[Evolution of child undernutrition in Chile and some of its conditioning factors: a time series analysis].

The objective of this study was to determine the evolution of the nutritional status of the population under five years of age during the period 1975-1990. Several conditioning factors were also assessed. The information was evaluated through time series analysis by using the AREG procedure. This procedure allows for the estimation of a regression model correcting by the autocorrelation of errors. Results indicates a significant trend to decreased undernutrition rates (p < 0.0001). A seasonal effect on undernutrition was observed, being higher the prevalences in summer. Analysis of selected conditioning factors, as well as the familiar buying capacity remained stable during the period. An exception to the lack of association among undernutrition and the conditioning factors evaluated, was seen during the period 1975-1982 when clear inverse relationship was evidenced. In conclusion, the decrease of infant undernutrition in Chile during the period 1975-1990 was not related to the changes observed in certain socioeconomic indices.