Table 1:

Characteristics of the models used for comparison.

Model Characteristics
Z-Score Model	PHN1	Boston20	Italy2	Detroit6
Reference	Lopez, 2017	Boston Z-Scores*	Cantinotti, 2017	Pettersen, 2008
Model Regression#	y = m×BSAα	y = m×BSAα (y = β + m×BSAα for the coronary arteries)	ln(y) = b + (m×ln[BSA])	ln(y) = b + (m1×BSA) + (m2×BSA2) + (m3×BSA3)
Data Source	19 centers	1 center	1 center	1 center
Sample Size	3215	>2000	1151	782
Study Population	1) Weight-forlength Z <2 if <2 years old 2) BMI < 95th percentile if ≥2 years old 3) Gestational age ≥37 weeks 4) No structural or congenital heart disease 5) No systemic disorder with cardiovascular manifestations 6) No family history of left heart disease or cardiomyopathy	1) Weight >2.5 kg 2) BSA >0.18 m2 3) −2 > BMI Z > 2 4) No premature babies 5) No structural or congenital heart disease 6) No systemic disorder with cardiovascular manifestations 7) No family history of left heart disease or cardiomyopathy	1) Weight-forlength Z <2 if <2 years old 2) BMI < 95th percentile if ≥2 years old 3) Premature babies included 4) No structural or congenital heart disease 5) No systemic disorder with cardiovascular manifestations 6) No family history of genetic cardiac disease	1) No obese subjects 2) BSA <2 m2 3) No reference to gestational age or BMI 4) No structural or congenital heart disease 5) No systemic disorder with cardiovascular manifestations 6) No family history of genetic cardiac disease
Race Data	Multiracial	Not reported	Caucasian	Not reported
Observers	2	Multiple	1	Multiple

(BMI = body mass index, BSA = body surface area, PHN = Pediatric Heart Network).

^*The original publication from Boston involved only 496 children (8), but the regression equations used for comparison in this study were based on data from >2000 children with variable sample sizes for each parameter.¹⁹

^#y = measurement value; b = intercept; m, m₁, m₂, m₃ = slope values.