# Abstract

 # Results 

## Sample demographics Participants (n = 190) were recruited from 40 states and all were licensed or certified to conduct substance abuse treatment. Certified drug and alcohol providers comprised 33% of the sample, 31% were social workers, and were 18% Licensed Professional Counselors, with the remaining 18% in various other disciplines such as psychologists, physicians and nurses. Participants reported that they spent, on average, 25.62 (SD = 11.16) h per week treating clients with substance use disorders. Women comprised 62% of the sample. Participants were 79.7% White, 5.9% Black or African American, 2.6% American Indian/Alaska Native, 0.7% Asian or Asian American, 5.9% Hispanic, 5.2% other backgrounds (See [Table 2](#) ). All participants were fluent in spoken and written English. The two groups were examined for differences in relevant baseline measures. Groups were equivalent with regard to all examined characteristics including gender, ethnicity, education, and experience. At baseline, there were no differences between groups on measures of clinician speech (e.g., MICO, reflection:question ratio, percent complex reflections; all p > 0.38) or client speech (change talk, sustain talk, percent CT; all p > 0.42). 

## Participant attrition and follow up A total of 776 work samples were collected across all follow-up points. To ensure that the data reflected the effects of training enrichments, samples from participants who completed fewer than three consult calls were excluded. Samples that did not adhere to study criteria (i.e., role-played sessions, non-SUD target behaviors, more than seven sessions with same client) were similarly excluded, as were inaudible sessions. This resulted in a sample of 609 sessions, or 78.5% of all sessions submitted, with 81.7% at 3 months, 73.2% at 6 months and 51% at 12 months. After each follow-up, participants received global ratings of their MI proficiency based upon their MISC ratings of the submitted sample. There were no between-group differences on the number of work samples submitted at any follow-up (all p > 0.25), nor were there any differences between groups in the number of consult calls completed (t(189) = 0.404, p > 0.60, d = 0.0594). 

## Interrater reliability estimates for coding of worksamples A subset of 72 randomly selected recordings (11.8%) were coded by the 6 coders completing the majority (84.7%) of all recordings. Intraclass correlations (ICC's) across all six coders for behavior counts ranged from 0.59 to 0.99 (Cicchetti, 1994). For this reliability sample, 34.7% of the total tapes were drawn from MIU, 65.3% from LEAF, (t(71) = 2.704, p < 0.01), indicating that despite random selection the LEAF condition was oversampled. Since the most challenging behaviors to code (RefCT, RefST) are more frequent in the LEAF condition, this disparity in the sampling may have resulted in an underestimate of the reliability of the coders for the entire sample of tapes. (See [Table 3](#) for all reliability estimates. 

## Analysis plan Because outcome measures were nested within participants, multilevel modeling was used to assess the impact of the experimental manipulation. Our analyses examined client language both 1) at the 3 month follow up and 2) in all follow-up periods simultaneously. Mediation analyses focused on the 3 month follow up period. We used the PROCESS software (Hayes, 2013) to examine the relationship between group assignment and client language, mediated by the directional reflections of the providers (a strategy emphasized in the MI Leaf condition). We expected that group assignment (MI AU v MI Leaf) would predict the type of reflections used by participants in their follow up work samples (A path) and that directional reflections would predict client speech in those sessions (B path). Overall, we expected to see a relationship between group assignment and client speech (C path). 

## Was there a training effect for the MI workshop? 

### Knowledge test The MI Knowledge Test was used as the outcome measure to estimate the impact of training. It was administered at baseline and post-training, and results indicate a significant increase in MI knowledge (b = 0.111, SE = 0.015, t = 7.146, p < 0.001) for all participants with no significant differences between training conditions (b = −0.041, SE = 0.031, t = −1.328, p = 0.186). 

### Frequency counts of outcome variables As expected, common MI skills that were common to both treatment conditions, such as providing complex reflections (b = 0.063, SE = 0.080, p = 0.43, CI[0.910--1.247] and asking open questions (b = −0.087, SE = 0.071, p = 0.221, CI[0.797--1.054], showed no significant differences between training conditions. 

## Was there a difference in participants' reflections of client language in follow up sessions depending on training condition? Collapsing across all time points, the frequency of the participants' reflections of client CT did not differ between groups as hypothesized (b = 0.037, SE = 0.097, p = 0.703, 95% CI [−0.155 to 0.230], d = 0.062). However for reflections of ST, there was a significant difference such that participants in the LEAF-MI group gave fewer reflections of sustain talk than those in the MI-AU training (b = −0.257, SE = 0.114, p = 0.025, CI [−0.032 to 0.481], d = −0.369). 

## Did the language of clients in follow up samples differ depending on training condition of the participants? For the 3 month follow up, the frequency of client CT did not differ significantly in the treatment sessions as a result of training condition, contradicting our hypothesis (b = −0.0857, SE = 0.0923, 95% CI \[0.765, 1.102), T = −0.929, p = 0.355. However, ST was significantly lower for clients of participants trained in the MI-LEAF condition (b = −0.1008, SE = 0.0179, 95% CI \[0.873, 0.937), T = −5.629, p < 0.001) as hypothesized. This pattern was the same, but less robust, when collapsing across all time points. Frequency of client CT did not differ significantly between the training groups, (b = −0.018, SE = 0.064, p = 0.781, CI [−0.0145, 0.110], T = −0.279, p = 0.781 However, ST was significantly lower for the clients of participants trained in the LEAF-MI condition (b = −0.175, SE = 0.087, p = 0.046, CI [−0.347, 0.003], T = −2.01, p = 0.046). 

## Is there evidence for a causal chain implicating specialized training, resulting participant's reflections of client language and the frequencies of client language at the three-month follow-up? A priori mediation analyses focusing on change talk were not significant (K2 = 0.0295, bootstrap SE = 0.0556, 95% CI [0.000, 0.912]). For sustain talk, however, the causal chain for a) training and b) subsequent participant focus on sustain talk in follow up sessions and c) client sustain talk during those same sessions was significant (K2 = 0.0833, bootstrap SE = 0.0394, 95% CI [0.0148, 0.1691]). Specifically, group assignment (C path) predicted client speech in follow up sessions, but this was mediated by the type of reflections used by the provider (B path) such that those who had been trained in the MI Leaf condition offered fewer reflections of sustain talk (A path) (See [Table 4](#) ). Training Component MI AU MI LEAF ------------------------------- ---------------------------------------------------------- ----------------------------------------------------------------------------- **Workshop Content** Language Focus = 5% Language Focus = 40% **Consultations** Standard: all MI Skills Client language sole focus **Feedback from worksamples** Did not include client language information Included counts of client change and sustain talk **Video learning resources** Standard MI DVD format (Miller, Rollnick & Moyers, 1998) Client language DVD made for Elicit Project (Moyers, Miller & Manuel, 2012) ::::table-wrap

::: caption
Demographic characteristics of participant-providers
:::

Characteristic M SD

______________________________________________________________________

Age (years) 45.2 10.4
Years Prior Clinical Experience\
In Mental Health 12.4 8.4
In Substance Abuse 9.7 7.9
Clinical Hours Per Week\
Treating Clients 25.9 11.7
Treating Substance Abuse Clients 22.5 11.4
Prior Hours Spent Learning MI 8.1 10.5
**N** **%**
Gender\
Female 96 62.7%
Male 57 37.3%
Race\
American Indian or Alaska Native 4 2.6%
Asian or Asian American 1 0.7%
Black or African American 9 5.9%
White, not of Hispanic origin 122 80.4%
White, Hispanic origin 9 3.9%
Other 8 5.2%:::: ::::table-wrap
::: caption
Estimates of inter-rater reliability for the MISC 2.5 Codes
:::

Summary variable ICC 95% CI *f* M (SD)

______________________________________________________________________

CT 0.93 0.90 0.95 19021 31.23 (20.86)
ST 0.90 0.86 0.93 7748 12.72 (12.29)
Follow/Neutral/Ask 0.93 0.88 0.96 45498 74.71 (41.41)
MICO 0.94 0.92 0.96 35055 57.56 (26.73)
MIIN 0.59 0.49 0.68 1573 2.58 (4.14)
Question 0.99 0.98 0.99 25891 42.51 (27.49)
Closed Question 0.97 0.95 0.98 17191 28.23 (21.28)
Open Question 0.89 0.86 0.93 8700 14.29 (10.47)
Reflect 0.95 0.94 0.97 20536 33.72 (19.64)
Reflect CT 0.86 0.82 0.90 5356 8.79 (8.21)
Reflect ST 0.61 0.52 0.71 2289 3.76 (4.84)
Reflect Other 0.87 0.82 0.91 12891 21.17 (14.69)
Simple Reflection 0.74 0.66 0.81 10544 17.31 (13.05)
Complex Reflection 0.75 0.67 0.82 9992 16.41 (11.25)

*Note*. ICC = intraclass correlation; CT = change talk; ST = sustain
talk.

ICC *n* = 72, *k* = 6; *f* and M *n* = 609:::: ::::table-wrap
::: caption
Indirect effect of group assignment on client speech via provider speech
at the 3-month follow-up
:::

a. Change talk

______________________________________________________________________

Variable Coefficient 95% CI SE *t* *p*
*Effect of group assignment on reflections of change talk (a path)*\
Constant 0.265 0.205 0.324 0.030 8.771 .000
Group −0.013 −0.096 0.071 0.042 −0.302 .764
*Effect of reflections of change talk on change talk covarying for group (b path)*\
Constant 0.413 0.308 0.518 0.053 7.780 .000
RefCT 1.628 1.381 1.874 0.125 13.072 .000
Group −0.059 −0.174 0.056 0.058 −1.012 .314
*Total effect of group on change talk (c path)*\
Constant 0.844 0.716 0.971 0.064 13.128 .000
Group −0.080 −0.257 0.098 0.090 −0.886 .377
*Direct effect of group on change talk*\
Group −0.059 −0.174 0.056 0.058 −1.012 .314
*Bootstrapped indirect effect on change talk via reflections of change talk (κ ^2^ )*\
RefCT −0.030 0.000 0.091 0.056 -- --

b. Sustain talk

______________________________________________________________________

Variable Coefficient 95% CI SE *t* *p*
*Effect of group assignment on reflections of sustain talk (a path)*\
Constant 0.110 0.785 0.142 0.016 6.898 .000
Group −0.047 −0.091 −0.002 0.022 −2.089 .039
*Effect of reflections of sustain talk on sustain talk covarying for group (b path)*\
Constant 0.140 0.065 0.215 0.038 3.681 .003
RefST 0.911 0.551 1.271 0.182 5.001 .000
Group 0.037 −0.054 0.127 0.046 0.804 .423
*Total effect of group on sustain talk (c path)*\
Constant 0.240 0.170 0.303 0.035 6.812 .000
Group -.006 −.010 0.092 0.049 −0.114 .909
*Direct effect of group on sustain talk*\
Group 0.368 −0.054 0.127 .046 0.804 .423
*Bootstrapped indirect effect on sustain talk via reflections of sustain talk (κ ^2^ )*\
RefST 0.083 0.015 0.169 0.039 -- --

*Note*. RefCT = reflections of change talk; RefST = reflections of
sustain talk::::


Extracted trial result:
Outcome: Motivational Interviewing (MI) knowledge (continuous)
Intervention: MI training (MI-AU)
Comparator: baseline
Notes: No group sizes and individual means and stds given