The validity of self-reported marijuana and cocaine use

This article presents initial evidence on the validity of self-report interview data obtained from recently booked arrestees participating in the Drug Use Forecasting (DUF) program to identify factors associated with the accuracy of the DUF self-reports. In addition, this study examines issues surrounding the accuracy of self-reporting a relatively soft drug, such as marijuana, compared to a relatively hard drug, such as cocaine. The data were obtained from 4,080 arrestees in the DUF program in Omaha, Nebraska from 1987 to 1994. It was found that the accuracy of self-reported drug use varies considerably from one drug to another. In the case of a relatively soft drug, such as marijuana, the accuracy of self-reports may be less dependent on personal characteristics than on situational factors. When examining a relatively hard drug, however, such as cocaine, self-reports may be more influenced by both respondent characteristics and situational factors.