Drug screening and changing marijuana policy: Validation of new single question drug screening tools

Illicit drug use is common in U.S. medical settings. A validated Single Drug Screening Question (SDSQ) containing the word "illegal" is widely used. As marijuana policies change, the present wording may not perform as expected in states legalizing use. This study compares the performance of the validated SDSQ with three different SDSQ wordings.

Patients, 18 years and older, presenting to a U.S. hospital emergency department were asked to complete a survey containing the existing SDSQ, three new SDSQ versions without the word "illegal," and the Mini International Neuropsychiatric Interview. Patients were also encouraged to provide a sample for saliva drug testing.

Of 297 eligible patients, 200 (67.3%) completed the survey and 141 (70.5% of interview participants) completed saliva testing. Overlapping confidence intervals on the Area Under the Curve (AUC) analysis confirmed that sensitivities of all SDSQs were statistically similar for detecting self-reported drug use (65-71%). Combining questionnaire and saliva testing increased drug use detection by 2% and resulted in lower SDSQ sensitivity (58-67%). Specificities were 99-100%. The SDSQ with the highest sensitivity was: "In the last twelve months, did you smoke pot (marijuana), use another street drug, or use a prescription medication "recreationally" (just for the feeling, or using more than prescribed)?"

All four SDSQs demonstrated acceptable sensitivity and high specificity. Removing the term 'illegal' does not result in higher, or lower, reported drug use, though results could vary in states with legalized marijuana. Future research should replicate this study in one or more of these states.