Table 1: summary of the evidence evaluated: the direct and indirect evidence for each topic is displayed; there is very little evidence on any aspect of weight estimation other than accuracy, much of which is of low grade
	Healthcare provider Guess	Parental Estimate	Age-based formulas	Broselow Tape	Mercy Method	PAWPER XL Tape
Accuracy of weight estimation systems for estimating TBW	Very inaccurate - should not be used	Accurate if parent has a recent weight (especially if child weighed in their presence)	Very inaccurate - should not be used	Inconsistent across populations, has low-intermediate accuracy and probably should not be used	Very accurate across a wide range of populations; not evaluated in very obese populations	Very accurate across a wide range of populations, moderately accurate in severely obese children
Performance of weight-estimation systems in underweight populations	No evidence	Limited evidence; similar results to normal weight populations	Overestimate weight significantly	Overestimates weight substantially	Very accurate	Very accurate
Performance of weight-estimation systems in obese populations – estimation of TBW	No evidence	Not accurate in overweight and obese children (indirect evidence)	Underestimate weight significantly	Underestimates TBW substantially	Accurate except in severely obese patients	Moderately accurate, less accurate than the Mercy method
Performance of weight-estimation systems in obese populations – estimation of IBW	No evidence	No evidence	The European Paediatric Life Support formula predicts IBW with moderate accuracy	The tape can provide an accurate estimate of IBW in obese children	Cannot estimate IBW	Estimates IBW very accurately, simultaneously with TBW
Training requirements for weight-estimation systems	No evidence	No evidence	Easily forgotten	Very high incidence of errors in simulation studies	Higher errors with less experienced raters	Decreased accuracy if habitus scoring performed poorly
Performance of weight-estimation systems under stressful conditions	No evidence, but unlikely to be better than study conditions	Unknown, but of concern	Calculation errors higher under stressful conditions	Unknown, errors more likely than during simulation studies	Unknown	Unknown
Weight estimation systems and integration with resuscitation aids	No integration	No integration	No integration	Has only been studied with the use of supplementary reference materials	No designated integration	Designed to be used with colour-coded materials; linked to the Flipper card, EDDC book and/or EDD4Children app
Cognitive burden of weight estimation systems	No evidence	No evidence	Calculation errors are common in all levels of healthcare providers – may make age-formulas unreliable	Negligible burden for weight-estimation; supplementary material required for drug dosing information	Calculation errors are common in all levels of healthcare providers – may make Mercy method unreliable	Negligible burden; supplementary material required for drug dosing information