A Meta-Analysis of Research on Motivational Interviewing Treatment

Effectiveness (MARMITE)

Jennifer HettemaJennifer Hettema

Julie SteeleJulie Steele

William R. MillerWilliam R. Miller

Annual Review of Clinical PsychologyAnnual Review of Clinical Psychology

Vol 1, 2005 (in press)Vol 1, 2005 (in press)

funded by a grant from

The Robert Wood Johnson FoundationThe Robert Wood Johnson Foundation

Adoption Curve for InnovationsN

umbe

r of

Ado

ptio

ns

Source: Everett M. Rogers Diffusion of Innovations

Number of MI Publications

050

100150200250300350400450500

83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 0 1 2 3

Years

Num

ber of

Pub

licat

ions

Source: www.motivationalinterview.org/library/biblio.html

MARMITE

MI Outcome Trials

0102030405060708090

100

87 88 89 90 91 92 93 94 95 96 97 98 99 0 1 2 3 4

Years

Num

ber of

Stu

dies

Source: www.motivationalinterview.org/library/biblio.html

MARMITE

Inclusion Criteria for MI Trials

For within-group effect sizes:For within-group effect sizes: At least one treatment group including MIAt least one treatment group including MI At least one post-treatment outcome measureAt least one post-treatment outcome measure

For between-group effect sizes:For between-group effect sizes: At least one control or comparison condition At least one control or comparison condition

without MI componentswithout MI components Procedure for creating pre-treatment Procedure for creating pre-treatment

equivalence of groupsequivalence of groupsMARMITE

All studies double-coded for:

Methodological quality on 12 dimensionsMethodological quality on 12 dimensions Other study characteristicsOther study characteristics Attributes of the MI intervention(s)Attributes of the MI intervention(s) Within-group effect sizesWithin-group effect sizes Between-group effect sizesBetween-group effect sizes

MARMITE

Effect sizes were computed:

For all reported outcome variablesFor all reported outcome variables At all reported follow-up pointsAt all reported follow-up points For all between-group contrastsFor all between-group contrasts With 95% confidence intervalsWith 95% confidence intervals Correcting for small sample biasCorrecting for small sample bias

MARMITE

72 studies included so far:

Alcohol (31)Alcohol (31) One study each: One study each: Drug Abuse (14)Drug Abuse (14) GamblingGambling Smoking (6)Smoking (6) Eating DisordersEating Disorders HIV Risk (5)HIV Risk (5) RelationshipsRelationships Treatment Compliance (5)Treatment Compliance (5) Water purification (4)Water purification (4) Diet and exercise (4)Diet and exercise (4)

MARMITE

Types of Comparisons

MI vs. Specified Treatment (25)MI vs. Specified Treatment (25) MI vs. Treatment as Usual (6)MI vs. Treatment as Usual (6) MI vs No Treatment / Placebo (21)MI vs No Treatment / Placebo (21) MI added to Specified Treatment (7)MI added to Specified Treatment (7) MI added to Treatment as Usual (5)MI added to Treatment as Usual (5) Mixed Designs (6)Mixed Designs (6) Within-Group Only (2)Within-Group Only (2)

MARMITE

Methodological Quality

Compared to 361 alcohol treatment trials:Compared to 361 alcohol treatment trials: MQS Mean = 10.76 vs. 10.68 (ns)MQS Mean = 10.76 vs. 10.68 (ns) Intervention quality controlIntervention quality control 78% vs 57%78% vs 57% Multisite trials:Multisite trials: 28% vs. 5%28% vs. 5% Follow-up Follow-up >> 12 months 12 months 18% vs. 51%18% vs. 51% Follow-up completion Follow-up completion >> 70% 70% 45% vs. 75%45% vs. 75%

MARMITE

Outcome (Dependent) Measures

Mean of 3.3 outcome variables per studyMean of 3.3 outcome variables per study Range: 1 to 12Range: 1 to 12

To avoid capitalization on change, we To avoid capitalization on change, we computed a combined effect size (computed a combined effect size (dd) ) averaging across all reported outcome averaging across all reported outcome variables in each studyvariables in each study

MARMITE

Specified Characteristics of MI

Being collaborativeBeing collaborative Client centeredClient centered NonjudgmentalNonjudgmental Building trustBuilding trust Reducing resistanceReducing resistance Increasing readinessIncreasing readiness

Increasing self-efficacyIncreasing self-efficacy Reflective listeningReflective listening Increasing discrepancyIncreasing discrepancy Eliciting change talkEliciting change talk Exploring ambivalenceExploring ambivalence Expressing empathyExpressing empathy

MARMITE

Specified Characteristics of MI

Of 12 possible characteristics of MI,Of 12 possible characteristics of MI,

The average number mentioned was 3.6The average number mentioned was 3.6

Range: 0-12Range: 0-12

MARMITE

Treatment “Dose” of MI

Average “dose” of 2 sessions (2.2 hours)Average “dose” of 2 sessions (2.2 hours)

The contrasts in dose varied from:The contrasts in dose varied from:

Comparison group 25 hours longer than MIComparison group 25 hours longer than MI

to MI 6 hours longer than no-treatmentto MI 6 hours longer than no-treatment

MARMITE

Quality Control of MI

Average training time: 10 hours (N=13)Average training time: 10 hours (N=13)

Manual-guided Manual-guided 74%74% Post-training supervision Post-training supervision 29%29% Fidelity checks Fidelity checks 36%36%

MARMITE

Where was MI tested?

Outpatient clinics (15)Outpatient clinics (15) Inpatient facilities (11)Inpatient facilities (11) Educational settings (6)Educational settings (6) Community organizations (5)Community organizations (5) G.P. offices (5)G.P. offices (5) Prenatal clinics (3)Prenatal clinics (3) Emergency rooms (2)Emergency rooms (2)

Halfway house (2)Halfway house (2) EAPEAP Telephone (3)Telephone (3) In home (1)In home (1) Jail (1)Jail (1) Mixed (7)Mixed (7) Unspecified (8)Unspecified (8)

MARMITE

Who delivered MI?

Paraprofessionals / students (8)Paraprofessionals / students (8) Master’s level (6)Master’s level (6) Psychologists (6)Psychologists (6) Nurses (3)Nurses (3) Physicians (2)Physicians (2) Dietician (1)Dietician (1) Mixed (22)Mixed (22)

MARMITE

Sample Characteristics (N = 14,267)

N = 21 to 952N = 21 to 952 Mean = 198Mean = 198 Males = 54.8% Males = 54.8% Range = 0 to 100%Range = 0 to 100% Mean Age = 34Mean Age = 34 Range = 16 to 62Range = 16 to 62 Ethnic minorities: Ethnic minorities: 43%43% (N = 37)(N = 37)

MARMITE

Some Generalizations

Wide variability in effect size across studies, Wide variability in effect size across studies, within problem areas (e.g., for alcohol problems, within problem areas (e.g., for alcohol problems, dd varies from 0 to 3.0) varies from 0 to 3.0)

Effects of MI appear earlyEffects of MI appear early Effects of MI diminish over time, Effects of MI diminish over time, except in except in

additive studiesadditive studies d = .77 at post-treatmentd = .77 at post-treatment d = .31 at 4-6 monthsd = .31 at 4-6 months d = .30 at 6-12 monthsd = .30 at 6-12 months

MARMITE

Effect Size of MI Over Time

0

0.2

0.4

0.6

0.8

1

1.2

1.4

0-1 >1-3 >3-6 >6-12 >12

All StudiesC1C2C3

MARMITE

ControlledAdditiveComparative

Effect size was not predicted by:

Number of MI attributes mentionedNumber of MI attributes mentioned Methodological quality of study, Methodological quality of study, exceptexcept

Use of a manual to guide MI Use of a manual to guide MI diddid predict effect size: predict effect size: Studies not using a manualStudies not using a manual dd = .65 = .65 Studies using a manualStudies using a manual d = .37d = .37

Demographic characteristics, Demographic characteristics, exceptexcept:: Anglo/Caucasian samplesAnglo/Caucasian samples dd = .39 = .39 Minority samplesMinority samples dd = .79 = .79

MARMITE

Effect size varied with outcome measures

Alcohol:Alcohol: Quantity of drinkingQuantity of drinking dd = .30 = .30 Frequency of drinkingFrequency of drinking dd = .31 = .31 BAC estimatesBAC estimates d d = .22= .22 Negative consequencesNegative consequences dd = .08 = .08HIV Risk:HIV Risk: KnowledgeKnowledge dd = 1.46 = 1.46 Behavioral IntentionsBehavioral Intentions dd = .88 = .88 Sexual risk-takingSexual risk-taking dd = .07 = .07

MARMITE

Mean Combined Effect Size by Problem Area (N=72 Clinical Trials)

0.14

0.04

0.78

0.14

0.26

0.41

0.72

0.42

0.29

0.44

0.3

0.51

0.29

0.51

0.53

0.71

0 0.2 0.4 0.6 0.8 1

Follow-up

3 MonthsHIV RiskDrug AbusePublic HealthGamblingTreatment AdherenceAlcoholDiet/ExerciseSmoking

MARMITE

Conclusions

1. Robust and enduring effects when MI is 1. Robust and enduring effects when MI is added at the beginning of treatmentadded at the beginning of treatment

MI increases treatment retentionMI increases treatment retention MI increases treatment adherenceMI increases treatment adherence MI increases staff-perceived motivationMI increases staff-perceived motivation

MARMITE

Conclusions

2. The effects of motivational interviewing 2. The effects of motivational interviewing emerge relatively quicklyemerge relatively quickly

(This is also true of other treatments)(This is also true of other treatments)

0

0.2

0.4

0.6

0.8

1

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TX

3 M

ON

TH

6 M

ON

TH

9 M

ON

TH

12

MO

NT

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36

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MARMITE

Project MATCH Outcomes

Conclusions

2a. The effects of motivational interviewing 2a. The effects of motivational interviewing emerge relatively quicklyemerge relatively quickly

This may not be true for certain problem This may not be true for certain problem areas or dependent measures where areas or dependent measures where “sleeper” effects occur (e.g., effects of “sleeper” effects occur (e.g., effects of diet and exercise)diet and exercise)

MARMITE

Conclusions

3. The between-group effects of motivational 3. The between-group effects of motivational interviewing tend to diminish over 12 interviewing tend to diminish over 12 monthsmonths

This is also true of other treatmentsThis is also true of other treatments Between-group differences diminish in Between-group differences diminish in

part because control/comparison groups part because control/comparison groups “catch up” over time“catch up” over time

This may not be true of MI’s additive This may not be true of MI’s additive effects with other treatmenteffects with other treatment

MARMITE

Conclusions

4. The effects of MI are highly variable across 4. The effects of MI are highly variable across sites and providerssites and providers

This is also true of other treatments, but This is also true of other treatments, but may be more true with MImay be more true with MI

Provider baseline characteristics do not Provider baseline characteristics do not predict effectiveness with MIpredict effectiveness with MI

Treatment process variables doTreatment process variables do Manuals may not be a good idea Manuals may not be a good idea

MARMITE