Per capita gross national product and summarized odds ratio for epidemiologic studies on the relationship between passive smoking and lung cancer.

: The summarized odds ratios of epidemiologic studies on the relationship between exposure to environmental tobacco smoke (ETS) and lung cancer by country were recalculated, using the odds ratio values in a 1992 report entitled, "Respiratory Health Effects of Passive Smoking: Lung Cancer and Other Disorders" by the US Environmental Protection Agency. The relationship between the summarized odds ratio and per capita gross national product (GNP) in 1964 was studied by the country. The graphic relationship between the summarized odds ratio (ordinate) and GNP (abscissa) showed an upward convex curve. The summarized odds ratios of a developing country (China) and developed countries (USA, Western Europe) in 1964 indicated a very weak association, while those of other countries (Greece, Hong Kong, and Japan) were slightly greater than unity (1.0). This means that ETS in the developing and developed countries in 1964 hardly affected lung cancer, whereas that in the other areas affected lung cancer somewhat. Socioeconomic status in developed countries is far better than that in developing countries, and factors related to socioeconomic status may affect the summarized odds ratio. It is recognized that cancer is diagnosed clinically some years after cancer risk factors appear. If the socioeconomic status involves some risk factors which affect lung cancer, the relationship between the summarized odds ratio and the GNP may be significant. Therefore, we can forecast that the summarized odds ratio of Japan will decrease to close to unity and that that of China will increase in the future because of economic growth, making it possible for the Chinese Government to adopt a policy to reduce the influence of ETS on health.