Table 4.
Main Results: Effects on Days Using the Main Drug by Primary Care Patients With Unhealthy Drug Use Identified by Screening of Brief Interventions
| Predicted Meana No. of Days Using Main Drugb
in Past 30 Days at 6 Monthsc |
BNI vs Control |
MOTIV vs Control |
||||||
|---|---|---|---|---|---|---|---|---|
| No. | BNI | MOTIV | Control | IRR (95% CI) | P Valued | IRR (95% CI) | P Valued | |
| Overall analysise | ||||||||
|
| ||||||||
| Unadjusted | 517 | 14.2 | 14.1 | 13.8 | 1.03 (0.80-1.34) | .85 | 1.03 (0.79-1.33) | .85 |
|
| ||||||||
| Adjustedf | 516 | 11.2 | 12.1 | 11.5 | 0.97 (0.77-1.22) | .81 | 1.05 (0.84-1.32) | .81 |
|
| ||||||||
| Stratified by Main Drug b | ||||||||
|
| ||||||||
| Opioids | ||||||||
|
| ||||||||
| Unadjusted | 88 | 7.0 | 8.0 | 8.8 | 0.80 (0.33-1.92) | .84 | 0.91 (0.38-2.21) | .84 |
|
| ||||||||
| Adjustedg | 88 | 6.4 | 7.4 | 7.6 | 0.85 (0.35-2.07) | .96 | 0.98 (0.41-2.34) | .96 |
|
| ||||||||
| Cocaine | ||||||||
|
| ||||||||
| Unadjusted | 97 | 8.0 | 7.4 | 5.3 | 1.51 (0.78-2.91) | .31 | 1.41 (0.73-2.72) | .31 |
|
| ||||||||
| Adjustedg | 97 | 5.7 | 7.2 | 5.0 | 1.15 (0.62-2.14) | .66 | 1.44 (0.78-2.65) | .48 |
|
| ||||||||
| Marijuana | ||||||||
|
| ||||||||
| Unadjusted | 323 | 18.3 | 18.2 | 18.0 | 1.02 (0.80-1.31) | .91 | 1.01 (0.79-1.30) | .91 |
|
| ||||||||
| Adjustedg | 322 | 16.7 | 17.1 | 16.7 | 1.00 (0.80-1.25) | .99 | 1.02 (0.82-1.28) | .99 |
|
| ||||||||
| Stratified by ASSIST Score h | ||||||||
|
| ||||||||
| ASSIST<27 | ||||||||
|
| ||||||||
| Unadjusted | 424 | 14.3 | 14.3 | 14.2 | 1.01 (0.76-1.33) | .96 | 1.01 (0.76-1.33) | .96 |
|
| ||||||||
| Adjustedf | 423 | 11.1 | 11.7 | 11.5 | 0.97 (0.76-1.23) | .86 | 1.02 (0.80-1.30) | .86 |
|
| ||||||||
| ASSIST≥27 | ||||||||
|
| ||||||||
| Unadjusted | 93 | 13.5 | 13.1 | 12.2 | 1.11 (0.55-2.23) | .84 | 1.07 (0.54-2.12) | .84 |
|
| ||||||||
| Adjustedf | 93 | 10.7 | 12.6 | 10.6 | 1.01 (0.52-1.98) | .97 | 1.19 (0.63-2.26) | .97 |
Abbreviations: ASSIST, Alcohol, Smoking and Substance Involvement Screening Test; BNI, brief negotiated interview; CIDI-SF, Composite International Diagnostic Interview Short Form; MOTIV, adaptation of motivational interviewing; IRR, incidence rate ratio.
Model-based expected counts from negative binomial regression models calculated for population with observed means and proportions of the overall sample.
“Main drug” was drug of most concern, as determined by the participant.
As measured by Timeline Followback method.14
Adjusted for multiple comparisons using the Hochberg procedure.
The results of the multiple imputation analysis were similar to the overall main analysis, adjusted IRR, 0.98 (95%CI, 0.79-1.23) for BNI, and adjusted IRR, 1.05 (95%CI, 0.84-1.31) for MOTIV. Variables used for imputation were age, sex, and the variables in the primary analysis.
Model adjusted for the following baseline covariates: drug of most concern (main drug), number of days main drug used in past 30 days, CIDI-SF drug dependence, and outpatient treatment during past 3 months for addiction or mental health. Results were similar in analyses that did not adjust for outpatient visits.
Model adjusted for the following baseline covariates: number of days main drug used in past 30 days, CIDI-SF drug dependence, and outpatient treatment during past 3 months for addiction or mental health.
Ranges from 0-39; higher score means riskier use.