Conversation so far:
where can you get a drug test done
The most common method of drug testing, urinalysis, can be done at the workplace (at a health unit), a doctor's office or any other site selected by the employer.
What is the purpose of the drug test
Drug testing requested by employers is to determine if employees or job applicants are using drugs. It can identify evidence of recent use of alcohol, prescription drugs and illicit drugs.

Question: Why are the results important
Self-contained rewrite: Why are the results of the drug test important to employers