Incidence and predictors of screen failures due to positive urine tests for alcohol, drugs of abuse, and cotinine among normal healthy research volunteers (NHRVs): analysis of data from 687 NHRVs screened at a large clinical pharmacology unit in the United States

Accurate medical histories for all NHRVs screening to participate in clinical pharmacology trials are vital to ensure volunteers' safety, and integrity of study results. Evidence from previous studies illustrate the potential for NHRVs to misrepresent their histories, especially when monetary incentives are offered, and the need to objectively verify these self-reported histories whenever practical. This study demonstrates that among the sample participants, all of whom self-reported a negative history of drug and alcohol abuse and tobacco smoking, 16% failed urine testing for either alcohol and drugs of abuse (6%), or cotinine (11%). Male sex and increased number of screenings in the preceding 12 months were significantly associated with increased odds for urine screen failure whereas increased enrollments in the same time period and increased study stipend decreased the same odds. These results emphasize the importance of diligently screening NHRVs participating in phase I clinical trails.