“…Self-report of illicit drug use compared to urinalysis typically produces good validity findings (15–19); however, specific prescription opioids used in a nonmedical manner (e.g., Vicodin, OxyContin) may be viewed differently by users as they are commonly prescribed (e.g., government approved, pharmaceutical grade pills) and thus different from other “street” drugs. Furthermore, underreporting of nonmedical opioid use has been found to be common in some populations (e.g., among pregnant women, those who are dependent, veterans, adolescents) (20–25), but underreporting may also be due, in part, to confusion regarding which drugs are opioids, or in regard to medical versus nonmedical/recreational use. A study assessing validity of using a self-report questionnaire compared to self-report via identification of specific opioids from color photographs found that validity was higher for OxyContin, but lower for generic extended-release oxycodone (ƙ = 0.62 and 0.46, respectively) when compared to some other opioids, such as methadone wafers/disks, methadone tablets, or Dilaudid (9), suggesting that reporting of use of individual types of opioids may not always be reliable.…”