Table 2.

Spearman correlations between key dependent and independent variables.

	Spearman correlation coefficients
Variables	(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)	(11)
(1) Overall drug use improvement	1.000	0.782c	0.054b	0.040a	0.693c	0.043a	0.053b	0.028	−0.228c	0.042a	0.187c
(2) Primary drug use improvement		1.000	0.045a	0.062c	0.534c	0.078c	0.074c	0.075c	−0.232c	0.015	0.181c
(3) Percent of needs service matched			1.000	0.176c	−0.030	0.086c	0.056b	−0.115c	−0.053b	−0.033	0.166c
(4) Treatment duration, per week				1.000	−0.048b	−0.033	−0.024	0.264c	0.184c	−0.531c	0.055b
(5) Past-year peak level of drug use					1.000	−0.047b	0.020	0.254c	−0.360c	0.060c	0.149c
(6) Reduction from past-year peak use						1.000	0.018	−0.307c	0.131c	0.053b	0.038a
(7) Female gender							1.000	−0.019	−0.113c	−0.016	0.148c
(8) Methadone modality								1.000	d	d	d
(9) Non-methadone out-patient modality									1.000	d	d
(10) Short-term residential modality										1.000	d
(11) Long-term residential modality											1.000

^aP < 0.05;

^bP < 0.01;

^cP < 0.001;

^ddummy variable, correlations not meaningful.