How patients understand the term "nonmedical use" of prescription drugs: insights from cognitive interviews.

BACKGROUND: With rising rates of prescription drug abuse and associated overdose deaths, there is great interest in having accurate and efficient screening tools that identify nonmedical use of prescription drugs in health care settings. The authors sought to gain a better understanding of how patients interpret questions about misuse of prescription drugs, with the goal of improving the accuracy and acceptability of instruments intended for use in primary care.
METHODS: A total of 27 English-speaking adult patients were recruited from an urban safety net primary care clinic to complete a cognitive interview about a 4-item screening questionnaire for tobacco, alcohol, illicit drugs, and misuse of prescription drugs. Detailed field notes were analyzed for overall comprehension of the screening items on illicit drug use and prescription drug misuse, the accuracy with which participants classified drugs into these categories, and whether the screening response correctly captured the participant's substance use behavior.
RESULTS: Based on initial responses to the screening items, 6 (22%) participants screened positive for past-year prescription drug misuse, and 8 (30%) for illicit drug use. The majority (26/27) of participants correctly interpreted the item on illicit drug use, and appropriately classified drugs in this category. Eleven (41%) participants had errors in their understanding of the prescription drug misuse item. The most common error was classifying use of medications without abuse potential as nonmedical use. All cases of misunderstanding the prescription drug misuse item occurred among participants who screened negative for illicit drug use.
CONCLUSIONS: The results suggest that terminology used to describe misuse of prescription medications may be misunderstood by many primary care patients, particularly those who do not use illicit drugs. Failure to improve upon the language used to describe prescription drug misuse in screening questionnaires intended for use in medical settings could potentially lead to high rates of false-positive results.