The validity of self-reported opiate and cocaine use by out-of-treatment drug users

The objective of this study was (I) to assess the validity of self-report measures of opiate and cocaine use for a sample of out-of-treatment drug users by comparing self-reports to urinalysis results, and (2) to examine the correlates of valid self-reports. Baseline data were collected from 1, 015 out-of-treatment drug users in Philadelphia as part of an HIV risk reduction intervention project funded by the National Institute on Drug Abuse. Agreement rates, sensitivity, and specificity measurements were high, and kappa values were good indicating that out-of-treatment drug users provided moderately valid self-reported drug use. The multivariate analysis revealed that women and younger persons were more likely to validly report opiate use and those who were younger and more educated were more likely to give valid reports of cocaine use. Additional research is needed to better understand differences in the validity of self-reports of opiate and cocaine use and the role that urinalysis plays in influencing the validity of self-reported data.