It is worth noting that 'RR' in the title of our article is indeed 'relative risk' but that there is no statistical inference associated with our use of this term.
Also, I am grateful to Ross Bearman and others for pointing out some typos / errors in our paper - namely: The introduction states cannabis is a class C drug, the correct designation of class B is listed in table 1.
Figure 2 identifies methylphenidate as class C (should be class B)
Figure 3 identifies benzodiazepines as class B (class C)
Figure 3 methylphenidate as not classified (class B) All three charts identify: Ketamine as class B (class C) Buprenorphine as class B (class C) Dihydrocodeine as class C (class B) Amphetamines as class C (class B) Barbituates as class C (class B)
Conflict of Interest: