Preemployment drug screening. The epidemiologic issues

Area of Science:

• Occupational health
• Epidemiology
• Public health

Background:

• Drug testing for employment is a complex decision with legal, ethical, and economic implications.
• Understanding the epidemiologic factors is crucial for informed decision-making regarding workplace drug screening.

Purpose of the Study:

• To examine the epidemiologic issues surrounding preemployment drug screening.
• To evaluate the associations between drug screening results and workplace outcomes.
• To analyze the cost-benefit and predictive value of drug screening.

Main Methods:

• Review of two studies from the United States Postal Service on preemployment drug screens.
• Analysis of associations between positive drug screens and turnover, absenteeism, accidents, injuries, and discipline.
• Cost-benefit analysis incorporating outcome costs and drug use prevalence.
• Evaluation of the predictive value of positive drug screens based on prevalence.

Main Results:

• Associations between positive preemployment drug screens and negative workplace outcomes (turnover, absenteeism, accidents, injuries, discipline) were weaker than anticipated.
• Cost-benefit analyses indicate that savings from drug screening are contingent upon both the costs of adverse outcomes and the prevalence of drug use.
• The predictive value of a positive drug screen is significantly influenced by the prevalence of drug use, with low prevalence populations yielding a higher proportion of false positives.

Conclusions:

• The effectiveness and financial benefits of preemployment drug screening are not universally guaranteed and are highly dependent on the specific context, particularly the prevalence of drug use.
• A low prevalence of drug use in a screened population can substantially decrease the accuracy of positive drug test results, leading to a higher likelihood of false positives.