Scientific study about Drug testing in the workplace

I was curious if there was evidence for drug testing improving productivity. I found a research article that pointed to many flawed studies and some surprising conclusions. https://www.ncbi.nlm.nih.gov/books/NBK236244/

1. However, as depicted in Figure 7.2, 76 percent of those who tested positive at preemployment had not been fired after 3 years, compared with 86 percent of those testing negative. This represents a 10 percent absolute difference between groups in retention rates, which appears to be less drastic than the reported 77 percent higher rate of firing. In other words, you can work even with drug use.

2. Here is some of the conclusions:

   The existing research on workplace drug testing and productivity offers limited and inconclusive evidence regarding the effectiveness of drug-testing programs in enhancing workplace productivity. Key points from the research include:

   1. Methodological Issues: The few studies on for-cause drug-testing suffer from significant methodological problems, making it difficult to assess their impact on productivity. There is also no published evidence evaluating the effects of random drug testing on productivity.
   2. Preemployment Drug Testing: Studies indicate that preemployment drug-test results can be valid predictors of certain job-related behaviors. Applicants who test positive are more likely to exhibit higher rates of absenteeism, turnover, and disciplinary actions compared to those who test negative. Positive test results are also predictive of future alcohol and drug problems.
   3. Predictive Validity: Positive preemployment drug test results are associated with a higher likelihood of referrals for alcohol and drug abuse problems and related medical claims. However, this does not necessarily mean that preemployment drug testing is a cost-effective selection program.
   4. Cost-Effectiveness: The cost-effectiveness and predictive validity of drug test results depend on the prevalence of drug use among job applicants. A test may become more or less useful over time as drug use patterns change.
   5. Testing Procedures: The studies reviewed generally used analytical procedures conforming to the National Institute on Drug Abuse guidelines. Many private organizations use less stringent methods, which may reduce the efficacy of their programs.
   6. Over-weighting Drug Test Results: There is a risk of employers giving too much importance to drug test results, potentially overlooking other important job-related criteria. The research does not conclusively show that applicants testing positive would perform worse than those who would have been hired in their place.
   7. Gap in Research: Existing studies do not examine the interaction between recent drug use and other job-related applicant characteristics. While preemployment drug testing is predicatively valid, many applicants who test positive could still be hired without causing job-related issues.

   Overall, while preemployment drug testing shows some predictive validity, the effectiveness and cost-efficiency of drug-testing programs in improving workplace productivity remain uncertain and context-dependent.

3. What is more costly? A worker on drugs or a worker that is fired not due to drug use and the cost of rehire? Drug testing has limited the pool of available workers, and increases the employment problem for segments of the population who may use marijuana or other drugs that are slowly becoming legalized.