Transcript Related Journal Club Presentation

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):957-66.
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).
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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.
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Assessing Validity of an Article
about Therapy
• Are the results valid?
• What are the results?
• How can I apply the results to patient
care?
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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?
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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?
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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).
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Was randomization concealed?
• Yes.
– Randomization lists for each drug category
and country were prepared by the study
coordinating center in Australia using a webbased randomization program.
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Were patients analyzed in the groups
to which they were randomized?
• Yes (intention-to-treat analysis).
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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.
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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.
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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.
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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.
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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%).
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What Are the Results?
• How large was the treatment effect?
• How precise was the estimate of the
treatment effect?
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How large was the treatment effect?
Intention-to-treat analysis—ANOVA total illicit substance involvement scores
n
Baseline Follow-up Mean effect size
score (SD) score (SD) (% decrease)
Interaction effect*, p, power
BI
86
46.8 (19.3) 39.0 (17.6)
16.7%
F=14.9, p<0.001, power=97%
Control
84
43.7 (18.4) 42.7 (20.0)
2.3%
BI
94
29.2 (14.4) 21.8 (13.9)
25.3%
Control
71
24.7 (11.9) 22.6 (11.8)
8.5%
BI
89
34.7 (14.0) 26.5 (13.1)
23.6%
Control
88
34.8 (14.7) 31.2 (13.5)
10.3%
BI
103
34.9 (22.3) 31.1 (19.7)
10.9%
Control
115
39.0 (24.6) 31.3 (18.7)
19.7%
BI
372
36.1 (18.9) 29.5 (17.5)
18.3%
Control
359
36.2 (19.9) 32.2 (17.9)
11.0%
Interaction by
country effect, p
Australia:
Brazil:
F=9.5, p<0.005, power=86%
India:
F=9.4, p<0.005, power=86%
F=6.5, p<0.001
USA:
F=2.5, p=0.11, power=35%
Pooled:
F=7.4, p< 0.01, power=77%
*Interaction
of time and experimental condition in predicting total illicit substance involvement score. BI: brief intervention; SD:
standard deviation.
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How large was the treatment effect? (cont’d)
n
Intention-to-treat analysis—cannabis scores
Baseline Follow-up Mean effect Interaction effect*, p, power
score
score
size
(SD)
(SD)
(% decrease)
Australia:
BI
17
20.2 (5.3) 17.2 (6.1)
Control
14
19.4 (7.6) 19.0 (7.6)
Brazil:
BI
67
13.3 (6.5) 9.3 (8.2)
Control
45
12.0 (6.0) 12.0 (7.1)
India:
BI
54
22.8 (2.0) 18.9 (6.1)
Control
52
22.3 (2.5) 21.8 (4.9)
USA:
BI
74
16.8 (7.7) 15.1 (9.5)
Control
72
16.2 (6.7) 12.3 (7.0)
Pooled:
BI
212 17.5 (7.1) 14.4 (8.9)
Control
183 17.1 (6.8) 15.4 (7.9)
*Interaction of time and experimental condition in
BI: brief intervention; SD: standard deviation.
14.9%
2.1%
F=2.6, p=0.12, power=34%
30.0%
0.0%
F=9.5, p<0.005, power=86%
17.1%
2.2%
F=10.8, p<0.001, power=90%
10.1%
24.1%
F=3.0, p=0.08, power=41%
Interaction by
country effect, p
F=5.9, p<0.001
17.7%
F=4.0, p<0.05, power=52%
9.9%
predicting cannabis-specific substance involvement score.
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How large was the treatment effect? (cont’d)
Intention-to-treat analysis—stimulant scores
n
Baseline
score (SD)
Follow-up
score (SD)
Mean effect
size
(% decrease)
Interaction effect*, p, power
BI
68
16.8 (7.1)
11.9 (7.3)
29.2%
F=8.5, p<0.005, power=83%
Control
70
15.5 (6.8)
13.7 (7.7)
11.6%
BI
27
15.7 (6.9)
6.5 (5.7)
58.6%
Control
26
11.1 (6.0)
7.7 (6.1)
30.6%
BI
23
20.9 (7.9)
16.2 (11.8)
22.5%
Control
33
18.5 (7.6)
13.2 (10.5)
28.6%
BI
118
17.3 (7.4)
11.5 (8.6)
33.5%
Control
129
15.4 (7.2)
12.4 (8.5)
19.5%
Interaction by
country effect, p
Australia:
Brazil:
F=7.0, p<0.01, power=74%
F=2.8, p=0.06
USA:
F=0.08, p=0.8, power=6%
Pooled:
F=9.4, p<0.005, power=86%
Intention-to-treat analysis—opioid scores
India:
BI
35
22.7 (2.6)
13.0 (8.6)
42.7%
Control
36
22.5 (2.2)
18.2 (7.8)
19.1%
F=7.6, p<0.01, power=78%
*Interaction
of time and experimental condition in predicting stimulant- and opioid-specific substance involvement scores.
BI: brief intervention; SD: standard deviation.
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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?
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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 substancerelated problems occur.
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Were all clinically important
outcomes considered?
• No.
− Drug use was indirectly assessed using ASSIST
scores, limiting the clinical relevance and
interpretation.
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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.
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