Assessment of the mean-value of 17-hydroxypregnenolone in the umbilical blood of newborns by the exploratory analysis of biochemical data.
The main aim of data analysis in biochemical metrology is the extraction of relevant information from biochemical data measurements. A system of extended exploratory data analysis (EDA) based on the concept of graphical tools for sample data summarization and exploration is proposed and the original EDA algorithm in S-Plus is available on the Internet at http://www.trilobyte.cz/EDA. To check basic assumptions about biochemical and medical data is to examine the independence of sample elements, sample normality and homogeneity. The exact assessment of the mean-value and the variance of steroid levels in controls is necessary for the correct assessment of the samples from patients. Data examination procedures are illustrated by a determination of the mean-value of 17-hydroxypregnenolone in the umbilical blood of newborns. For an asymmetric, strongly skewed sample distribution corrupted with outliers the best estimate of location seems to be the median. The Box-Cox transformation improves a sample symmetry. The proposed procedure gives reliable estimates of a mean-value for an asymmetric distribution of 17-hydroxypregnenolone when the arithmetic mean can not be used.
Meloun
Milan
M
Department of Analytical Chemistry, Faculty of Chemical Technology, Pardubice University, CZ-532 10 Pardubice, Czech Republic. milan.meloun@upce.cz
Hill
Martin
M
Militký
Jirí
J
Kupka
Karel
K
D006907:17-alpha-Hydroxypregnenolone / Q000097:blood*; D000465:Algorithms; D019295:Computational Biology; D003627:Data Interpretation, Statistical; D005312:Fetal Blood / Q000737:chemistry*; D006801:Humans; D007231:Infant, Newborn; D008432:Mathematical Computing; D018401:Sample Size; D012984:Software
D006907:17-alpha-Hydroxypregnenolone