Elucidation of the US urine specimen validity testing (SVT) policies and performance evaluation of five clinical parameters for pre-screening adulterants in Taiwan’s opiates urinalysis

Throughout the history of workplace drug testing, countless testees have attempted to subvert their drug test results to mask their use of illegal drugs. In order to reduce sample adulteration, the US Federal government has demanded all certified laboratories to conduct specimen validity tests (SVTs) on every specimen, namely, to pre-screen and pre-confirm as many adulterants as possible. This study was conducted to better understand the performances of five clinical urine parameters in pre-screening adulterants, taking opiates-containing urine specimens for example. Yet, this paper was also written to elucidate and recommend the US SVT policy to those who were unfamiliar with but might afterwards sprout the interest in the issue, especially those outside the States. Based on our experimental data, when used alone, none of the five parameters was all-sensitive to the seven tested Taiwan-produced adulterants in urine. However, the combinative use of the five parameters was able to pre-detect the abnormities caused by adulteration (but not to identify the adulterants themselves) or show different degrees of promise of the like, depending on the kind and amount of the adulterant added and how strict the criteria of adulteration recognition was. Considering the actual efficiency, we suggest conclusively that, while retaining and complying with those strict Department of Health and Human Services (HHS) provisions for reporting “adulterated,” “substituted,” “dilute,” or “invalid result,” each laboratory just cover as many clinical parameters and physical characteristics of urine and place more emphasis on using these parameters and characteristics as indicators with reasonably tolerant criteria to probably trigger additional specific SVTs that then confirm as many adulterants as possible. Meanwhile, from the standpoint of scientific and forensic validity, the importance of SVT data quality cannot be overemphasized. In order to meet the strict and rigid criteria, relevant instruments, especially those for the confirmatory tests, must be appropriately upgraded. Another interesting finding in this study was that nitrite could test for not only nitrite-containing adulterants but also nonnitrite oxidizing adulterants.