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About Z-Scores (in general)

According to the American Society of Echo's Guidelines and Standards for Performance of a Pediatric Echocardiogram:

In addition to reporting the absolute values, it is useful to report quantitative measures within the context of age- or size-appropriate norms (eg, z-score values).

A z-score indicates:

how many standard deviations an observation is above or below the mean. It allows comparison of observations from different normal distributions, which is done frequently in research.

(See the Wikipedia entry for more information about z-scores.)Concerning the application of z-scores to pediatric cardiology, interested persons should read:

• the invited editorial Establishing norms for echocardiographic measurements of cardiovascular structures and function in children
• the original article Theoretical and empirical derivation of cardiovascular allometric relationships in children
• the excellent chapter in Nadas' Pediatric Cardiology: Methodological Issues in Clinical Research
• the recent work, A Novel Method of Expressing Left Ventricular Mass Relative to Body Size in Children
• other recent works:
• A Review and Critique of the Statistical Methods Used to Generate Reference Values in Pediatric Echocardiography. (2012)
• Limitations of current echocardiographic nomograms for left ventricular, valvular, and arterial dimensions in children: a critical review. (2012)

About Me

My name is Dan Dyar. Among many other things, I am a Pediatric Cardiac Sonographer. Having worked in this field since Before The Internet, I sometimes observe the collision of technology and information in this field and am astonished by the disparity: we are simultaneously incredibly advanced and desperately primitive.
I hope this website helps soften these collision.
Should you wish to contact me, fill out the form here and hope for the best.

Disclaimer

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