Table 3.

Changes in drug use from baseline to follow-up, n = 33

Drug category	Baseline mean	Follow-up mean	Mean difference	t-test, P value	95% CI
Heroin	2.97	0.035	2.936	0.000	2.178 to 3.695
Opiates	0.917	0.001	0.918	0.034	0.074 to 1.762
Alcohol	1.138	3.012	−1.421	0.217	−3.72 to 0.878
Cannabis	0.893	0.704	0.247	0.497	−0.486 to 0.979
Amphetamine	0.005	0.022	−0.017	0.465	−0.064 to 0.030
Cocaine	0.344	0.023	0.320	0.317	−0.321 to 0.961
Crack cocaine	0.037	0.157	−0.126	0.190	−0.317 to 0.065
Tranquillisers	1.933	0.096	1.833	0.017	0.356 to 3.309
Tobacco	15.267	12.364	2.984	0.045	0.071 to 5.897
Polydrug	3.996	2.364	1.656	0.000	1.018 to 2.295
Illicit polydrug	2.701	0.940	1.700	0.000	1.144 to 2.256