Premium
To normalize or not to normalize? Fat is the question
Author(s) -
Hebert Craig E.,
Keenleyside Karen A.
Publication year - 1995
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620140509
Subject(s) - analysis of covariance , biota , covariance , environmental chemistry , chemistry , statistics , environmental science , mathematics , biology , ecology
Abstract Concentrations of lipophilic contaminants in biota are frequently corrected for variation in tissue lipid content. Usually, this correction is accomplished by dividing tissue contaminant concentration by lipid concentration to form lipid‐normalized data. This ratio‐based approach is satisfactory when contaminant concentration varies in direct proportion to lipid content. However, when such a relationship does not exist, erroneous conclusions may be reached. Recent research has emphasized the potential shortcomings of the use of ratio variables. We demonstrate the importance of considering these shortcomings when lipid‐normalizing data. Three examples are presented, and an alternative approach based upon the use of analysis of covariance (ANCOVA) is suggested.