A number of independent studies examine the efficacy of the DrugWipe, particularly for its lack of sensitivity for detecting Cannabis (delta-9-thc) which the Australian National Health Survey 2009 listed as the most frequently used illicit drug at 10.4% with 36% smoking at least once a week or more in 2016. Independent field testing of the DrugWipe in Finland recorded a high rate of false negatives, particularly for Cannabis, this is where a person tests negative however had recently used 14.4%. including sensitivity of less than 50%. According to statistics by the National Institute for Health and Welfare in Finland, of positive results for cannabis, cocaine and opioids, two-thirds were false when comparing against blood samples. As positive test results have been used as sufficient grounds for a ban on driving, the Finnish Parliamentary Ombudsman issued a statement condemning the practice.