Trends in drug testing. Is there evidence of more positive results in tests?

Drug-testing company Concateno is conducting more tests year on year. From January to July 2008, its Canary Wharf site alone conducted almost 20% more tests than during the same period last year. While the number of positive tests has increased, this rise is proportionate to the increase in the volume of testing. However, there are some subtle but noticeable developments. Industries with long-established testing policies (such as rail and oil) have traditionally had low positive rates, whereas newer industries typically produce high initial positive rates which decline with time, suggesting the deterrent value of a drug and alcohol testing policy.

Cocaine has shown a prolific rise in the past 10 years, albeit from a relatively low base. Since 1998, the number of positive cocaine tests has gone up 1,000%. The percentage of positive alcohol tests is staying at approximately the same level.

Another trend is the effect of transient labour. The rising number of workers from Eastern Europe has coincided with spikes in certain drug categories -- barbiturates, for example. This highlights the fact that drug usage is constantly changing, which in turn means that changes must be continually monitored and assessed to find the right solutions.