Public Health Challenge

We know that disparities in life expectancy, disability-adjusted life years, overall mortality and cancer mortality can develop as a result of regional variation, unique environmental, or differential socioeconomic circumstances. Factors such as economic development, diet, tobacco, alcohol consumption, health care expenditures and education levels, play a significant role in the incidence of cancer in industrialized nations and generally economic development is great news for health. But is improvement in a country's health as simple as fostering economic development, especially for countries in the developing world? Armed with a framework of the components of economic development integrated with traditional public influencers, Dr. Harvey Brenner and his colleague and economist, Lawrence Klein, set out to learn more.

Research Findings

With countries as the unit of analysis, prediction of several health outcomes was fairly successful with a lean set of readily available indicators. Adjusted R squared for multiple regressions on life expectancy, health adjusted life expectancy, and age-standardized DALYs ranged between 0.87-0.95. The variables common to all three outcomes were: gross domestic product, per capita alcohol consumption, CO2 emissions, government health expenditure as percent of total government expenditure, birth rate, availability of improved sanitation in urban areas, school success, and HIV prevalence; tobacco consumption was important for life expectancy at birth only. The percentage of the variation predicted for countries’ cancer mortality was somewhat less at 0.74. The important protective country factors were per capita GDP, percentage of the economy in the agriculture sector, percentage of the GDP in the service jobs sector, percentage of the working population who are self-employed, per capita education expenditures and school enrollment. Country-level factors impeding health included: percentage of animal fat calories of total consumption, alcohol consumption per capita, per capita cigarette consumption, boy to girl educated ratio, and total health expenditure as percent of GDP. These factors ranged in statistical significance according to the cancer site. Prediction of individual cancer sites ranged between 0.54 and 0.76 (adjusted R squared) with bladder, lung and ovary among the best models. Six of the eight sites (bladder, breast, cervix, colon, lung, ovary, pancreas, and prostate) examined were predicted by percentage of self-employed individuals and five out of eight, were predicted by per capita GDP, percentage of animal fat of all food consumed, total health expenditure as percent of GDP, and primary school enrollment.

Possible Directions

More detail is needed to assess the effects in developed compared to developing countries and to verify the proposed frameworks. Also worth exploring is the fact that unemployment rate for men and women uniquely predicts bladder cancer; perhaps there is an associated exposure. The fact that animal fat and not vegetable fat is associated with poor cancer outcomes is one that may direct individual level studies to once again delve into the components of diet that make a difference in health.

Future Research Opportunities

Various economic factors influence the industrialized and industrializing countries of the world where mortality is the concern. Economic development can produce increases or decreases in cancer mortality. Healthful factors for countries differ from those factors important for personal health. For example, tobacco consumption did not always detract from the health of a country. Dr Brenner and colleagues have a global network of investigators interested in fleshing out answers to development’s effect on population health around the world.