The validity of adult arrestee self-reports of crack cocaine use

Despite the many problems associated with crack use, little validated empirical evidence about the prevalence of crack cocaine exists. Researchers that track crack cocaine use have relied on self-reports to differentiate crack and powder cocaine. Prior research suggests that the accuracy of self-reports for the use of a variety of illicit substances is relatively low. To examine the validity of self-reports of crack use, this article employs a newly developed technology to detect specifically the presence of markers of crack cocaine in urine specimens. With a sample of 2327 arrestees from six cities that participate in the Arrestee Drug Abuse Monitoring (ADAM) Program, both face-to-face interview and urinalysis data were examined. Using a positive urinalysis result as the validity standard, we assessed the extent to which arrestees underreport crack cocaine use as compared to the use of marijuana, opiates, and methamphetamine. Logistic regression models were also developed to predict the factors that relate to underreporting. The results showed a considerable amount of underreporting for all the drug measures. In most cases, only about half the people who had a positive urinalysis test for drugs admitted using drugs. Overall, the least amount of underreporting occurred for the use of marijuana (63.6% told the "truth"), followed by methamphetamine (56.1% told the truth), crack (48.2% told the truth), and opiate (45.9% told the truth). Female crack users, as compared to male crack users, were more likely to admit using crack. Black arrestees were more likely to admit using crack than white or Hispanic arrestees. Arrestees with a history of prior drug treatment or a prior arrest, as compared to those without such histories, were more likely to admit using crack. The older the arrestee was, the more likely the arrestee would admit using crack. The more money an arrestee spent on drugs, the more likely the arrestee would admit using crack. Differences in underreporting were also observed across the six cities in this study. The implications of these findings for the monitoring of crack use are discussed.