Harvard University Initiative for Global Health Global Health Challenges Social Analysis 76: Lecture 17

Harvard University Initiative for Global Health Risk Factor Framework Risk Factors for Poor Households in Poor Countries Poor Water Supply, Sanitation and Hygiene Indoor Air Pollution Undernutrition

Harvard University Initiative for Global Health Simplified causal web linking exposures and outcomes

Harvard University Initiative for Global Health Attributable and avoidable burden Attributable burden - current burden due to past exposure Avoidable burden - future burden avoidable if current and future exposure levels are reduced

Harvard University Initiative for Global Health Attributable and avoidable burden

Harvard University Initiative for Global Health For most risk factors, the attributable burden of disease is based on two steps. First, measure relative risks of cause-specific mortality and morbidity as a function of exposure in epidemiological cohort studies. These are assumed in most cases to be generalizable across populations. Second, measure local levels of exposure to the risk by age and sex. Relative Risk and Exposure

Harvard University Initiative for Global Health Body mass indexBlood pressure Cholesterol Systolic blood pressure (mmHg)Body mass index (kg/m 2 ) Risk of coronary disease Continuous exposure and disease associations Hyper- tension Hyperchol- esterolaemia Obesity Total cholesterol (mmol/l)

Harvard University Initiative for Global Health Systematic assessment of all available sources of exposure data including household surveys, consumption data, community studies and others. For some risks in some epidemiological regions figures are based on covariates e.g. indoor air pollution based on GDP, fossil fuel imports and other socio- demographic variables. Exposure Data

Harvard University Initiative for Global Health Risk Factor Framework Risk Factors for Poor Households in Poor Countries Poor Water Supply, Sanitation and Hygiene Indoor Air Pollution Undernutrition

Harvard University Initiative for Global Health Attributable Disease Burden of 20 Risk Factors

Harvard University Initiative for Global Health Risk Factor Framework Risk Factors for Poor Households in Poor Countries Poor Water Supply, Sanitation and Hygiene Indoor Air Pollution Undernutrition

Harvard University Initiative for Global Health Unsafe Water and Sanitation

Harvard University Initiative for Global Health

Major public health emphasis in the 1980s. Early 1990s, recognition that as a health intervention, it is relatively more costly than other health technologies. As a development intervention it may still be a priority intervention. Classic example highlighting the difficulty of analyzing interventions with benefits in different sectors. Little progress has been made in the last decade above and beyond that expected for economic growth. Renewed interest with Johannesburg Environment Conference. Improved Water Supply

Harvard University Initiative for Global Health Meta-Analysis of the Reduction in Diarrhoea Morbidity – Fewtrell et al. 2005

Harvard University Initiative for Global Health

Risk Factor Framework Risk Factors for Poor Households in Poor Countries Poor Water Supply, Sanitation and Hygiene Indoor Air Pollution Undernutrition

Harvard University Initiative for Global Health

1)Behavioural change to reduce exposure e.g. keep young babies away from cooking fire. 2)Changes in household ventilation: windows in kitchens, gaps between roof and wall, move stove out of living area. 3)Improved stove technology – more efficient combustion to reduce toxic pollutants. 4)Shift to higher quality low emission fuels such as kerosene, LPG, biomass based alcohol. Interventions

Harvard University Initiative for Global Health China has undertaken a major effort to switch poor rural households to more efficient stoves. A number of local projects have been successful in changing ventilation and stove design. Easiest policies to implement are switching to clean fuels but poor households can only switch if these fuels are subsidized. For very poor communities, this is unlikely to happen. For poor households in middle-income countries, this strategy can work. Little policy effort globally on indoor air pollution as health hazard. Inclusion of solid fuel use for cooking as a Millennium Development Goal Indicator may stimulate more attention. Indoor Air Pollution Policy Efforts

Harvard University Initiative for Global Health Risk Factor Framework Risk Factors for Poor Households in Poor Countries Poor Water Supply, Sanitation and Hygiene Indoor Air Pollution Undernutrition

Harvard University Initiative for Global Health

Source: Demographic and Health Surveys

Harvard University Initiative for Global Health Undernutrition very highly correlated with poverty. Interventions that raise the purchasing power of the poor will decrease undernutrition. Famine relief e.g. in India has been highly effective at attenuating acute malnutrition. Interventions to reduce undernutrition without changing household income status such as supplementary feeding programs can work but without very large impacts. Lower cost strategies targeting micronutrient deficiencies have been more effective. Interventions

Harvard University Initiative for Global Health Acute undernutrition during periods of famine is also a major factor. Although the burden from chronic undernutrition is much larger than from famine at the global scale. Drought compounded with decreased social coping capacity because of the HIV epidemic in Southern Africa put the region at high risk in 2002/3. New variant famine hypothesis: disease like HIV is the underlying cause of loss of economic power and decreased access to food in at risk populations. Famine