Table 2.

Reliability of cannabis screening instruments

Scale	Study	Internal consistency	Test-retest reliability	Item total correlation
General population samples
SDS	Steiner et al. (2008)	.80
SDS	Martin et al. (2006)	.83	.88 (total), .69 to .85 (items)
CAST	Legleye et al. (2007)	.81 [.74 for cannabis users]		.26 to .56 (pairs of items)
CUDIT	Annaheim et al. (2008)	.72		.07 to .55
PUM	Okulicz-Kozaryn (2007)	.92
Specific user samples
SDS	Swift, Hall et al. (1998)	.72
SDS	Hides et al. (2007)	.81
SDS	Ferri et al. (2000)	.78	.74 (total), .46 to .76 (items)
CUDIT	Adamson & Sellman (2003)	.78		.44 to .77