s a result, drug tests mainly identify drug users who may have used a drug on the weekend, as they might use alcohol, and who are not under the influence of a drug while at work or when tested. It takes several hours for drug metabolites to appear in urine, so drug tests may miss drug users who are under the influence of drugs at the time the test is given.
Using the Kaiser Permanente data, researchers found no significant differences between health care costs for marijuana users to non-users.