Objectives: To validate the recently described Mercy method for weight estimation in an independent cohort of children living in the United States.
Methods: Anthropometric data including weight, height, humeral length, and mid upper arm circumference were collected from 976 otherwise healthy children (2 months to 14 years old). The data were used to examine the predictive performances of the Mercy method and four other weight estimation strategies (the Advanced Pediatric Life Support [APLS] method, the Broselow tape, and the Luscombe and Owens and the Nelson methods).
Results: THE MERCY METHOD DEMONSTRATED ACCURACY COMPARABLE TO THAT OBSERVED IN THE ORIGINAL STUDY (MEAN ERROR: -0.3 kg; mean percentage error: -0.3%; root mean square error: 2.62 kg; 95% limits of agreement: 0.83-1.19). This method estimated weight within 20% of actual for 95% of children compared with 58.7% for APLS, 78% for Broselow, 54.4% for Luscombe and Owens, and 70.4% for Nelson. Furthermore, the Mercy method was the only weight estimation strategy which enabled prediction of weight in all of the children enrolled.
Conclusions: The Mercy method proved to be highly accurate and more robust than existing weight estimation strategies across a wider range of age and body mass index values, thereby making it superior to other existing approaches.
Keywords: adolescent; body weight; child; developing countries; infant; life support.