Qualitative, Quantitative (Cause-Effect): You are the Chief Operating Officer of a hospital. The Human Resources Director reports to you. Two of your valued Directors have a random drug screening for controlled substances with a group of hospital cohorts, and the result comes up as positive for heroine. Your experience with epidemiology and your understanding of cause-effect makes you skeptical of these general screening results. You request that the specimens be sent out to a specialty lab for confirmatory testing with gas chromatography specific for heroine. The results of the confirmatory testing show that both Directors are negative (0 mg/dl) for all control substances, including heroine. A further investigation revealed that both Directors attended a morning meeting the day of the random test and had eaten poppy seed muffins. You do research and find that poppy seed muffins produce a byproduct in the body that mimics opiates/heroine in a screening.

Discuss why these results occurred , i.e., the two very different results between a screening, and the confirmatory test in terms of a) qualitative and b) quantitative testing, c) specificity, d) reliability.