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Mireille E Schnitzer - One of the best experts on this subject based on the ideXlab platform.
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educational note paradoxical collider effect in the analysis of Non Communicable Disease epidemiological data a reproducible illustration and web application
International Journal of Epidemiology, 2019Co-Authors: Miguel Angel Luquefernandez, Michael Schomaker, Daniel Redondosanchez, Maria Jose Sanchez Perez, Anand Vaidya, Mireille E SchnitzerAbstract:Classical epidemiology has focused on the control of confounding, but it is only recently that epidemiologists have started to focus on the bias produced by colliders. A collider for a certain pair of variables (e.g. an outcome Y and an exposure A) is a third variable (C) that is caused by both. In a directed acyclic graph (DAG), a collider is the variable in the middle of an inverted fork (i.e. the variable C in A → C ← Y). Controlling for, or conditioning an analysis on a collider (i.e. through stratification or regression) can introduce a spurious association between its causes. This potentially explains many paradoxical findings in the medical literature, where established risk factors for a particular outcome appear protective. We use an example from Non-Communicable Disease epidemiology to contextualize and explain the effect of conditioning on a collider. We generate a dataset with 1000 observations, and run Monte-Carlo simulations to estimate the effect of 24-h dietary sodium intake on systolic blood pressure, controlling for age, which acts as a confounder, and 24-h urinary protein excretion, which acts as a collider. We illustrate how adding a collider to a regression model introduces bias. Thus, to prevent paradoxical associations, epidemiologists estimating causal effects should be wary of conditioning on colliders. We provide R code in easy-to-read boxes throughout the manuscript, and a GitHub repository [https://github.com/migariane/ColliderApp] for the reader to reproduce our example. We also provide an educational web application allowing real-time interaction to visualize the paradoxical effect of conditioning on a collider [http://watzilei.com/shiny/collider/].
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educational note paradoxical collider effect in the analysis of Non Communicable Disease epidemiological data a reproducible illustration and web application
arXiv: Methodology, 2018Co-Authors: Miguel Angel Luquefernandez, Michael Schomaker, Daniel Redondosanchez, Maria Jose Sanchez Perez, Anand Vaidya, Mireille E SchnitzerAbstract:Classical epidemiology has focused on the control of confounding but it is only recently that epidemiologists have started to focus on the bias produced by colliders. A collider for a certain pair of variables (e.g., an outcome Y and an exposure A) is a third variable (C) that is caused by both. In a directed acyclic graph (DAG), a collider is the variable in the middle of an inverted fork (i.e., the variable C in A -> C <- Y). Controlling for, or conditioning an analysis on a collider (i.e., through stratification or regression) can introduce a spurious association between its causes. This potentially explains many paradoxical findings in the medical literature, where established risk factors for a particular outcome appear protective. We use an example from Non-Communicable Disease epidemiology to contextualize and explain the effect of conditioning on a collider. We generate a dataset with 1,000 observations and run Monte-Carlo simulations to estimate the effect of 24-hour dietary sodium intake on systolic blood pressure, controlling for age, which acts as a confounder, and 24-hour urinary protein excretion, which acts as a collider. We illustrate how adding a collider to a regression model introduces bias. Thus, to prevent paradoxical associations, epidemiologists estimating causal effects should be wary of conditioning on colliders. We provide R-code in easy-to-read boxes throughout the manuscript and a GitHub repository (this https URL) for the reader to reproduce our example. We also provide an educational web application allowing real-time interaction to visualize the paradoxical effect of conditioning on a collider this http URL.
Luke Allen - One of the best experts on this subject based on the ideXlab platform.
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estimating the impact of achieving turkey s Non Communicable Disease policy targets a macro simulation modelling study
The Lancet Regional health. Europe, 2021Co-Authors: Joao Breda, Luke Allen, Birol Tibet, Toker Erguder, Erdem Karabulut, Hasan Huseyin Yildirim, Alexander Mok, Kremlin WickramasingheAbstract:Summary Background The Burden of Non-Communicable Disease (NCDs) has continued to rise globally, particularly in low- and middle-income countries. In Turkey, NCDs account for 89% of all deaths, with nearly one in five deaths occurring before age 70. This study investigates the number of NCD deaths that could be prevented if Turkey met national and international targets for major modifiable NCD risk factors. Methods Preventable deaths were estimated using the World Health Organization (WHO) ‘Preventable Risk Integrated ModEl’ (PRIME), by combining: 1) Baseline exposure data for risk factors, referenced from national surveillance and cohort studies; 2) Aetiological associations from published meta-analyses; and 3) Demographic and mortality statistics obtained from the Turkish Statistical Institute (TurkStat). Confidence intervals were estimated using Monte Carlo simulations. Findings If Turkey met its NCD risk factor targets for reducing tobacco and salt consumption by 30%, and physical inactivity by 10% in 2017, an estimated 19,859 deaths (95%CI: 12,802 to 26,609) could have been prevented. Approximately two thirds of these preventable deaths were in men, and one in three were in adults below 75 years. A 30% relative reduction in the consumption of alcohol, tobacco, and salt, as well as physical inactivity, would prevent 180 (107 to 259); 4,786 (3,679 to 5,836); 13,112 (5,819 to 19,952); and 7,124 (5,053 to 9,212) deaths, respectively. Interpretation Among major modifiable NCD risk factors, population-level reductions in salt intake and physical inactivity present the greatest opportunity for reducing NCD mortality in Turkey. These findings can help Turkey prioritise interventions to meet the Sustainable Development Goal target of reducing NCD mortality by one third, by 2030.
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implementation of Non Communicable Disease policies a geopolitical analysis of 151 countries
The Lancet Global Health, 2020Co-Authors: Luke Allen, Brian D Nicholson, Beatrice Y T Yeung, Francisco GoianadasilvaAbstract:Summary Background Most countries have endorsed WHO Non-Communicable Disease (NCD) best buy policies, but we know very little about global implementation patterns and about the geopolitical factors affecting implementation. We aimed to assess global implementation based on analysis of multiple geopolitical datasets. Methods We used the 2015 and 2017 WHO NCD progress monitor reports to calculate aggregate implementation scores for 151 countries, based on their implementation of 18 WHO-recommended NCD policies. We ranked all countries and used descriptive statistics to analyse global trends. We used linear regression to assess the associations between policy implementation and World Bank geographic region, risk of premature NCD mortality, percentage of all deaths caused by NCDs, World Bank income group, human capital index, democracy index, and tax burden. Findings In 2017, the mean NCD policy implementation score was 49·3% (SD 18·4%). Costa Rica and Iran had the joint-highest implementation scores (86·1% of all WHO-recommended policies). Scores were lowest in Haiti and South Sudan (5·5%). Between 2015 and 2017, aggregate implementation scores rose in 109 countries and regressed in 32 countries. Mean implementation rose for all of the 18 policies except for those targeting alcohol and physical activity. The most commonly implemented policies were clinical guidelines, graphic warnings on tobacco packaging, and NCD risk factor surveys. Our multiple linear regression model explained 61·1% of the variance in 2017 aggregate scores (p Interpretation Implementation of WHO-recommended NCD policies is increasing over time. On average, countries implemented just under half of the NCD policies recommended by WHO in 2017. Nutrition-related policies saw gains, while those related to alcohol and physical activity were the most likely to have been dropped. Aggregate implementation scores tended to be highest in high-income countries that invest in health care and education. Funding National Institute for Health Research, Imperial College London, University of Oxford.
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financing national Non Communicable Disease responses
Global Health Action, 2017Co-Authors: Luke AllenAbstract:Non-Communicable Diseases (NCDs) (also known as socially transmitted Diseases) were conspicuously absent from the Millennium Development Goals and seemed to miss out on the 'golden years' of health funding despite causing more death and disability than any other Disease group worldwide. The share of 'development assistance for health' dedicated to NCDs has remained at 1-2% of the total since 2000. This level of funding is insufficient to attain the nine targets in the World Health Organization (WHO) Global Action Plan on NCDs. In 2015 the Sustainable Development Goals - which include the target of reducing premature NCD mortality by a third - were endorsed by 193 countries. Whilst this commitment is welcome, the same text stresses the primacy of domestic financing, which is currently dominated by out-of-pocket payments in low- and middle-income countries (LMICs). This paper presents the findings of the WHO Global Coordination Mechanism on NCDs financing working group. The group was convened to explore NCD financing options with an emphasis on LMICs. The main sources of available finance include taxation, loans, engagement with the private sector, impact investment and innovative financing mechanisms. There is a role for development assistance to increase in the interim as raising additional revenue from these sources will take time. In the medium term it may be appropriate for international NCD funding to remain low where LMICs successfully assume financial responsibility for preventing and controlling NCDs. Countries will have to manage blends of innovative and traditional funding sources, whilst finding ways to boost tax revenue for NCDs.
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socioeconomic status and Non Communicable Disease behavioural risk factors in low income and lower middle income countries a systematic review
The Lancet Global Health, 2017Co-Authors: Luke Allen, Julianne Williams, Nick Townsend, Bente Mikkelsen, Nia Roberts, Charlie Foster, Kremlin WickramasingheAbstract:Summary Background Non-Communicable Diseases are the leading global cause of death and disproportionately afflict those living in low-income and lower-middle-income countries (LLMICs). The association between socioeconomic status and Non-Communicable Disease behavioural risk factors is well established in high-income countries, but it is not clear how behavioural risk factors are distributed within LLMICs. We aimed to systematically review evidence on the association between socioeconomic status and harmful use of alcohol, tobacco use, unhealthy diets, and physical inactivity within LLMICs. Methods We searched 13 electronic databases, including Embase and MEDLINE, grey literature, and reference lists for primary research published between Jan 1, 1990, and June 30, 2015. We included studies from LLMICs presenting data on multiple measures of socioeconomic status and tobacco use, alcohol use, diet, and physical activity. No age or language restrictions were applied. We excluded studies that did not allow comparison between more or less advantaged groups. We used a piloted version of the Cochrane Effective Practice and Organisation of Care Group data collection checklist to extract relevant data at the household and individual level from the included full text studies including study type, methods, outcomes, and results. Due to high heterogeneity, we used a narrative approach for data synthesis. We used descriptive statistics to assess whether the prevalence of each risk factor varied significantly between members of different socioeconomic groups. The study protocol is registered with PROSPERO, number CRD42015026604. Findings After reviewing 4242 records, 75 studies met our inclusion criteria, representing 2 135 314 individuals older than 10 years from 39 LLMICs. Low socioeconomic groups were found to have a significantly higher prevalence of tobacco and alcohol use than did high socioeconomic groups. These groups also consumed less fruit, vegetables, fish, and fibre than those of high socioeconomic status. High socioeconomic groups were found to be less physically active and consume more fats, salt, and processed food than individuals of low socioeconomic status. While the included studies presented clear patterns for tobacco use and physical activity, heterogeneity between dietary outcome measures and a paucity of evidence around harmful alcohol use limit the certainty of these findings. Interpretation Despite significant heterogeneity in exposure and outcome measures, clear evidence shows that the burden of behavioural risk factors is affected by socioeconomic position within LLMICs. Governments seeking to meet Sustainable Development Goal (SDG) 3.4—reducing premature Non-Communicable Disease mortality by a third by 2030—should leverage their development budgets to address the poverty-health nexus in these settings. Our findings also have significance for health workers serving these populations and policy makers tasked with preventing and controlling the rise of Non-Communicable Diseases. Funding WHO.
Somnath Chatterji - One of the best experts on this subject based on the ideXlab platform.
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sociodemographic and socioeconomic patterns of chronic Non Communicable Disease among the older adult population in ghana
Global Health Action, 2014Co-Authors: Nadia Minicuci, Somnath Chatterji, Nirmala Naidoo, Richard B Biritwum, George A Mensah, Alfred Yawson, Paul KowalAbstract:Background : In Ghana, the older adult population is projected to increase from 5.3% of the total population in 2015 to 8.9% by 2050. National and local governments will need information about Non-Communicable Diseases (NCDs) in this population in order to allocate health system resources and respond to the health needs of older adults. Design : The 2007/08 Study on global AGEing and adult health (SAGE) Wave 1 in Ghana used face-to-face interviews in a nationally representative sample of persons aged 50-plus years. Individual respondents were asked about their overall health, diagnosis of 10 chronic Non-Communicable conditions, and common health risk factors. A number of anthropometric and health measurements were also taken in all respondents, including height, weight, waist and hip circumferences, and blood pressure (BP). Results : This paper includes 4,724 adults aged 50-plus years. The highest prevalence of self-reported chronic conditions was for hypertension [14.2% (95% CI 12.8–15.6)] and osteoarthritis [13.8%, (95% CI 11.7–15.9)]. The figure for hypertension reached 51.1% (95% CI 48.9–53.4) when based on BP measurement. The prevalence of current smokers was 8.1% (95% CI 7.0–9.2), while 2.0 (95% CI 1.5–2.5) were infrequent/frequent heavy drinkers, 67.9% (95% CI 65.2–70.5) consume insufficient fruits and vegetables, and 25.7% (95% CI 23.1–28.3) had a low level of physical activity. Almost 10% (95% CI 8.3–11.1) of adults were obese and 77.6% (95% CI 76.0–79.2) had a high-risk waist-to-hip ratio (WHR). Risks from tobacco and alcohol consumption continued into older age, while insufficient fruit and vegetable intake, low physical activity and obesity increased with increasing age. The patterns of risk factors varied by income quintile, with higher prevalence of obesity and low physical activity in wealthier respondents, and higher prevalence of insufficient fruit and vegetable intake and smoking in lower-income respondents. The multivariate analysis showed that only urban/rural residence and body mass index (BMI) were common determinates of both self-reported and measured hypertension, while all other determinants have differing patterns. Conclusions : The findings show a high burden of chronic Diseases in the older Ghanaian population, as well as high rates of modifiable health risk factors. The government could consider targeting these health behaviors in conjunction with work to improve enrolment rates in the National Health Insurance Scheme. Keywords : SAGE; Ghana; aging; health behavior; Non-Communicable Disease (Published: 15 April 2014) Citation : Glob Health Action 2014, 7 : 21292 - http://dx.doi.org/10.3402/gha.v7.21292
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socioeconomic inequalities in risk factors for Non Communicable Diseases in low income and middle income countries results from the world health survey
BMC Public Health, 2012Co-Authors: Ahmad Reza Hosseinpoor, Nicole Bergen, Anton E Kunst, Shirley Harper, Regina Guthold, Dag Rekve, Edouard Tursan Despaignet, Nirmala Naidoo, Somnath ChatterjiAbstract:Background Monitoring inequalities in Non Communicable Disease risk factor prevalence can help to inform and target effective interventions. The prevalence of current daily smoking, low fruit and vegetable consumption, physical inactivity, and heavy episodic alcohol drinking were quantified and compared across wealth and education levels in low- and middle-income country groups.
Ramin Heshmat - One of the best experts on this subject based on the ideXlab platform.
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methodology and early findings of the fourth survey of childhood and adolescence surveillance and prevention of adult Non Communicable Disease in iran the caspian iv study
International Journal of Preventive Medicine, 2017Co-Authors: Roya Kelishadi, Gelayol Ardalan, Mostafa Qorbani, Asal Ataiejafari, Maryam Bahreynian, Mahnaz Taslimi, Mohammad Esmaeil Motlagh, Ramin HeshmatAbstract:Background: The fourth survey of the surveillance system named ‘‘Childhood and Adolescence Surveillance and PreventIon of Adult Non-Communicable Disease’’ (CASPIAN–IV study), was conducted among a national representative sample of Iranian students. This paper describes the methods and early findings of this survey. Methods: This nationwide school-based study was conducted in 31 provinces of Iran among 13486 students, 6-18 years (6640 girls, 75.6% from urban areas) and one of their parents. Results: Mean age of students was 12.5 years. Based on WHO growth curves, 12.2% were underweight, 9.7% overweight, and 11.9% were obese. Abdominal obesity was observed in 19.1% of students. The dominant type of cooking oil in urban families was liquid oil and hydrogenated fat (39% and 32%), most rural families used hydrogenated fat (53%), respectively. A total of 18% of students had at least 30 minutes of daily physical activity; 41% of students used computer in weekdays and 44% used it in weekends. 34.5% of students reported to have at least one cigarette smoker and 21.5% reported to have a waterpipe smoker in their relatives. Moreover, 20.3% of students reported that they had suffered an injury needing the help of school health providers during the year prior to the study. Conclusion: Current evidence on the health risky behaviors among Iranian children and adolescents confirms the importance of conducting comprehensive surveillance surveys to identify health risk behaviors. Data of this survey and the trend of variables provide necessary information for health policy makers to implement action-oriented interventions. Key words: Surveillance, chronic Diseases, risk behaviors, risk factors, school health, prevention
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methodology and early findings of the fourth survey of childhood and adolescence surveillance and prevention of adult Non Communicable Disease in iran the caspian iv study
International Journal of Preventive Medicine, 2017Co-Authors: Roya Kelishadi, Gelayol Ardalan, Mostafa Qorbani, Asal Ataiejafari, Maryam Bahreynian, Mahnaz Taslimi, Mohammad Esmaeil Motlagh, Ramin HeshmatAbstract:Background: This paper presents the methodology and early findings of the fifth survey of a school-based surveillance program in Iran. Methods: This nationwide study was conducted in 2015 as the fifth survey of a surveillance program entitled Childhood and Adolescence Surveillance and PreventIon of Adult Non- Communicable Disease (CASPIAN-V) study. The protocol was mainly based on the World Health Organization-Global School student Health Survey. We studied 14400 students, aged 7-18 years, and their parents living in 30 provinces in Iran. Fasting blood was obtained from a sub-sample of 4200 randomly selected students. Results: The participation rate for the whole study and for blood sampling were 99% and 91.5%, respectively. The mean (SD) age of participants was 12.3 (3.2) years, consisting of 49.4% girls and 71.4% urban residents. Overall, 16.1% were underweight (17.4% of boys and 14.8% of girls), and 20.8% had excess weight consisting of 9.4% (8.7% of boys and 10.2% of girls) of overweight and 11.4% (12.5% of boys and 10.3% of girls) of obesity. Abdominal obesity was documented in 21.1% of students (21.6% of boys and 20.5% of girls). Low HDL-C was the most prevalent abnormality of the lipid profile (29.5%) followed by high serum triglycerides (27.7%). Of students, 59.9% consumed whole wheat bread; and 57% reported that they never or rarely added salt to table. The reported daily consumption of fresh fruits, vegetables, and milk was about 60%, 32% and 40%, respectively. 13.7% of participants had at least 30-min daily leisure-time physical activity. Conclusions: The current findings provide an overview of the current health status and lifestyle habits of children and adolescents. This surveillance program would help planning preventive programs at individual and community levels.
Sumeet Sodhi - One of the best experts on this subject based on the ideXlab platform.
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a systematic review of primary care models for Non Communicable Disease interventions in sub saharan africa
BMC Family Practice, 2017Co-Authors: Jennifer Kane, Megan Landes, Christopher Carroll, Amy Nolen, Sumeet SodhiAbstract:Chronic Diseases, primarily cardiovascular Disease, respiratory Disease, diabetes and cancer, are the leading cause of death and disability worldwide. In sub-Saharan Africa (SSA), where Communicable Disease prevalence still outweighs that of Non-Communicable Disease (NCDs), rates of NCDs are rapidly rising and evidence for primary healthcare approaches for these emerging NCDs is needed. A systematic review and evidence synthesis of primary care approaches for chronic Disease in SSA. Quantitative and qualitative primary research studies were included that focused on priority NCDs interventions. The method used was best-fit framework synthesis. Three conceptual models of care for NCDs in low- and middle-income countries were identified and used to develop an a priori framework for the synthesis. The literature search for relevant primary research studies generated 3759 unique citations of which 12 satisfied the inclusion criteria. Eleven studies were quantitative and one used mixed methods. Three higher-level themes of screening, prevention and management of Disease were derived. This synthesis permitted the development of a new evidence-based conceptual model of care for priority NCDs in SSA. For this review there was a near-consensus that passive rather than active case-finding approaches are suitable in resource-poor settings. Modifying risk factors among existing patients through advice on diet and lifestyle was a common element of healthcare approaches. The priorities for Disease management in primary care were identified as: availability of essential diagnostic tools and medications at local primary healthcare clinics and the use of standardized protocols for diagnosis, treatment, monitoring and referral to specialist care.