In Australia and many countries, drug testing which is required for legal purposes (for example; workplace testing, where a positive test involves a penalty or dismissal), requires confirmatory testing to be performed. In Australia this would require compliance with Australian Standard AS 4308. The use of POCT for drugs of abuse in both medical and non-medical settings raises many issues, including; operator training, quality control, quality assurance, accuracy of results, limitations of the technology and economics. In particular, POC drug testing is generally designed to screen for the presence of designated drugs or groups of drugs. None are intended to serve as a definitive or confirmation test.
Both AS/NZS 4308:2008 Procedures for specimen collection and the detection and quantitation of drugs of abuse in urine and AS 4760:2006 Procedures for specimen collection and the detection and quantitation of drugs in oral fluid outline the procedures required for a laboratory to demonstrate its technical competency. They are prescriptive in the procedures required to ensure appropriate specimen collection, handling, storage, transport, on-site screening, the use of quality control and proficiency testing, initial testing and confirmatory testing.
The procedures are intended for (but not limited to) medico-legal, workplace, correctional services or court directed testing, of any or all of the following classes of drugs:
- amphetamine type substances.
- cannabis and metabolites.
- cocaine and metabolites.
The Standards cover all aspects of specimen collection and testing, and defines procedures which must be followed to allow proper legal scrutiny. These procedures include:
- specimen collection, storage, handling and dispatch (chain of custody)
- integrity and identity of the specimen
- general laboratory requirements
- laboratory screening procedures and test cut-off levels (cut-off drug concentrations), recording of results and reporting
- laboratory security, specimen reception, specimen integrity and storage
- quality control and proficiency testing (external quality assessment)
- laboratory confirmatory procedures
- laboratory personnel and training
Articles describing the relevance of POCT to drug detection and clinical toxicology with comments on the relevant quality issues have been published by Mighani108, Watson109 and Valdes etal110.