Z Scores for Pediatric Echocardiography Dimensions Adjusted for Body Size, BMI, and Age.

BACKGROUND

Cardiovascular dimensions measured during pediatric echocardiograms must be normalized for body size. However, other variables may confound their interpretation, such as age and abnormal body habitus. This retrospective cross-sectional study of the Canadian Congenital and Pediatric Cardiology Research Network aimed to create Z score equations for commonly measured dimensions in pediatric 2-dimensional echocardiography that were free of residual confounding effects of body size, body mass index, and age.

METHODS

The reference sample consisted of >20 000 children without heart disease from 9 institutions who underwent clinical echocardiography that was reported as normal. A generalized additive model for location, scale, and shape (GAMLSS) was used to model the expected distributions of measurements as a function of sex, height, weight, body mass index, and age.

RESULTS

Compared with a model that only considered body surface area, the proposed Z scores demonstrated less bias in subgroups of overweight, young, and early school-aged children.

CONCLUSIONS

The proposed Z score equations may improve diagnostic and therapeutic accuracy by ensuring that body size, body mass index, and age do not confound the interpretation of measurements.