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A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions


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A systematic analysis for the Global Burden of Disease Study 2010

Stephen Lim, on behalf of the GBD 2010 Comparative Risk Assessment Group

The Royal Society, 14 December 2012

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A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions

  1. 1. A comparative risk assessment of burden ofdisease and injury attributable to 67 riskfactors and risk factor clusters in 21 regionsA systematic analysis for the Global Burden of Disease Study 2010Stephen Lim, on behalf of the GBD 2010Comparative Risk Assessment GroupThe Royal Society, 14 December 2012
  2. 2. Comparative Risk Assessment 20101. Reliable and comparable analysis of risks to health is a key input for informing disease and injury prevention.2. Previous topic-specific analyses, e.g., maternal and child undernutrition, physical inactivity, use different methods and data3. No complete and comparable analysis across a large set of risk factors since the CRA 2000. 2
  3. 3. Methods1. Calculate the proportion of deaths or disease burden holding other independent factors unchanged.2. Counterfactual analysis: What if risk exposure was at a different level?3. 67 risk factors and clusters of risk factors.4. 20 age groups, both sexes, 187 countries, and for 1990, 2005, and 2010. 3
  4. 4. GBD 2010 – risks quantifiedUnimproved water and sanitation Tobacco smoking and secondhand smokeUnimproved water Tobacco smokingUnimproved sanitation Second-hand smokeAir pollution Alcohol and other drugsAmbient particulate matter pollution Alcohol useHousehold air pollution from solid fuels Drug use (opioids, cannabis, amphetamines)Ambient ozone pollution Physiological risks for chronic diseasesOther environmental risks High fasting plasma glucoseResidential radon High total cholesterolLead exposure High systolic blood pressureChild and maternal undernutrition High body mass indexSuboptimal breastfeeding Low bone mineral density Non-exclusive breastfeeding Sexual abuse and violence Discontinued breastfeeding Childhood sexual abuseChildhood underweight Intimate partner violenceIron deficiencyVitamin A deficiencyZinc deficiency 4
  5. 5. GBD 2010 – risks quantified (2)Dietary risk factors and physical inactivity Occupational exposuresDiet low in fruits Occupational exposure to asbestosDiet low in vegetables Occupational exposure to arsenicDiet low in whole grains Occupational exposure to benzeneDiet low in nuts/seeds Occupational exposure to berylliumDiet low in milk Occupational exposure to cadmiumDiet high in unprocessed red meat Occupational exposure to chromiumDiet high in processed meat Occupational exposure to dieselSugar-sweetened beverages Occupational exposure to formaldehydeDiet low in fibre Occupational exposure to nickelDiet low in calcium Occupational exposure to PAHsDiet low in seafood omega-3 Occupational exposure to secondhand smokeDiet low in polyunsaturated fatty acid (PUFA) Occupational exposure to silicaDiet high in trans fatty acids Occupational exposure to sulfuric acidDiet high in sodium Occupational exposure to asthmagensPhysical inactivity and low physical activity Occupational exposure to particulates and gases Occupational noise Occupational risk factors for injury Occupational low back pain 5
  6. 6. Calculating risk factor burden1. Select risk-outcome pairs;2. Estimate exposure distributions to each risk factor in the population;3. Estimate cause effect sizes: relative risk per unit of exposure for each risk-outcome pair;4. Choose a counterfactual exposure distribution: theoretical minimum risk exposure distribution (TMRED); and5. Compute attributable burden, including uncertainty. 6
  7. 7. Risk-outcome inclusion criteria1. Likely importance of a risk factor to disease burden or policy;2. Availability of sufficient data and methods to enable estimation of exposure distributions by country for at least one of the study periods;3. Sufficient evidence for causal effect (convincing or probable evidence) and to estimate outcome-specific effect sizes; and4. Evidence to support generalizability of effect sizes to populations other than those included in epidemiological studies. 7
  8. 8. Exposure: ambient PM pollution 8
  9. 9. Exposure: ambient PM pollution (2) • Satellite-based measures of aerosol optical depth (AOD) • TM5 chemical transport models • Calibrated against ground-based PM2.5 sensorsPM2.5 (µg per m3) 9
  10. 10. Risk-outcome effect sizes1. Recent or new systematic reviews and meta-analyses2. New effect size estimates conducted for: • Water and sanitation • Air pollution: integrated exposure response (IERs) • Dietary risk factors3. Examined validity of single dietary risk factor effect sizes: • Dietary pattern studies, e.g. Mediterranean diet • Randomized controlled feeding studies, e.g. DASH, OMNI Heart 10
  11. 11. DALYs 2010attributableto diet andphysicalinactivity 11
  12. 12. Burden of disease attributable to 20 leading risk factors in 2010, expressedas a percentage of global disability-adjusted life years, both sexes 12
  13. 13. 95% uncertainty intervals for risk factors, 2010 13
  14. 14. Comparing deaths and DALYs in 2010 14
  15. 15. Global risk factor ranks with 95% UI for all ages and sexescombined in 1990 and 2010, and percentage change 15
  16. 16. Regional variation in leading risks, 2010 16
  17. 17. Attributable burden for each risk factor as apercentage of disability-adjusted life years in 2010 17
  18. 18. Additional key findingsImportant revisions compared to previous assessments: • Unsafe water and sanitation • Vitamin A and zinc deficiency • Household and ambient PM pollution • Physical inactivity and low physical activity 18
  19. 19. Limitations• Limited exposure distribution data.• Potential for residual confounding, especially in the absence of intervention studies.• Uncertainty about generalizability of effect sizes across populations.• Exclusion of risk-outcomes based on insufficient data.• Few risks for major communicable diseases.• No adjustment for interactions between risk factors for calculating joint effects. 19
  20. 20. Summary• Dramatic shift away from communicable disease risks in children toward noncommunicable disease risks in adults.• Global rise in high BMI and glucose emphasizes research priorities given the absence of effective interventions.• More nuanced understanding of the role of diet in preventing chronic disease.• Major revisions in the quantification of attributable burden of micronutrient deficiencies and household and ambient air pollution, among others.• In much of sub-Saharan Africa, the leading risks continue to be those associated with poverty. 20