Estimating the weight of ethnically diverse children attending an Australian emergency department: a prospective, blinded, comparison of age-based and length-based tools including Mercy, PAWPER and Broselow

Abstract

ObjectiveTo prospectively compare the actual weights of Australian children in an ethnically diverse metropolitan setting with the predicted weights using the Paediatric Advanced Weight Prediction in the Emergency Room (PAWPER) tape, Broselow tape, Mercy system and calculated weights using the updated Advanced Paediatric Life Support (APLS), Luscombe and Owens and Best Guess formulae.MethodsA prospective, cross-sectional, observational, blinded, convenience study conducted at the Children's Hospital at Westmead Paediatric Emergency Department in Sydney, Australia. Comparisons were made using Bland-Altman plots, mean difference, limits of agreement and estimated weight within 10% and 20% of actual weight.Results199 patients were enrolled in the study with a mean actual weight of 27.2 kg (SD 17.2). Length-based tools, with or without body habitus adjustment, performed better than age-based formulae. When measuring estimated weight within 10% of actual weight, PAWPER performed best with 73%, followed by Mercy (69%), PAWPER with no adjustment (62%), Broselow (60%), Best Guess (47%), Luscombe and Owens (41%) and revised APLS (40%). Mean difference was similar across all methods ranging from 0.4 kg (0.0, 0.9) for Mercy to −2.2 kg (−3.5, −0.9) for revised APLS. Limits of agreement were narrower for the length-based tools (−5.9, 6.8 Mercy; −8.3, 5.6 Broselow; −9.0, 7.1 PAWPER adjusted; −12.1, 9.2 PAWPER unadjusted) than the age-based formulae (−18.6, 17.4 Best Guess; −19.4, 15.1 revised APLS, −21.8, 17.7 Luscombe and Owens).ConclusionIn an ethnically diverse population, length-based methods with or without body habitus modification are superior to age-based methods for predicting actual body weight. Body habitus modifications increase the accuracy and precision slightly.

A validation study of the PAWPER XL tape: accurate estimation of both total and ideal body weight in children up to 16 years of age

“…The original PAWPER tape achieved an exceptionally high overall level of accuracy in this study sample, similar to that previously reported from non-obese populations [6,23,24]. The accuracy in obese children was poor, however, similar to previous findings from studies in populations with a high prevalence of obesity [4,5].…”

“…These findings echo previous studies in which these three methods have been compared [5,6,23]. Given the consistently higher accuracy of the dual length-and habitus-based weight estimation systems (such as the Mercy method and the PAWPER tapes) when compared with length-only systems (such as the Broselow tape) it is hard to justify the continued use of the Broselow tape.…”

“…The need for a modification of the original PAWPER system became apparent from the results of local and international research [4][5][6]. While the PAWPER system still proved to be more accurate than other weight estimation systems in these studies, some limitations of the tape were identified.…”

Development and validation of a method to estimate body weight in critically ill children using length and mid-arm circumference measurements: The PAWPER XL-MAC system

“…[10,11] However, recent studies on the original PAWPER tape in very obese populations, and with novice users, failed to show the degree of accuracy reached in studies in less obese populations. [8,10,[12][13][14] An important contributor to the reduced accuracy of the PAWPER tape was inaccurate assessment of body habitus in these obese children. [12,15] The development of a less subjective and more standardised method of assessing habitus could therefore potentially improve the functioning of the PAWPER system in different populations and with users of different experience.…”

Authors' Response

“…Some studies have shown that the Pediatric Advanced Weight Prediction in the Emergency Room (PAWPER) tape is more accurate in predicting the correct weight as compared to Broselow tape345; others have suggested that the PAWPER tape has not been able to replicate its initial impressive performance6 and that none of the currently available methods is optimum5. Adjusting the estimated weight based on body habitus seems to be theoretically advantageous, but Georgoulas and Wells4 have stated that such adjustments have had only a minimal impact on the overall performance of the PAWPER tape.…”