Impact of economic development, fertility trends, and national immunization and ORT efforts on infant/child survival, Dominican Republic and Thailand, 1950-1982

This paper reports a successful test of an integrated theoretical model - based on historical developments in the economy, public investment, technological change, and fertility - to account for changes in infant/child mortality rates in the Dominican Republic and Thailand between 1950-1982. The model was tested on infant/child mortality rates derived from: vital registration; UN and World Fertility Survey 5-year mortality trend-adjusted annual rates; and World Fertility Survey retrospective fertility analysis of annual mortality rates. The analysis of child survival trends in the two countries revealed that the theoretical structures, data bases, and statistical technology were adequate for development of the models. Empirical tests showed the explanatory regression models to be of comparatively high quality by the usual tests performed in time series analysis, and results showed comparability of first difference models with those using untransformed data. The principal empirical findings are as follows. (1) Economic change is the major beneficial factor in the decline and fluctuation in infant/child mortality rates. These economic changes include the trend and fluctuation in real GDP per capita, exports, and indices of food production. (2) Previous years" public investment in health services, education, and sanitation are major factors in the decline in infant and 1-4 year mortality rates. (3) Risk declines related to economic growth include declines in the birth rate, which have contributed significantly to infant/child mortality rate reduction. (4) Risk increases related to economic growth include structural change associated with imported technology; this factor has made significant contributions to increased mortality rates. (5) Immunizations, including DPT and tetanus toxoid given at pregnancy, are significantly related to mortality rate reductions. (6) In Thailand, government estimates of ORT use and coverage were tested and significant reductions in mortality could be measured. In addition, short-term increases in rice production (within 0-2 years) were related to short-term declines in child mortality rates. (7) In the Dominican Republic, increased DPT immunization is related to decline in the infant mortality rate. Also, short-term increases in overall agricultural production (rather than for a specific crop), and overall food consumption are related to 1-4 mortality decreases. We conclude that these integrated national economic and health care models offer, for the first time, the possibility of estimating the simultaneous impact on child survival of national economic changes; prior government expenditures on health, education, welfare, and sanitation; trends in the birth rate; structural changes based on technology importation; and selective health interventions, most importantly immunization and ORT. It is now feasible to compare the cost-effectiveness of a variety of health sector initiatives in terms of the relative strength of their impact on child survival, given differing economic development scenarios. (Author abstract)