Drug actions depend on dose and intervals between doses, in ways that
are drug-specific and sometimes complex, complicating the use of drug
dosing histories as an explanatory variable in the analysis of clinica
l trials. We describe a spread-sheet method for conveniently displayin
g patients' drug dosing histories, to facilitate identification of dos
ing correlates of clinically important events. (C) 1997 by John Wiley
& Sons, Ltd.