Table 3.
Motivational Interview Length, Adherence and Competence Scores, and Percent Change Talk
| Workshop (N = 3) | Apprentice (N = 11) | Consult (N = 100) | Consult versus workshop | Consult versus apprenticeship | ||||
|---|---|---|---|---|---|---|---|---|
| Mean | SD | Mean | SD | Mean | SD | Hedge’s g | Hedge’s g | |
| Interview length (in min) | 10.5* | 6.2 | 16.4† | 8.7 | 24.2*,† | 8.3 | 1.65 | 0.93 |
| Fundamental adherence‡ | 4.0* | 0.4 | 4.6† | 0.8 | 5.2*,† | 0.6 | 2.00 | 0.96 |
| Fundamental competence§ | 3.7* | 0.6 | 4.3† | 0.4 | 4.7*,† | 0.5 | 1.98 | 0.81 |
| Advanced adherence‡ | 3.9 | 0.6 | 4.4 | 1.0 | 4.8 | 0.7 | 1.28 | 0.54 |
| Advanced competence§ | 3.9 | 0.9 | 4.3 | 0.5 | 4.5 | 0.5 | 1.17 | 0.40 |
| Percent change talkǁǁ | 68.9 | 18.3 | 80.9 | 9.8 | 76.6 | 16.4 | 0.47 | − 0.26 |
Inter-rater reliability based on intra-class correlation coefficients (ICC) was good to very good for fundamental and advanced adherence and competence scores (ICCs ranged from 0.71 to 0.85) and excellent for percent change talk (0.96)58
Means that share a superscript (*,†) are significantly different at p < 0.05 based upon results of the Kruskal-Wallis test with the Dwass, Steel, Critchlow-Fligner method for post hoc pairwise comparisons
‡Adherence rated from 1 (not at all) to 7 (extremely)
§Competence rated from 1 (very poor) to 7 (outstanding)
ǁǁPercent change talk > 50% indicates most patient statements in sessions favored reducing primary substance use