This is the fourth and final CDEWS study in Washington, DC. CDEWS collects urine specimens already obtained and tested for a limited number of drugs by local organizations and sends them to a collaborating laboratory for testing for over 240 substances. The results provide programs with a snapshot of the types of drugs recently used by their tested populations and an idea of what drugs their routine test panels might be missing. For this study, we obtained 271 positive and negative urine specimens that had been collected from probationers and parolees in DC between July 2018 and February 2019. Among the more noteworthy findings were:
In spite of testing for 46 synthetic cannabinoid (SC) analytes, the CDEWS collaborating laboratory only detected synthetic cannabinoids (SC) in 47% of the specimens that the local agency said had tested positive for (SC). We subsequently sent the specimens to another laboratory capable of detecting over 300 SC analytes. The combined testing confirmed SC in 97% of the specimens. This experience highlighted for us the complexity in detecting the wide range of changing SC analytes and the need to understand the capabilities of the specific tests being used.
The test results for fentanyl (21% of + specimens) were of considerable interest to us in view of the declining trend in opiate positives among arrestees in DC, a group that tested positive for heroin in the past. The standard opiate screen detects morphine, a metabolite of heroin, but not fentanyl or its analogues. Perhaps heroin use had been supplanted by fentanyl? Our first CDEWS study in DC showed similar rates of opiate positives in arrestees and probationers, so we felt it reasonable to apply our estimates of fentanyl in probationers/parolees from the present study to arrestees. We estimate that only about 9% of the tested arrestees in DC would have tested positive for fentanyl or its analogues, suggesting that there was, in fact, not a large amount of the use of heroin or fentanyl in the arrestee population in DC.
The only drug test result that changed since our prior CDEWS study conducted three years earlier was for marijuana (37% to 58% of the positive sample, p<.01), a drug tested for by the local organization upon request of the probation officer. A change in recent marijuana use was expected, in view of the legalization of recreational use of marijuana in Washington, DC.
