Comparison of paediatric weight estimation methods at a tertiary hospital in Ghana

Weight estimation in two groups of Ghanaian children with chronic diseases using Broselow, Mercy, PAWPER XL and PAWPER XL-MAC tapes

Introduction

The performance of various weight estimation methods in children with sickle cell disease (SCD) and heart disease (HD) has not been studied. We aimed to determine and compare the accuracies of the Broselow, Mercy, PAWPER XL and PAWPER XL-MAC tapes in Ghanaian children with no known chronic diseases (controls), SCD and HD.

Methods

We prospectively recruited 631 children (199 with HD, 209 SCD and 223 controls) from the Komfo Anokye Teaching Hospital (KATH). Their weights were estimated using the Broselow, Mercy, PAWPER XL and PAWPER XL-MAC tapes. These estimated weights were compared to measured weight using mean percentage error (MPE), the proportion of weight estimates within ±10% (P10) and ±20% (P20) of measured weight. Bland-Altman limits of agreement (LOA) were determined to assess the precision of weight estimation and agreement with measured weight.

Results

The PAWPER XL, Mercy and PAWPER XL-MAC were the most accurate in all groups of children studied. All methods except the Broselow tape (BT), which performed best in the control group, had their best performance among children with SCD with negligible critical error rates (proportion of children with weight estimates > 20% of their actual weight). The P20 in the various groups of children using the BT were 88.36%, 80.21% and 51.10% respectively in the control, SCD and HD groups. The Mercy, PAWPER XL and PAWPER XL MAC tapes were generally above 90% in all groups.

Discussion

The Mercy, PAWPER XL and PAWPER XL-MAC tapes performed significantly better than the BT in all groups of children studied. These methods of weight estimation performed best in children with SCD with very little critical error.

Accuracy of Weight Estimation in Children Using the Broselow, PAWPER XL, PAWPER XL-MAC, and Mercy Tapes

OBJECTIVES

Quick and accurate estimate of a child's weight is often required for medical interventions like drug dose calculation when scale measured weights cannot be obtained safely. Length-based methods of weight estimation are more accurate than age-based methods, with the most accurate being the length-based, habitus-modified methods. This study sought to determine and compare the accuracies of the 2017 Broselow tape, Paediatric Advanced Weight Prediction in the Emergency Room Extra-Long (PAWPER XL) tape, Paediatric Advanced Weight Prediction in the Emergency Room Extra-Long Mid-Arm Circumference (PAWPER XL-MAC) tape, and the 2-dimensional (2D) Mercy tape in Ghanaian children.

METHODS

A cross-sectional study was conducted at the Tamale Teaching Hospital in Ghana. Eight hundred forty children between 2 months and 13 years had their weights estimated by the 2017 Broselow, PAWPER XL, PAWPER XL-MAC, and 2D Mercy tapes. Accuracy of the methods was determined by percentage of weight estimated to within 10% and 20% of actual weight. Mean percentage error and the Bland-Altman analysis were used to assess bias and precision.

RESULTS

The proportion of weight estimates within 10% and 20% of actual weight for Broselow tape were 47.5% and 82.3%, for 2D Mercy tape were 73.1% and 96.3%, for PAWPER XL-MAC were 77.6% and 97.5%, and for PAWPER XL were 81.7% and 96.8%, respectively. The Broselow tape had the greatest bias and least precision among the 4 methods. The Mercy, PAWPER XL-MAC, and PAWPER XL tapes had similar performance, but all performed significantly better than the Broselow tape in pairwise comparison. The best weight estimation method overall was the PAWPER XL tape as it also had the least bias and greatest precision.

CONCLUSIONS

The Mercy, PAWPER XL-MAC, and PAWPER XL tapes were more accurate than the 2017 Broselow tape and should be used in preference in Ghana and countries with similar population structure.