title: The log transformation is special.
abstract: The logarithmic (log) transformation is a simple yet controversial step in the analysis of positive continuous data measured on an interval scale. Situations where a log transformation is indicated will be reviewed. This paper contends that the log transformation should not be classed with other transformations as it has particular advantages. Problems with using the data themselves to decide whether or not to transform will be discussed. It is recommended that log transformed analyses should frequently be preferred to untransformed analyses and that careful consideration should be given to use of a log transformation at the protocol design stage.
authors.affiliation: Department of Medical Statistics, Glaxo Research and Development Ltd., Greenford, Middlesex, U.K.
authors.forename: O N
authors.initials: ON
authors.lastname: Keene
mesh_terms: D000704:Analysis of Variance; D002986:Clinical Trials as Topic / Q000706:statistics & numerical data*; D018592:Cross-Over Studies; D003627:Data Interpretation, Statistical; D004311:Double-Blind Method; D004341:Drug Evaluation / Q000706:statistics & numerical data; D005746:Gastric Emptying / Q000187:drug effects; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D016015:Logistic Models; D010599:Pharmacokinetics; D012107:Research Design; D018709:Statistics, Nonparametric; D013997:Time Factors
chemical_list: D006854:Hydrocortisone