"...these could easily be included in echocardiography software, which would allow automated generation of an LV mass-for-height z score and percentile for each child undergoing echocardiography."
A Novel Method of Expressing Left Ventricular Mass Relative to Body Size in Children [link]
Bethany J. Foster, MD, MSCE; Andrew S. Mackie, MD, SM; Mark Mitsnefes, MD; Huma Ali;
Silvia Mamber, MD; Steven D. Colan, MD
Circulation. 2008;117:2769-2775 Published online before print May 19, 2008
Apart from debunking the practice of simply indexing LV mass by dividing mass by height, the "novel method" is the LMS (lambda, mu, sigma) method of analysis. While I couldn't paint my way out of a Box-Cox transformation, I get the idea: the lambda (power transformation to deal with skew), mu (mean), and sigma (coefficient of variation) are determined for each of many groups, elegantly- and deliberately- addressing the matters of skewness and heteroscedasticity.
Lots to read up on with this technique:
- The LMS method for constructing normalized growth standards [link]
- Smoothing reference centile curves: the LMS method and penalized likelihood [link]
- download LMS chart-making software from Tim Cole's website
The authors acknowledge that their data should not be taken to represent the definitive model of LV mass reference values, only that they are proposing the LMS technique as an alternate, superior, method.
Note: LV Mass was estimated from m-mode using the Devereux equation.
