Substance abuse variable
     
Frequency of the previous month substance abuse (high vs. low)^{b}

.35

.34 **

.36 **

.35 **

.36 **

t(72) = 3.17

t(71) = 3.24

t(70) = 3.34

t(69) = 3.22

t(68) = 3.15

p = 0.002**

p = 0.002**

p = 0.0013**

p = 0.002**

p = 0.002**

Drug treatment variables
     
The number of psychoactive drugs, other than opioid or BZD (high vs. low)^{c}
 
.32

.35

.35

.35 **


t(71) = 3.06

t(70) = 3.15

t(69) = 3.13

t 68) = 2.99


p = 0.003**

p = 0.002**

p = 0.003**

p = 0.004**

BZD treatment (yes vs. no)
  
.10

.10

10

OST drug type (buprenorphine vs. methadone)
   
.03

.03

Duration of OST (long vs. short)^{d}
    
.01

R^{2} (adjusted)

.110

.203

.199

.189

.177

Model (ANOVA)

F(1,72) = 10.02

F(2,71) = 10.28

F(3,70) = 7.06

F(4,69) = 5.24

F(5,68) = 4.14

p = 0.002**

p = 0.0001***

p = 0.0003 ***

p =0.001***

p =0.002 *

Change (ANOVA)^{a}
 
F(1,71) = 9.37
   

p = 0.003 **

p = 0.40

p = 0.79

p = 0.91
