Drug of abuse detection is a two-step process. The first step involves the initial screening of an illicit drug, suggesting that an illicit drug may be present in the system. The second step is a confirmatory test— done in laboratory to quantitatively determine and confirm the presence of an illegal drug. Screening tests are not as accurate as laboratory tests and have a greater propensity to provide inaccurate results. Some food items and medications may cause the screen test to inaccurately read positive, such as poppy seeds, diet pills, inhalers, and cough syrup. One should consult with their physician to better understand how a particular medication can interfere with the test results.