Beside the policy, the procedures to perform the test and how to randomly pick up the worker for the test must crystal clear , cannot just do a selective random check up only.
The lab. where the test done must have a high quality standard with recognition by an international body such as NATA. The appointed person who collects the urine and the doctor who interpretes the result must have a proper training in this field of specialisation. In Malaysia, SOEM-MMA regularly conduct a MRO course for doctors.