Evidence-based priority setting for dietary policies Ashkan Afshin, MD MPH MSc ScD November 17, 2016 Acting Assistant Professor of Global Health
Policy 1. Defining optimal nutrition Agenda Setting Formulation 2. Quantifying the burden of disease due to malnutrition 3 . Evaluating the effectiveness of policies to improve nutrition 4. Evaluating the cost-effectiveness of nutrition policies Policy Policy Evaluation Adoption 5. Evaluating the political/legal feasibility of nutrition policies 6. Evaluating the intensity of implementation of nutrition policies Policy 7. Evaluating the short/long term effects of nutrition policies Implementation
Policy 1. Defining optimal nutrition Agenda Setting Formulation 2. Quantifying the burden of disease due to malnutrition 3 . Evaluating the effectiveness of policies to improve nutrition 4. Evaluating the cost-effectiveness of nutrition policies Policy Policy Evaluation Adoption 5. Evaluating the political/legal feasibility of nutrition policies 6. Evaluating the intensity of implementation of nutrition policies Policy 7. Evaluating the short/long term effects of nutrition policies Implementation
Malnutrition 4
5
1943 2005 1992 2011 2002 2015 1989
Absolute Intake Defining diet Nutrients Foods Dietary patterns Biological mechanism No biological knowledge Intercorrelations not a problem Statistical Power No food composition data needed Between-food interactions Supplementation Use in dietary advice Relative Intake Health outcome Disease endpoints (CVD, diabetes, cancer) Intermediate outcomes (obesity, blood pressure) 7
Evidence Description RCTs of disease endpoint Number of independent RCTs evaluating the effect of the risk on the disease endpoint % of independent RCTs showing significant effect in the opposite direction % of independent RCTs showing no effect Prospective observational studies of Number of independent prospective observational studies evaluating the association of the disease endpoint risk with the disease endpoint % of independent prospective observational studies with significant association in the opposite direction Strength Lower Limit of RR in observational studies> 1.5 (Yes/No) Dose response Evidence of the dose-response relationship between the risk and the outcome(Yes/No) Potential biologic mechanism that could explain the effect of the risk on the disease endpoint Biologic plausibility (Yes/No) Evidence on the relationship between the risk factor and a disease endpoint from the same Analogy category (Yes/No) 8
Epidemiologic evidence supporting causality between dietary risk-outcome pairs RCTs with significant effect in Dose-response relationship RCTs with null findings (%) Prospective observational Prospective observational the opposite direction (%) studies with significant Lower limit of RR > 1.5 Biologic plausibility studies (Number) RCTs (Number) Analogy Risk Outcome Diet low in fruits Lip and oral cavity cancer 0 - - 2 0 Diet low in fruits Nasopharynx cancer 0 - - 2 0 Diet low in fruits Other pharynx cancer 0 - - 2 0 Diet low in fruits Larynx cancer 0 - - 2 0 Diet low in fruits Oesophageal cancer 0 - - 5 0 Diet low in fruits Tracheal, bronchus, and lung cancer 0 - - 22 0 Diet low in fruits Ischaemic heart disease 0 - - 9 0 Diet low in fruits Ischaemic stroke 0 - - 9 0 Diet low in fruits Hemorrhagic stroke 0 - - 5 0 Diet low in fruits Diabetes mellitus 0 - - 9 0 Diet low in vegetables Oesophageal cancer 0 - - 5 0 Diet low in vegetables Ischaemic heart disease 0 - - 9 0 Diet low in vegetables Ischaemic stroke 0 - - 8 0 Diet low in vegetables Hemorrhagic stroke 0 - - 5 0 Diet low in whole grains Ischaemic heart disease 0 - - 7 0 Diet low in whole grains Ischemic stroke 0 - - 6 0 Diet low in whole grains Hemorrhagic stroke 0 - - 6 0 Diet low in whole grains Diabetes mellitus 0 - - 10 0 Diet low in nuts and seeds Ischaemic heart disease 1 0 100 6 0 Diet low in nuts and seeds Diabetes mellitus 1 0 100 5 0 GBD 2015
Epidemiologic evidence supporting causality between dietary risk-outcome pairs RCTs with significant effect in Dose-response relationship Prospective observational Prospective observational RCTs with null findings (%) the opposite direction (%) studies with significant Lower limit of RR > 1.5 Biologic plausibility studies (Number) RCTs (Number) Analogy Risk Outcome Diet low in milk Colon and rectum cancer cancer 0 - - 7 0 Diet high in red meats Colon and rectum cancer cancer 0 - - 8 0 Diet high in red meats Diabetes mellitus 0 - - 9 11 Diet high in processed meats Colon and rectum cancer cancer 0 - - 9 11 Diet high in processed meats Ischaemic heart disease 0 - - 5 0 Diet high in processed meats Diabetes mellitus 0 - - 8 0 Diet high in sugar sweetened beverages Body mass index 10 0 60 22 0 - - Diet low in fibre Colon and rectum cancer cancer 0 - - 15 0 Diet low in fibre Ischaemic heart disease 0 - - 12 0 Diet low in calcium Colon and rectum cancer cancer 0 - - 13 0 Diet low in seafood omega-3 fatty acids Ischaemic heart disease 17 0 94 16 0 Diet low in polyunsaturated fatty acids Ischaemic heart disease 8 0 75 11 0 Diet high in trans fatty acids Ischaemic heart disease 0 - - 4 0 Diet high in sodium Systolic blood pressure 45 0 73 - - - - Diet high in sodium Stomach cancer 0 - - 3 0 GBD 2015
Policy 1. Defining optimal nutrition Agenda Setting Formulation 2. Quantifying the burden of disease due to malnutrition 3 . Evaluating the effectiveness of policies to improve nutrition 4. Evaluating the cost-effectiveness of nutrition policies Policy Policy Evaluation Adoption 5. Evaluating the political/legal feasibility of nutrition policies 6. Evaluating the intensity of implementation of nutrition policies Policy 7. Evaluating the short/long term effects of nutrition policies Implementation
Comparative Risk Assessment 12
Global Nutrient Database Calcium Other nutrients Sugars (Glucose, Sucrose, Starch) Protein Vitamins (A, B, D, E, K) Folates Iron Zinc Magnesium Phosphorus Potassium Selenium GBD 2015
Standardizing the modelling approach Representativeness Suboptimal metric Data from FFQ Data from HBS Data from FAO Nationally Sex Country level covariate Diet low in fruits - Diet low in vegetables - Diet low in whole grains - - Diet low in nuts and seeds - Diet low in milk - Diet high in red meat - Diet high in processed meat - National availability of red meat and pig meat Diet high in sugar-sweetened beverages - National availability of sugar Diet low in fiber - Diet suboptimal in calcium - Diet low in seafood omega-3 fatty acids Landlocked nation (Yes,/No) Diet low in polyunsaturated fatty acids - Diet high in trans fatty acids - National availability of hydrogenated oil Diet high in sodium - - - - GBD 2015 14
Comparative Risk Assessment 15
Age curve of relative risks Total Serum Fasting Plasma Systolic Blood Body Mass Index Cholesterol Glucose Pressure Diet low in fruits Diet low in vegetables - Diet low in whole grains Diet low in nuts and seeds - - Diet high in red meats - Diet high in processed meats - - - Diet low in fiber - - Diet low in seafood omega-3 fatty acids - - Diet low in polyunsaturated fatty acids - - Diet high in trans fatty acids GBD 2015 16
Measurement Error Subar (2001) 17
Publication Bias SSBs & Diabetes Nuts & IHD Trans fat & IHD Processed meat & Diabetes Red meat & Diabetes 18
Definition of dietary factors Wang Huang Johnsen Wu Jacobs Jensen Steffen Liu added bran added wheat germ bagels bran breakfast cereals brown rice brown rice flour buckwheat bulgur cooked cereal cooked oatmeal corn meal dumplings corn meal flat cakes corn meal porridge corn meal steamed bread non-white bread oats other grains pancakes pizza popcorn Aune (2016) psyllium 19
Covariates Hypercholesterolemia Vitamin Supplements Fruit and Vegetables Oral Contraceptives Menopausal Status Physical Excerise Sleep Duration Merital Status Mental Stress Fish/ Seafood Hypertension Red Meat Education Trans- FA Waist/hip Smoking Diabetes Sucrose Sodium Alcohol Engery MUFA Coffee Dairy PUFA Race BMI HRT Age SFA Sex Soy Atkins (2014) Eshak(2011) Eshak (2014) Jacobs(2001) Jensen(2004) Johnsen (2015) Liu (1999) Mink (2007) Muraki (2014) Muraki (2014) Pietinen (1996) Rautiainen (2012) Steffen(2003) Tognon (2014) Wang(2016) Yu (2013) Whole grains and Ischemic Heart Disease Aune (2016) 20
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