This paper aims to show how a simple performance test can be used to formulate a dose-equivalency metric to index driver-related performance deficits across different drugs, based on alcohol equivalency levels. It describes a series of interlocking studies, using graded alcohol doses and slightly different methodologies. Regression analysis is applied to the results of a battery of cognitive tests, so that performance deficit can be used to predict blood alcohol level. The first experiment was cross-validated by the second and third experiments. Using known relationships between the subtest of the battery to standardise tests of mental aptitude and achievement, similar regression equations can be used to index loss of mental acuity. It is now possible to index other drugs through this linear regression of subtest in the battery, so that the loss due to a specific drug can be compared with its equivalent alcohol dose or with the predicted change in mental potential as measured by a standardised test. The algorithms for these two indexing techniques are described, and applications to drugs and driving safety are discussed.
Abstract