Weight estimation in Paediatrics: How accurate is the Broselow-tape weight estimation in the Nigerian child

Abstract

Background: Determination of weight in children is an important aspect of their assessment. It has a wide range of usefulness including assessing their nutritional status and drug dose calculation. Despite its usefulness, weight estimation in children in certain conditions can be challenging particularly in emergency situations or in children who are severely ill or cannot stand on standard scales. The Broselow Tape which is a validated tape that is used to estimate weight based on length was developed using height/weight correlations from Western data. However, considering the variations in anthropometric measurements of children from different geographic locations, there is need to ascertain how accurate it is to estimate weight using the Broselow tape among children in Nigeria. Aim: The study was carried out to determine the accuracy in the use of the Broselow Tape in weight estimation among Nigerian children. Method: A total 1456 children aged 1-12 years who satisfied the inclusion criteria were enrolled over a 2½ year period from two tertiary health facilities in Enugu state Nigeria. Weight was taken using standard weighing scale and Broselow tape. Data collected was analysed using SPSS. Result: Of the 1456 children studied, majority (84.2%) had normal Body-Mass-Index (BMI) while about 4.6% had a low BMI percentile for age. The mean weight difference between the two methods was not significantly different between the 1 to 6 years old category. Significant differences were observed from 7 up to 12 years. The Broselow Tape overestimated weights in 1 year old by 3.88%, 2 years 1.58%, 3 years by 2.13%, 4 years (1.94%) and 5 year (0.07%). After 5 years, the degree of overestimation rises sharply to 4.25% in 6, 9.25% in 7, 7.29% in 8 and 9.29%. 9.18, 11.61% & 6.75% in 9, 10, 11 and 12 years old respectively. The proportion of estimated weights that was within 10-20% of the actual weight was higher in the 1-6 years age categories compared to weight estimates in older age categories. Conclusion: Weight estimates obtained using the Broselow tape correlated better in children that are 6 years or younger compared to those in the older age categories. There is need for re-validation and/or adjustments of the Broselow tape especially in children over 6 years old.