About 14% of all substance abuse urine tests are positive for 1.2 substances. Cannabinoid and cocaine metabolites are most frequently the cause of positivity. Individuals in probation or parole programs have the highest numbers of positive urine substance abuse tests. Our data suggest that a consistency of positivity exists for substance abuse urine tests and that this positivity, once developed by testing laboratories, can be used for purposes of contractual relations and cost predictions. Valuable educational information that may assist the population serviced by the laboratory in regard to substance abuse can also be obtained.