The Why and How of Z Scores
2012; Elsevier BV; Volume: 26; Issue: 1 Linguagem: Inglês
10.1016/j.echo.2012.11.005
ISSN1097-6795
Autores Tópico(s)Blood Pressure and Hypertension Studies
ResumoThe use of echocardiographic measurements to detect disease and predict outcomes can be confounded by a number of nondisease factors, including the effect of body size, that contribute to the variance of these measurements. The process of normal growth is associated with a nearly 200-fold increase in normal left ventricular end-diastolic volume (EDV) from premature infants up to large adolescents, making it imperative to account for changes in body size in pediatrics. Although this issue is often ignored in adult echocardiography, the sensitivity and specificity of parameters of left ventricular size are significantly improved when adjustment for body size in adults is performed. 1 De Simone G. Daniels S.R. Devereux R.B. Meyer R.A. Roman M.J. De Divitiis O. et al. Left ventricular mass and body size in normotensive children and adults: assessment of allometric relations and impact of overweight. J Am Coll Cardiol. 1992; 20: 1251-1260 Abstract Full Text PDF PubMed Scopus (1504) Google Scholar The article by Mawad et al.2 Mawad W. Drolet C. Dahdah N. Dallaire F. A review and critique of the statistical methods used to generate reference values in pediatric echocardiography. J Am Soc Echocardiogr. 2013; 26: 29-37 Abstract Full Text Full Text PDF PubMed Scopus (63) Google Scholar in this issue of JASE addresses an important aspect of this process, although it is likely a topic that is unfamiliar to most echocardiographers, even those in pediatric cardiology who rely heavily on Z scores. The concept of Z scores itself is often unfamiliar to adult echocardiographers. CorrectionJournal of the American Society of EchocardiographyVol. 26Issue 4PreviewIn the article, "The Why and How of Z Scores," by Colan, J Am Soc Echocardiogr 2013;26:38-40, the second sentence in the first paragraph on page 40 contains an error. The correct sentence should be "We undertook a comprehensive exploration of this issue5 and found that both theoretical considerations and empirical observations indicated that BSA is superior to height or weight alone as an allometric variable in normal subjects, that the Haycock formula7 for BSA was superior to the other published formulas, and that exponential equations of the form Y = α x BMIb + c provided the best descriptor for all anatomic cardiac measurements. Full-Text PDF
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