Global IDEA

Recent CMAJ commentaries1^,2 have promoted the view that improved medical technologies are the most promising means of improving population health in developing countries. Although we support an increase in research into global health issues, we feel that clinical research into novel technical solutions will have less success in achieving improvements in population health than these commentaries suggest, for 3 reasons.

First, history shows that improvements in population health status in Western Europe have come largely in the absence of disease-specific control measures. The technologic improvements that coincided with large increases in life expectancy in the late 19th century related to improved sanitation, expanding access to safe water supplies and improvements in living conditions, not to specific medical interventions.3 Similarly, 90% of the reduction in mortality from tuberculosis in England and Wales predated the introduction of BCG (bacille Calmette–Guérin) vaccination or streptomycin.4

Second, in developing countries where significant improvements in population health have occurred in recent decades, other, so-called “upstream” determinants of health (such as female literacy5^,6) appear to be more highly correlated with these changes. Developing countries that have achieved high levels of life expectancy and low levels of mortality, such as China, Sri Lanka and Cuba, have done so primarily because of investments in the social determinants of health (universal education, food subsidies) and a commitment to egalitarian principles.7

Third, the effectiveness of any clinical intervention in the community is always much less than that determined through clinical research, because of problems in health service access, diagnostic accuracy, and transport and management of supplies, among others. The oft-repeated example of vaccination is one of the few exceptions, likely because the intervention is relatively simple, needs to be applied only once or a few times, and does not need to target only those who are already ill.

Operational research is needed to assist developing countries in creating public policies that allow for the expansion of approaches already shown to have a greater impact than medical technology: access to safe drinking water, effective sanitation, safe housing, adequate nutrition (especially for women and children) and universal education. Furthermore, local health service research in low-income countries would greatly assist these countries to expand application of their current arsenal of effective health care interventions. Yes, developing countries have been neglected in terms of biomedical and clinical research into infectious diseases, but the technical knowledge needed to improved population health in developing countries already exists.