There is a growing body of evidence that suggests there is a correlation between indicators of job performance and measures of drug use.
Research has demonstrated that some basic skills relevant to job performance are impaired by many drugs.
United States Navy study
A 1989 study of United States Navy recruits compared the staff retention rates of male recruits who had tested positive for marijuana at the time of induction, with a matched group who tested negative for any illicit drugs. When the two sample groups were balanced for other factors, staff retention rates for the drug negative group (81%) were significantly higher than for the drug positive group (57%) after 2.5 years.
United States Postal Service study
In 1987, a study was started that centred on 5,500 job applicants of the United States Postal Service. Overall, 9% of the new applicants tested positive. Over the next three years, several employment factors were monitored. After balancing for age, sex and race, the drug positive group showed the following results:
- 66% higher rate of absenteeism
- 77% higher rate of involuntary turnover
- 51% higher rate of filing medical claims, and an 83% higher average dollar amount for such claims
- 240% higher rate of disciplinary action