Journal Club Alcohol, Other Drugs, and Health: Current Evidence May–June 2012

Featured Article A Randomized Controlled Trial of a Brief Intervention for Illicit Drugs Linked to the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) in Clients Recruited from Primary Health-Care Settings in Four Countries Humeniuk R, et al. Addiction. 2012;107(5):

Study Objective To evaluate the effectiveness of a brief intervention (BI) for illicit drugs (cannabis, cocaine, amphetamine-type stimulants and opioids) linked to the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST).

4 Study Design Prospective randomized controlled trial conducted in primary health-care settings * in Australia, Brazil, India, and the United States. Patients screened with the ASSIST who scored in the moderate-risk range for cannabis, cocaine, amphetamine-type stimulants, or opioids (N=731) were assigned to either waitlist (control group) or to A brief intervention (BI) for the drug receiving the highest score. ASSIST-specific scores for cannabis, stimulants, or opioids as well as ASSIST total illicit substance involvement scores at baseline and 3 months were compared. *Sexually-transmitted disease, dental, primary-care, and other outpatient clinics.

Assessing Validity of an Article about Therapy Are the results valid? What are the results? How can I apply the results to patient care?

Are the Results Valid? Were patients randomized? Was randomization concealed? Were patients analyzed in the groups to which they were randomized? Were patients in the treatment and control groups similar with respect to known prognostic variables?

Are the Results Valid? (cont‘d) Were patients aware of group allocation? Were clinicians aware of group allocation? Were outcome assessors aware of group allocation? Was follow-up complete?

Were patients randomized? Yes. –Patients were randomized to BI or waitlist immediately following the baseline interview. –Randomization was stratified by gender, substance, and level of use (high/low).

Was randomization concealed? Yes. –Randomization lists for each drug category and country were prepared by the study coordinating center in Australia using a web- based randomization program.

Were patients analyzed in the groups to which they were randomized? Yes (intention-to-treat analysis).

Were the patients in the treatment and control groups similar? Unknown. –A demographic profile questionnaire was administered at baseline, however, demographic data broken down by group assignment was not provided. –More than two-thirds of the total sample were men; the mean age was 31.4 years (SD=9.3), and the average years of education was 9.5 (SD=5.2). Just over half had never been married, and roughly one-third were either married or cohabiting. Most identified themselves as Caucasian (59.6%), followed by Indian (24.4%) or African (7.3%). Fifteen per cent (15%) of participants had received previous treatment for drug or alcohol problems. –Groups did not differ significantly at baseline with respect to their total illicit substance involvement scores or specific substance involvement scores.

Were patients aware of group allocation? Yes. –It was not possible to blind the patients as to whether they were receiving the BI or not.

Were clinicians aware of group allocation? Yes. –Clinical research staff were not blind to group allocation as they were responsible for administering the intervention at baseline.

Were outcome assessors aware of group allocation? Yes. –In the majority of cases, the same clinical researcher performed both the baseline and follow-up interviews.

Was follow-up complete? Forty-nine of 372 participants in the intervention group were lost to follow-up (13%) compared with 51 of 359 participants in the control group (14%).

What Are the Results? How large was the treatment effect? How precise was the estimate of the treatment effect?

How large was the treatment effect? Intention-to-treat analysis—ANOVA total illicit substance involvement scores nBaseline score (SD) Follow-up score (SD) Mean effect size (% decrease) Interaction effect *, p, powerInteraction by country effect, p Australia: F=6.5, p<0.001 BI (19.3)39.0 (17.6)16.7%F=14.9, p<0.001, power=97% Control (18.4)42.7 (20.0)2.3% Brazil: BI (14.4)21.8 (13.9)25.3%F=9.5, p<0.005, power=86% Control (11.9)22.6 (11.8)8.5% India: BI (14.0)26.5 (13.1)23.6%F=9.4, p<0.005, power=86% Control (14.7)31.2 (13.5)10.3% USA: BI (22.3)31.1 (19.7)10.9%F=2.5, p=0.11, power=35% Control (24.6)31.3 (18.7)19.7% Pooled: BI (18.9)29.5 (17.5)18.3%F=7.4, p< 0.01, power=77% Control (19.9)32.2 (17.9)11.0% * Interaction of time and experimental condition in predicting total illicit substance involvement score. BI: brief intervention; SD: standard deviation.

How large was the treatment effect? (cont’d) Intention-to-treat analysis—cannabis scores n Baseline score (SD) Follow-up score (SD) Mean effect size (% decrease) Interaction effect *, p, powerInteraction by country effect, p Australia: F=5.9, p<0.001 BI (5.3)17.2 (6.1)14.9%F=2.6, p=0.12, power=34% Control (7.6)19.0 (7.6)2.1% Brazil: BI (6.5)9.3 (8.2)30.0%F=9.5, p<0.005, power=86% Control (6.0)12.0 (7.1)0.0% India: BI (2.0)18.9 (6.1)17.1%F=10.8, p<0.001, power=90% Control (2.5)21.8 (4.9)2.2% USA: BI (7.7)15.1 (9.5)10.1%F=3.0, p=0.08, power=41% Control (6.7)12.3 (7.0)24.1% Pooled: BI (7.1)14.4 (8.9)17.7%F=4.0, p<0.05, power=52% Control (6.8)15.4 (7.9)9.9% * Interaction of time and experimental condition in predicting cannabis-specific substance involvement score. BI: brief intervention; SD: standard deviation.

How large was the treatment effect? (cont’d) Intention-to-treat analysis—stimulant scores nBaseline score (SD) Follow-up score (SD) Mean effect size (% decrease) Interaction effect *, p, powerInteraction by country effect, p Australia: F=2.8, p=0.06 BI (7.1)11.9 (7.3)29.2%F=8.5, p<0.005, power=83% Control (6.8)13.7 (7.7)11.6% Brazil: BI (6.9)6.5 (5.7)58.6%F=7.0, p<0.01, power=74% Control (6.0)7.7 (6.1)30.6% USA: BI (7.9)16.2 (11.8)22.5%F=0.08, p=0.8, power=6% Control (7.6)13.2 (10.5)28.6% Pooled: BI (7.4)11.5 (8.6)33.5%F=9.4, p<0.005, power=86% Control (7.2)12.4 (8.5)19.5% Intention-to-treat analysis—opioid scores India: BI (2.6)13.0 (8.6)42.7%F=7.6, p<0.01, power=78% Control (2.2)18.2 (7.8)19.1% * Interaction of time and experimental condition in predicting stimulant- and opioid-specific substance involvement scores. BI: brief intervention; SD: standard deviation.

How Can I Apply the Results to Patient Care? Were the study patients similar to the patients in my practice? Were all clinically important outcomes considered? Are the likely treatment benefits worth the potential harm and costs?

Were the study patients similar to those in my practice? Participants were adult men and women from 4 countries. The majority were not from the United States. Diverse study sites were selected to represent a broad range of cultural, political and economic systems in which substance- related problems occur.

Were all clinically important outcomes considered? No. −Drug use was indirectly assessed using ASSIST scores, limiting the clinical relevance and interpretation.

Are the likely treatment benefits worth the potential harm and costs? No harms or costs were presented. The benefits were modest, of questionable clinical relevance, likely biased due to lack of blinding, and not statistically significant in the US sample. Additional research is needed prior to widespread dissemination.