Both these findings could be related to the difficulty of use and interpretation of results. Neither test should be considered as performing well enough for routine use in specialist services. In particular the low saliva/plasma ratio for benzodiazepines (0.3) as compared with basic drugs such as opiates (6-MAM = 6) and amphetamines (2.8) has led some authors to conclude that oral testing is currently suitable for amphetamines and opiates, but not for benzodiazepines (Gronholm & Lillsunde, 2001). There may be a place for the use of saliva testing in individuals who are regularly unable to provide urine samples, and in this case the Cozart Rapiscan test would be preferred, due to its relatively low false positive rate.

3. Laboratory oral fluid and oral mucosal transudate tests: illicit substances.

There may be a limited place for laboratory testing for clients who query an on-site oral fluid test result. This is a rapidly developing area and oral fluid or oral mucosal transudate have the potential to replace urine as the gold standard matrix in the future.