Hair testing and self-report of cocaine use by heroin users

Aim Failure to disclose cocaine use can have a negative impact on medical care and research validity. This study was performed to identify predictors of cocaine non‐disclosure among individuals who self‐reported heroin use during a medical care encounter. Design A prospective comparison of self‐report of cocaine use among heroin users and hair analysis for cocaine. Setting Four health‐care clinics at an academic, inner‐city hospital....