prevalence of low fruit and vegetable consumption, obesity, raised blood pressure, raised cholesterol and smoking were combined to develop an index of unhealthy lifestyle. Multi-level regression models showed that this index described about 50% of the large-scale geographic variation in CHD mortality rates in England, and substantially adds to the ability of an index of deprivation to explain geographic variations in CHD mortality rates.

Best practice principles for community-based obesity prevention: development, content and application.

Best practice in obesity prevention has generally been defined in terms of 'what' needs to be done while neglecting 'how'. A multifaceted definition of best practice, which combines available evidence on what actions to take, with an established process for interpreting this information in a specific community context, provides a more appropriate basis for defining the principles of best practice in community-based obesity prevention. Based on analysis of a range of literature, a preliminary set of principles was drafted and progressively revised through further analyses of published literature and a series of consultations. The framework for best practice principles comprises: community engagement, programme design and planning, evaluation, implementation and sustainability, and governance. Specific principles were formulated within this framework. While many principles were generic, distinctive features of obesity prevention were also covered. The engagement of end-users influenced the design of the formatting of the outputs, which represent three levels of knowledge transfer: detailed evidence summaries, guiding questions for programme planners and a briefer set of questions for simpler communication purposes. The best practice principles provide a valuable mechanism for the translation of existing evidence and experience into the decision-making processes for planning, implementing and evaluating the complex community-based interventions needed for successful obesity prevention.

The burden of smoking-related ill health in the UK.

BACKGROUND: Smoking is one of the biggest avoidable causes of morbidity and mortality in the United Kingdom. This paper quantifies the current health and economic burden of smoking in the UK. It provides comparisons with previous studies of the burden of smoking in the UK and with the costs for other chronic disease risk factors. METHODS: A systematic literature review to identify previous estimates of National Health Service costs attributable to smoking was undertaken. Information from the World Health Organization's Global Burden of Disease Project and routinely collected mortality data were used to calculate mortality due to smoking in the UK. Population-attributable fractions for smoking-related diseases from the Global Burden of Disease Project were applied to NHS cost data to estimate direct financial costs. RESULTS: Previous studies estimated that smoking costs the NHS about 1.4 billion to 1.7 billion pound in 1991 and has been responsible for about 100,000 deaths per annum over the past 10 years. This paper estimates that the number of deaths attributable to smoking in 2005 was 109,164 (19% of all deaths, 27% deaths in men and 11% of deaths in women). Smoking was directly responsible for 12% of disability adjusted life years lost in 2002 (15.4% in men; 8.5% in women) and the direct cost to the NHS was 5.2 billion pound in 2005-6. CONCLUSION: Smoking is still a considerable public health burden in the UK. Accurately establishing the burden in terms of death, disability and financial costs is important for informing national public health policy.

Coronary heart disease trends in England and Wales from 1984 to 2004: concealed levelling of mortality rates among young adults.

BACKGROUND: Trends in cardiovascular risk factors among UK adults present a complex picture. Ominous increases in obesity and diabetes among young adults raise concerns about subsequent coronary heart disease (CHD) mortality rates in this group. OBJECTIVE: To examine recent trends in age-specific mortality rates from CHD, particularly those among younger adults. METHODS AND RESULTS: Mortality data from 1984 to 2004 were used to calculate age-specific mortality rates for British adults aged 35+ years, and joinpoint regression was used to assess changes in trends. Overall, the age-adjusted mortality rate decreased by 54.7% in men and by 48.3% in women. However, among men aged 35-44 years, CHD mortality rates in 2002 increased for the first time in over two decades. Furthermore, the recent declines in CHD mortality rates seem to be slowing in both men and women aged 45-54. Among older adults, however, mortality rates continued to decrease steadily throughout the period. CONCLUSIONS: The flattening mortality rates for CHD among younger adults may represent a sentinel event. Deteriorations in medical management of CHD appear implausible. Thus, unfavourable trends in risk factors for CHD, specifically obesity and diabetes, provide the most likely explanation for the observed trends.

The burden of overweight and obesity-related ill health in the UK.

This paper reviews previous cost studies of overweight and obesity in the UK. It proposes a method for estimating the economic and health costs of overweight and obesity in the UK which could also be used in other countries. Costs of obesity studies were identified via a systematic search of electronic databases. Information from the WHO Burden of Disease Project was used to calculate the mortality and morbidity cost of overweight and obesity. Population attributable fractions for diseases attributable to overweight and obesity were applied to National Health Service (NHS) cost data to estimate direct financial costs. We estimate the direct cost of overweight and obesity to the NHS at pound 3.2 billion. Other estimates of the cost of obesity range between pound 480 million in 1998 and pound 1.1 billion in 2004 [Correction added after online publication 11 June 2007: 'of the cost of obesity' added after 'Other estimates']. There is wide variation in methods and estimates for the cost of overweight and obesity to the health systems of developed countries. The method presented here could be used to calculate the costs of overweight and obesity in other countries. Public health initiatives are required to address the increasing prevalence of overweight and obesity and reduce associated healthcare costs.

Occupational health needs of universities: a review with an emphasis on the United Kingdom.

This study describes the needs of universities in relation to planning the provision of occupational health services, by detailing their occupational hazards and risks and other relevant factors. The paper presents the results of (1) an enquiry into publicly available data relevant to occupational health in the university sector in the United Kingdom, (2) a literature review on occupational health provision in universities, and (3) selected results from a survey of university occupational health services in the UK. Although the enquiry and survey, but not the literature review, were restricted to the UK, the authors consider that the results are relevant to other countries because of the broad similarities of the university sector between countries. These three approaches showed that the university sector is large, with a notably wide range of occupational hazards, and other significant factors which must be considered in planning occupational health provision for individual universities or for the sector as a whole.