Comparison of actual (measured) weights and heights with the standard formula methods of estimation among children in Enugu

Abstract

Background: In paediatric practice, weight and height are required for therapeutic and diagnostic interventions. In some circumstances actual anthropometric measurements are not possible and estimates are used. Several formulae are in use for weight and height estimations. The adequacy of these estimates has not been tested for our children. The aim of the current study was to compare the adequacy of formula methods of
weight and height estimation with measured values in children.
Materials and Methods: This was a comparative observational study.
Children who met the inclusion criteria were selected consecutively and studied over a two month period using a semi-structured questionnaire.
Weight and height of each child were measured and recorded to the nearest 0.1kg and 0.1cm respectively using standard protocols. Weight and height for age were also estimated using the universally accepted formulae. Data were analyzed using SPSS 19.0. Paired t- test was used to compare the means of actual and estimated weights and heights according to age. The level of significance was set at p<0.05.
Results: A total of 370 children were studied. They were aged one year two months to 12years. Among children .2 years the measured weights and estimated values showed no significant difference. However, in children
3-5years, the estimated weights were significantly lower than the measured weights. There was no consistent relationship for children 7.12 years where a different formula was used to estimate weight. For heights, the estimated values were significantly lower than the measured except for two year olds
where both where almost similar. Scatter diagrams comparing actual and estimated plots showed linear relationship.
Conclusion: The current methods of estimation are underestimating weights and heights of children in our environment. There is need for a multi-centre cohort study to test the various formulae in our children.

Key words: Measured, Estimated, Weight, Height, Children.