Why is it a good idea for a company to control drug and alcohol abuse with its employees? What is the best approach to limiting workplace substance abuse? If you suspect an employee is using drugs or alcohol because their performance has declined, they have been tardy or absent, or their are complaints from co-workers, what should you do?

Companies should attempt to limit substance abuse of workers because compared to nonabusers, alcoholic employees and drug abusers are significantly less productive, ten times more likely to be absent, and three times more likely either to have or to cause an accident.
One of the effective ways to limit workplace substance abuse is by using drug testing. However, drug testing is not a cure, it may reduce drug use but employee drug abuse may still remain.
Because alcoholics and drug abusers are protected from employment discrimination by the law, the best way to control workplace substance abuse is through referral and rehabilitation. Don't make accusations about alcohol or drug abuse. Instead, attempt to get the employee to admit to the problem and then refer them to professionals.