Omisanjo A O, Orimadegun A E, Akinbami F O
Department of Paediatrics, University College Hospital, Ibadan, Nigeria.
Institute of Child Health, College of Medicine, University of Ibadan, Ibadan, Nigeria.
Ann Ib Postgrad Med. 2014 Dec;12(2):80-8.
An alternative method of estimating children's weights, when direct weighing is impracticable is the use of age-based formulae but these formulae have not been validated in Nigeria. This study compares estimated weights from two commonly used formulae against actual weights of healthy children.
Children aged 1 month to 11 years (n= 2754) were randomly selected in Ibadan, Nigeria using a two-stage sampling procedure. Weight of each child, measured using a standard calibrated scale and determined using Nelson and Best Guess formulae, were compared. Demographic characteristics were also obtained. Mean percentage error (MPE) was calculated and stratified by gender and age. Bland-Altman graphs were used for visual assessment of the agreement between estimated and measured weights. Clinically acceptable MPE was defined as ±5%. Descriptive statistics and paired t test were used to examine the data. Statistical level of significance was set at p = 0.05.
There were 1349 males and 1405 females. Nelson and Best Guess formulae overestimated weight by 10.11% (95% CI: -20.44, 40.65) in infants. For 1-5 years group, Nelson formula marginally underestimated weight by -0.59% (95% CI: -5.16, 3.96) while it overestimated weight by 9.87% (95% CI: 24.89, 44.63) in 6-11 years. Best Guess formulae consistently overestimated weight in all age groups with the MPE ranging from 10.11 to 30.67%.
Nelson and Best Guess formulae are inaccurate for weight estimations in infants and children aged 6-11 years. Development of new formulae or modifications should be considered for use in the Nigerian children population.
当直接称重不可行时，一种估计儿童体重的替代方法是使用基于年龄的公式，但这些公式在尼日利亚尚未得到验证。本研究比较了两种常用公式估计的体重与健康儿童的实际体重。
采用两阶段抽样程序，在尼日利亚伊巴丹随机选取1个月至11岁的儿童（n = 2754）。比较了每个儿童使用标准校准秤测量的体重以及使用纳尔逊公式和最佳猜测公式确定的体重。还获取了人口统计学特征。计算平均百分比误差（MPE），并按性别和年龄分层。使用布兰德-奥特曼图直观评估估计体重与测量体重之间的一致性。临床上可接受的MPE定义为±5%。使用描述性统计和配对t检验来检验数据。统计学显著性水平设定为p = 0.05。
有1349名男性和1405名女性。纳尔逊公式和最佳猜测公式在婴儿中高估体重10.11%（95%CI：-20.44，40.65）。在1 - 5岁组中，纳尔逊公式略微低估体重-0.59%（95%CI：-5.16，3.96），而在6 - 11岁组中高估体重9.87%（95%CI：24.89，44.63）。最佳猜测公式在所有年龄组中均持续高估体重，MPE范围为10.11%至30.67%。
纳尔逊公式和最佳猜测公式在婴儿和6 - 11岁儿童的体重估计中不准确。应考虑开发新的公式或进行修改以用于尼日利亚儿童群体。
