title: Assessment of the mean-value of 17-hydroxypregnenolone in the umbilical blood of newborns by the exploratory analysis of biochemical data.
abstract: 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.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemical Technology, Pardubice University, CZ-532 10 Pardubice, Czech Republic. milan.meloun@upce.cz
authors.forename: Milan
authors.initials: M
authors.lastname: Meloun
authors.forename: Martin
authors.initials: M
authors.lastname: Hill
authors.forename: Jirí
authors.initials: J
authors.lastname: Militký
authors.forename: Karel
authors.initials: K
authors.lastname: Kupka
mesh_terms: 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
chemical_list: D006907:17-alpha-Hydroxypregnenolone