0～7岁儿童生长曲线的制定及其应用

目的：制订一套0-7岁儿童的百分位生长曲线图供儿童保健及临床工作使用。方法：根据1995年第三次中国九城市城郊7岁以下儿童体格发育横断面调查所获得的数据，采用9个市城区0-7岁79154名健康男女儿童（其中0-3岁儿童53954名）的年龄别身高（3岁以下为身长）、年龄别头围的平均值、标准差以及年龄别体重和身高别体重的百分位数，先用多项式方程将他们修匀，然后修匀后的值计算各百分位并绘制曲线图。结果：为0-3岁男女儿童制定了各自的年龄别体重、年龄别身高和身高别体重的3、10、25、50、75、90及97百分位曲线图。结论：使用简便、直观的生长标准曲线图有利于个体儿童的生长监测，早期识别生长偏离的现象，为促进儿童生长和健康服务。

Growth curves of children from birth to 7 years of age

Objective To construct a set of percentile growth curves for children from birth to 7 years of age for both clinical and preventive health care uses. Methods The third national growth survey of children below 7 years of age in the nine cities of China was performed in 1995 and from this survey, data of the 79 154 urban healthy children (53 954 of them were below 3 years of age) were used to construct the weight for age, height for age (height was measured supine for children below 3 years), head circumference for age and weight for height percentile curves. Smoothing was performed separately for each sex, below and after 3 years of age. The means, standard deviations of the height for age and head circumference for age, the percentiles of weight for age and weight for height were used to construct the smoothed curves by polynomial equations. The smoothing methods were as follows: height and head circumference were confirmed to be normally distributed variables, so that the means and SDs at each age were smoothed with polynomial equations.The smoothed SDs were multiplied by K value and then were added to the smoothed means to calculate the 3rd, 10th, 25th, 50th, 75th, 90th and 97th percentiles: that were, -1.881, -1.282, -0.675, 0, +0.675, +1.282, +1.881, respectively. Because weight was non-normally distributed variable, the 3rd, 10th, 25th, 50th, 75th, 90th and 97th percentile values of weight at each age were determined. The median curve was smoothed with polynomial equations, with goodness of fit, R 2=0.999. Distance between observed percentiles and the smoothed median curve at all age points were smoothed. Then various percentile lines were smoothed again by polynomial equations. Smooth percentile curves were then constructed. For weight-for height, the percentile values for each 1 cm length/height interval were determined and then smoothed by polynomial equations. Results The 3rd,10th, 25th, 50th, 75th, 90th, 97th percentile curves of weight-for-age, length-for-age and head circumference-for-age for boys and girls aged 0-3 years and the 3rd,10th, 25th, 50th, 75th, 90th, 97th percentile curves of weight-for-age, height-for-age and weight-for-height for boys and girls aged 0-7 years were made out respectively. Conclusion The percentile growth curves are very useful in the sequential monitoring of individual health, discovering growth divergence and service for promoting child growth and health.