We compared performance characteristics of 7 weight estimation methods examining predictive performance and human factors errors.
This was a prospective study of 80 emergency care providers (raters) and 80 children aged 2 months to 16 years. Raters estimated weights in 5 children with the following 7 strategies: visual estimation, Advanced Pediatric Life Support, Luscombe and Owens, Broselow tape, devised weight estimation method, 2D Mercy TAPE (2DT), and 3D Mercy TAPE (3DT). Quantitative errors were determined by checking rater values against values returned with optimal method use.
Four hundred rater-child pairings generated 2800 weight estimates. For all methods, rater-estimated weights were less accurate than weights derived by optimal application. Skill-based, perception, and judgment/decision error were observed. For visual estimation, weights were underestimated in most children. For Advanced Pediatric Life Support/Luscombe and Owens, order of operations markedly impacted errors with 23% of calculations requiring addition first performed incorrectly versus 9% of calculations requiring multiplication first. For Broselow tape, only 63% of cases were eligible for estimation with this device, yet raters assigned a weight in 96% of cases. For Devised Weight Estimation Method, 96% of overweight and 48% of obese children were classified as slim or average. For 2DT/3DT, the 2DT was prone to more errors most commonly use of the wrong side of the device (24%). The impact of rater characteristics on error was most pronounced for methods requiring calculation.
Skill-based, perception, or judgment errors were observed in more than 1 of 20 cases. No singular strategy was used with 100% accuracy.