Area Model for Drug and Medical Testing

Author:
Kevin Dael
This is an area model of probabilities involved with drug use and drug testing. It can also be used for other medical testing situations. Move the sliders to change the percentage of drug use and the test accuracy. The result shows theoretical probabilities as a percentage for true negative, true positive, false negative, and false positive test indications.
Which result is most problematic, and for whom is this a problem?