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.
David Moore Robert Hogg BC Centre for Excellence in HIV/AIDS Jerry Spiegel Centre for International Health University of British Columbia Vancouver, BC
References
- 1.Global IDEA Scientific Advisory Committee. Health and economic benefits of an accelerated program of research to combat global infectious diseases [editorial]. CMAJ 2004;171(10):1203-8. [DOI] [PMC free article] [PubMed]
- 2.Jha P, Lavery J. Evidence for global health [editorial]. CMAJ 2004;170(11):1687-8. [DOI] [PMC free article] [PubMed]
- 3.Easterlin R. How beneficial is the market? A look at the modern history of mortality. Eur Rev Econ Hist 1999;3:257-94. [DOI] [PubMed]
- 4.McKeown T. The role of medicine: dream, mirage or nemesis. Princeton (NJ): Princeton University Press; 1979.
- 5.Moore D, Castillo E, Richardson C, Reid RJ. Determinants of health status and the influence of primary health care services in Latin America, 1990-98. Int J Health Plann Manage 2003;18: 279-92. [DOI] [PubMed]
- 6.Black JA. The population Doomsday forecast: lessons from Kerala. J R Soc Med 1993;86:704-6. [DOI] [PMC free article] [PubMed]
- 7.Caldwell J. Routes to low mortality in developing countries. In: Caldwell J, Santow G, editors. Selected readings in the cultural, social and behavioural determinants of health. Canberra, Australia: Highland Press; 1989.