title: Debunking the Idea that Ligand Efficiency Indices Are Superior to pIC50 as QSAR Activities.
abstract: Several papers have appeared in which a ligand efficiency index instead of pIC50 is used as the activity in QSAR. The claim is that better fits and predictions are obtained with ligand efficiency. We show on both public-domain and in-house data sets that the apparent superiority is a statistical artifact that occurs when ligand efficiency indices are correlated with the physical property included in their definition (number of non-hydrogens, ALOGP, TPSA, etc.) and when the property is easier to predict than the original pIC50.
authors.affiliation: Modeling and Informatics Department, Merck & Co. Inc. , Rahway, New Jersey 07065, United States.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Sheridan
mesh_terms: D006801:Humans; D020128:Inhibitory Concentration 50; D008024:Ligands; D021281:Quantitative Structure-Activity Relationship
chemical_list: D008024:Ligands