1. Introduction
Although no method for measuring patients’ drug use is
perfect, the home-inventory method is usually seen as the
gold standard. Patients’ ability to ‘‘self-report’’ drug use
accurately has received a mixed response. Some studies
have reported high levels of agreement between self-reporting
and other methods [1e3]. Other studies have been less
supportive of the practice [4]. A previous article addresses
some of the benefits and drawbacks of self-reporting [5];
for example, accuracy and recall in the self-report of drug
use depend on a number of factors, such as interviewer
skills, length of recall period, and class of drug. Benefits
of self-report can include the use of over-the-counter