Conclusion

In spite of significant progress in maternal and in­fant care and an associated substantial decline in infant mortality in this century, our research, as well as that of many other contemporary scholars, points to the persistence of a strong inverse associa­tion between economic status and the probability that a newborn infant will survive the first year of life.

This conclusion implicitly assumes that causality runs solely from low income to high infant mortality. But though such an assumption can be justified on the grounds that we are dealing with infants rather than adults, we cannot rule out the possibility that the general inverse relationship reflects two-way causality. That is, the poor health of parents may contribute to lower income, which is such a potent determinant of infant life chances. This possibility does not detract, however, from the validity of the overall conclusion, namely that the infant mortality rate is a powerful indicator of the general health status of a population group.

The fact that infant mortality rates have declined at all income levels obviously indicates that the bene­fits of new and improved infant health care programs do reach all segments of the population eventually. However, the persistence of the strong inverse associa­tion between infant mortality and income status points to the existence of a social class differential in access to health care services and facilities. The first to benefit from advances in medical technology and other health care improvements are those in the high­est income classes, and only gradually do the fruits of such progress filter down to the economically de­prived groups.

Efforts to meet this challenge must, of course, be guided by the knowledge that a wide variety of fac­tors associated with a low economic status contrib­ute to the observed differences in mortality, and that each of these factors will require very different kinds ofprograms to bring them under control. In the past, major efforts focused on those factors that exerted a direct influence on the survival chances of infants, including the adequacy of their diet; the quality of housing, water, and home sanitary facilities; and their immunization status.

These factors, which directly influence exogenous causes (e.g., parasitic diseases and respiratory infec­tions), have already been brought fairly well under control by various public health programs, and what were once the major killers of infants and young chil­dren now account for a very small fraction of the total deaths under 1 year of age. Nevertheless, because the exogenous-disease death rates continue to vary in­versely with economic status, it is clear that the prog­ress made in the prevention and treatment of these diseases has not benefited all groups equally. There is an obvious need to continue and even accelerate ef­forts to extend the full benefits of advances in medical knowledge and health care practices to the more eco­nomically deprived segments of the population.

By far the biggest challenge today, however, con­cerns endogenous conditions, which account for about 80 percent of all infant deaths in the United States. These causes, which have traditionally been re­garded as less amenable to societal control, reflect such things as social class differences in reproductive behavior (age at childbearing, length of interval be­tween pregnancies), differences in the amount and quality of prenatal care (timing of first prenatal ex­amination, frequency of visits), and other maternal characteristics such as adequacy of diet during preg­nancy, amount of weight gain, smoking habits, and the use of drugs or alcohol.

It has recently been recognized that a low birth weight seriously impairs an infant’s chances for sur­vival. A major policy goal, therefore, should be the prevention of low birth weights. Evidence suggests that efforts to do this must go beyond simply provid­ing more and better prenatal care and concentrate on enhancing the overall quality of life and general health status of low-income mothers (Wise et al. 1985). A similar conclusion applies to less developed countries, where it is also recognized that reducing high infant mortality rates will depend more on gen­eral socioeconomic development than on the imple­mentation of conventional health strategies (Gwat- kin 1980). In the meantime, we will continue to live in a world where the level of infant mortality serves as a major barometer of the quality of life in any given environmental setting and the overall health status of the population.

Edward G. Stockwell