ABSTRACT
BACKGROUND: In this paper we present growth height standards obtained by an auxological study on a primary school population of central Italy (Lazio), in the 1991-1992 and 1992-1993 school-years. METHODS: 4,175 children were included in the study: 2,024 females and 2,151 males, aged from 6 to 11 years. The sampling rate corresponds to more than 98% of the total primary school-population of the areas mentioned. The statistical analysis of the collected data was carried out by the Dipartment of Statistics of the University of Rome, using the widely available statistics packages STAT-GRAPHICS and SAS. RESULTS AND CONCLUSIONS: The analysis of height mean and standard deviation showed an increasing trend of height related to age, without significant differences by sex. The mean heights for females and males were practically the same in each age class. Height variance increases with age, too. This fact necessitates the use of the weighted regression technique to evaluate the functions that express the height growth trend. The relationship between height and age is linearlike and almost coincides for the two sexes. The height percentiles were calculated and the relative curves were developed, based on the distribution of normalized residuals. The centile curves confirm that there are no significant differences in the growth trends for both sexes and therefore the lines are overlapping. Substantial differences exist only in the end centiles (3th and 97th) and age extremes (6 and 11 years), possibly because of the small number of subjects.
