New age-based weight estimation formulae for Japanese children

Area of Science:

• Pediatric Emergency Medicine
• Clinical Pediatrics
• Biostatistics

Background:

• Accurate weight estimation is vital for pediatric emergency care, but time constraints often prevent direct weighing of critically ill children.
• Existing age-based weight estimation formulas lack specificity for Japanese children.
• This study addresses the need for a tailored weight estimation tool for Japanese pediatric populations.

Purpose of the Study:

• To develop and validate novel age-based weight estimation formulas specifically for children residing in Japan.
• To enhance the accuracy of emergency drug and equipment dosing in Japanese pediatric critical care.
• To provide a culturally specific tool for pediatric weight assessment.

Main Methods:

• Utilized a large dataset of 370,980 bodyweight measurements from 39,547 children (12-155 months) from the Longitudinal Survey of Babies in the 21st Century.
• Developed the Japanese Pediatric Assessment of Normal weight (JAPAN) formulas using 75% of the data.
• Validated the JAPAN formulas against the Park et al. and Nelson formulas using the remaining 25% of data, calculating mean absolute error and RMSE.

Main Results:

• The JAPAN formulas demonstrated superior performance in estimating Japanese children's weight compared to existing international formulas.
• Mean absolute error and Root Mean Square Error (RMSE) for the JAPAN formulas were 0.83 kg and 1.08 kg, respectively.
• The Park et al. formula, designed for Korean children, showed poor accuracy when applied to the Japanese cohort.

Conclusions:

• The newly developed JAPAN formulas are validated and suitable for age-based weight estimation in children living in Japan.
• These formulas offer a significant improvement for emergency medical situations requiring accurate pediatric weight assessment.
• The JAPAN formulas are recommended for clinical use in Japan to optimize resuscitation and treatment protocols.