School-based Randomized Trials for Evaluating Problem Behavior Prevention Programs

“Progress and Prospects for Place-based Randomized Trials” Rockefeller Foundation, Bellagio, Nov 11-15, 2002

UIC University of

Illinois at Chicago

Health Research and Policy Centers

School-based Randomized Trials for Evaluating Problem

Behavior Prevention Programs

Brian R. Flay, D.Phil.Health Research and Policy Centers

University of Illinois at Chicago

Prepared for Conference on“Progress and Prospects for Place-based Randomized Trials”

Rockefeller Foundation Study and Conference CenterBellagio, Italy, November 11-15, 2002


UIC University of

Illinois at Chicago


Problem Behaviors of Youth

• Risky behaviors– Substance use and abuse – Violence– Unsafe sex

• Other health-compromising behaviors– Poor eating habits and inadequate physical activity

• Unacceptable and anti-social behavior– Delinquency

• Poor character development• Psychological and mental disturbances• School failure


UIC University of

Illinois at Chicago


Trends in Annual Prevalence of Illicit Drugs 1975-2001

Data from Monitoring The Future, University of Michigan


UIC University of

Illinois at Chicago


Marijuana: Trends in Annual Use and Risk Perception8th, 10th and 12th graders. Monitoring the Future Data


UIC University of

Illinois at Chicago


Cigarettes: Trends in Annual Use and Risk Perception8th, 10th and 12th graders. Monitoring the Future Data


UIC University of

Illinois at Chicago


Violence Among U.S. Youth• On a typical day, 6 or 7 youth are slain in the U.S., mostly inner-

city, minority youth.• Males account for more than 90% of incidents involving those

10-17 years of age.• Handgun homicides committed by young males (15-18) between

1980 and 1995 increased by more than 150%. • Youth are three times more likely than adults to be victims of

violence. • 5% of students reported feeling too unsafe to attend school at

least once in the thirty days preceding the national youth risk behavior survey.

• 20% of high school students reported carrying a weapon (e.G., Gun, knife, or club) at least once in the thirty days preceding the national youth risk behavior survey.

• ~8% reported carrying a gun, and 10% reported having carried a weapon on school property on one or more occasions in those 30 days.

– Factoids from center for the study and prevention of violence, U Colorado, www.Colorado.edu/cspv/factsheets


UIC University of

Illinois at Chicago


Teen Sexual Behavior

• One quarter of high school freshman girls and just over half (52%) of senior girls have had sex.

• Almost a third (27%) of high school freshman boys and almost two-thirds (59%) of senior boys have had sex.

• Nearly 9 of 10 students enrolled in alternative high schools have had sex.

• Only about 1 in 5 young people do not have intercourse while teenagers.

– Factoids from ETR: www.etr.org/recapp/stats


UIC University of

Illinois at Chicago


History of Approaches to Prevention

• Information about consequences– If only they knew (it’s consequences)– Sometimes included fear (e.g., “Reefer Madness”)

• Affective Approaches– Values Clarification– Decision-Making

• Resistance Skills– Just say “No”

• General Social Skills– Botvin’s Life Skills Training– Social-Emotional Learning

• Correction of Normative Beliefs• Change Social Ecologies

– School-wide– Involving Parents/Families– Involving whole communities


UIC University of

Illinois at Chicago


Use of Theory in Interventions

• Persuasive Communications

• Social Inoculation

• Social Learning

• Learning Theories

• Social Ecology Theories

• Theory of Triadic Influence– Integrates many theories from sociology,

psychology, education, etc.


UIC University of

Illinois at Chicago


The Theory of Triadic Influence

Flay & Petraitis, 1994

BEHAVIOR

Decisions/Intentions

& PersonalityBiology

Sense of Self

SocialSkills

SelfDetermin-

ation

SELFEFFICACY

SocialCompetence

DNA

ValuesEvaluations

Environment

ReligionCulture

ATTITUDES

InformationalEnvironment

CulturalKnowledgeExpectancies

EvaluationsValues

Environment

Bonding

PerceivedNorms

Motivationto Comply

Others'Beh&&Atts

SOCIALNORMATIVEBELIEFSContext

Social


UIC University of

Illinois at Chicago



UIC University of

Illinois at Chicago


Phases of Research in Intervention Development

• Basic Research & Hypothesis Development• Component Development and Pilot Studies• Prototype Studies of Complete Programs• Efficacy Trials of Refined Programs

– Well controlled randomized trials

• Treatment Effectiveness Trials– Generalizability of effects under standardized delivery

• Implementation Effectiveness Trials– Effectiveness with real-world variations in

implementation

• Demonstration Studies– Implementation and evaluation in multiple whole

systems


UIC University of

Illinois at Chicago


Limited Use of Phases

• Few researchers have followed the phases sequence systematically– Botvin comes closest

• Different research skills and interests are needed at the different phases

• Higher stages are often too costly for standard research grant funding

• Holder and colleagues suggested modifications to incorporate interventions developed outside the research environment


UIC University of

Illinois at Chicago


Why Random Assignment of Schools

• Intervention is delivered to intact classrooms• Random assignment of classes is subject to

contamination across classes within schools• Some programs include school-wide

components• Credible causal statements require group

equivalence at both the group and individual levels– On the outcome variable– On presumed mediating variables– On motivation or desire to change


UIC University of

Illinois at Chicago


Randomized Prevention Research Studies

• First Waterloo Study was the first with a sufficient N of schools for randomization to be “real”– Some earlier studies were claimed as “randomized” with only

one or two schools per condition

• Other smoking prevention studies in early-mid 80’s– McAlister, Hansen/Evans, Murray/Luepker, Perry/Murray,

Biglan/Ary, Dielman

• Other substance abuse prevention studies in late 80’s and 90’s– Johnson/Hansen/Flay/Pentz, Botvin and colleagues

• Extended to sexual behavior, AIDs, & Violence in 90’s– Also McArthur Network initiated trials of Comer

• Character Education in 2002– New DoE funding


UIC University of

Illinois at Chicago


Issues re Randomization

• Ethical resistance to the idea of randomization is rare

• Control schools like to have a program too– Use usual Health Education (treatment as usual)– Offer special, but unrelated, program

• E.g., Aban Aya Health Enhancement Curriculum as control for Social Development (violence, sex, drug prevention) Curriculum

– Pay schools for access to collect data from students, parents and teachers -- $500-$2,000 per year

• Currently, many schools are too busy to be in intervention condition– Too many teaching and testing demands– Too many other special programs already


UIC University of

Illinois at Chicago


Approaches to Randomization

• Pure randomization from a large population• Obtain agreement first

– Even prior agreements can break down (Waterloo)

• Then randomize from matched sets defined by– Presumed predictors of the outcome (Graham et al., Aban Aya)– Actual predictors of the outcome (Hawaii Positive Action trial)– Pretest levels of the outcome (has anyone ever achieved this?)

• If schools refuse or drop out, replace from the same set– Only one school of 15 initial selections/assignments for Aban

Aya refused and was replaced

• Or if there are no more cases in the set, drop the set (and watch out for representativeness)– We had to drop multiple sets in the Hawaii Positive Action trial

because of refusal by schools assigned to the program


UIC University of

Illinois at Chicago


Ethnic distribution of students in P, C & all Hawaii Elem. Schools

(PA Trial)

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

40.00

Ethnic Group

Per

cen

t

Program Schools

Control Schools

All of Hawaii


UIC University of

Illinois at Chicago


Characteristics of P and C schools (Hawaii PA Trial)

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ol/1

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/day

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%

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owA

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ove

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es%

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cplu

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eral

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p. R

's p

er10

stu

dent

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SAT Read: % SAT Math: %

School Demographics Achievement Behavior

Program Schools

Control Schools


UIC University of

Illinois at Chicago


Expense --> Small Ns?

• Yes, in many cases– Average efficacy trial (where research funds support

the intervention) has 4-8 schools per condition, and costs ~$500,000 per year.

– Effectiveness trials (where intervention is less costly) have 10-20 schools per condition for $500,000 per year.

• Limit costs by using more small schools– Raises questions about generalizability of results to

large schools

• Limit costs by limiting variability between schools– Also limits generalizability of results


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Illinois at Chicago


The Nature of Control Groups

• Medical model suggests use of a placebo and double blinding, neither of which is possible for educational programs

• Subjects (both students and schools) should have equal expectations of what they will get from the program

• Few studies have used alternative programs to control for Hawthorne effect or student expectancies– TVSFP, Sussman, Aban Aya

• It is not possible to have pure controls in schools today – they all have multiple programs– Must monitor what other programs both sets of schools

have


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Illinois at Chicago


Implications of no blinding• Requires careful monitoring of program delivery• Assessment of acceptance of, involvement in, and

expectations of program by target audience• Monitoring of what happens in control schools• Data collectors blinded to conditions

– Or at least to comparisons being made– This condition has rarely been met in prevention research

• Data collectors not known to students– To ensure greater confidentiality and more honest reports of

behavior

• Classroom teachers should not be present (or be unobtrusive) during student surveys

• Use unobtrusive measures -- rarely used so far– Use of archival data and playground observations are

possibilities– Though they have their own problems


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Illinois at Chicago


Breakdown of Randomization/Design

• Failure of randomization– Don’t use posttest-only designs (to my knowledge none have)

• Schools drop out during course of study– Use signed agreements (none dropped out of Aban Aya)

• Configuration of schools is changed during course of study– E.g., A school is closed, two schools are combined– Drop the paired school as well (& add replacement set if it’s soon

enough)

• A program school refuses to deliver the program, or delivers it poorly– E.g., Schaps Child Development Study only had 5 schools of 12

implement the program well – and reports emphasize results from these 5.

– Botvin often reported results only for students who received more than 60% of the lessons

– “Intention to Treat” analysis should be reported first. Reporting results for the high-implementation group is appropriate only as a secondary level of analysis


UIC University of

Illinois at Chicago


Parental Consent Issues• Historical use of “passive” consent

– Parents informed, but only respond if want to “opt out” their child or themselves

• Some IRBs require active signed consent• When is active consent required?

– If asking “sensitive” questions• Drug use, sexual behavior, illegal behavior, family relationships

– If students “required” to participate• Protection of Pupil Rights Act (PPRA)

– Data are not anonymous (or totally confidential)– There is more than minimal risk if data become non-confidential

• Thus, passive consent should be allowed if:– Not asking about sensitive issues

• Allows surveys of young students (K-3/4)

– Students not required to participate• By NIH rules, students already must be given the opportunity to opt out of complete

surveys or to skip questions• Requires careful “assent” procedures

– Strict non-disclosure protocols are followed• Multiple levels of ID numbers for tracking• No individual (or classroom or school) – level data released


UIC University of

Illinois at Chicago


Changes in Student Body During a Study

• Transfers out and in– Students who transfer out of or into a study school are, on

average, at higher risk than other students– Are transfers out replaced by transfers in, or are rates

different– Are rates the same across experimental conditions?

• Absenteeism– Students with higher rates of absenteeism are also, on

average, at higher risk than others– Are rates the same across experimental conditions?

• Rates of transfers in/out, absenteeism, or dropout that are differential by condition present the most serious problem– Requires careful assessment and analysis– Missing data techniques of limited value when rates are

differential because not MCAR– But may be useful for MAR (that is, if missing is predictable)


UIC University of

Illinois at Chicago


Complex Outcomes, Intensive Measurement and Long-term

Follow-up• Many expected outcomes and mediators leads

to extensive and intensive measurement• Early concern with measurement reactivity

– Led to recommendation of complex designs to rule it out– No longer considered very seriously --– “If only behavior were so easily changed!”

• Long-term follow-up imperative– Few programs with documented effects into or through

high school

• The longer the study, the more the attrition– Due to drop-outs, transfers, absenteeism, refusals


UIC University of

Illinois at Chicago


The Nature of the Target Population

• Universal, Selective and Indicated Interventions– Universal = complete population– Selective = those at higher risk– Indicated = those already evidencing early stages

• Implications of variation in risk levels of students in universal interventions– Suggests multi-level/nested interventions might be

desirableE.g., Fast Track

– Suggests analyses by risk level


UIC University of

Illinois at Chicago


Hypothetical example of differential effects by risk

level

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5

6

T1 T2 T3 T4 T5

Time of measurement

Lev

el o

f b

ehav

ior

Hi Risk Program

Hi Risk Control

Med Risk Program

Med Risk Control

Lo Risk Program

Lo Risk Control


UIC University of

Illinois at Chicago


Unit of Analysis• Has received the most persistent attention• Early studies were analyzed at the student

level• Early recommendation was to analyze at the

school level – the level of random assignment• Much attention to intraclass correlation

– Typically only in the .01-.05 range– With 4-10 schools per condition, analyses at the student and

school level can produce same p values

• Development of multi-level analysis techniques– Bryke & Raudenbush, Goldstein, Hedeker & Gibbons– Longitudinal data seen as another level of nesting– Growth curve analyses becoming popular


UIC University of

Illinois at Chicago


Male violence growth curves by condition (Aban Aya 4 schools per

condition)

0

1

2

3

4

5

5 6 7 8Grade

Cha

nge

in v

iole

nce

HEC SDC S/C


UIC University of

Illinois at Chicago


Male violence was brought down to the level of female

violence

8

9

10

11

12

13

14

15

0 0.5 1 1.5 2 2.5 3 3.5

Males C Males Tx All Females


UIC University of

Illinois at Chicago


Male provoking behavior growth curves (Aban Aya)

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1

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3

4

5

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6 7 8

Grade

Cha

nge

in p

rovo

king

beh

avio

r

HEC SDC S/C


UIC University of

Illinois at Chicago


Male substance use growth curves (logit) (Aban Aya)

0

1

2

3

5 6 7 8Grade

Ch

ang

e in

log

it o

f su

bst

ance

use

HEC SDC S/C


UIC University of

Illinois at Chicago


Male delinquency behavior growth curves (Aban Aya)

0

0.5

1

1.5

2

2.5

3

5 6 7 8Grade

HEC SDC S/C


UIC University of

Illinois at Chicago


Male odds of sexual intercourse by condition

(Aban Aya)

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0.5

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1.5

2

6 7 8

Grade

Ch

ang

e in

log

od

ds

of

sexu

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terc

ou

rse

HEC SDC S/C


UIC University of

Illinois at Chicago


Male condom use by condition (logit ) (Aban Aya)

0.0

0.5

1.0

1.5

2.0

6 7 8

Grade

Cha

nge

in lo

git o

f con

dom

use

HEC SDC S/C


UIC University of

Illinois at Chicago


Complex Interventions

• Always thought of as curricula, or whole programs, not separate components– Few field-based tests of efficacy of separate components to date– But curricula/programs based on basic and hypothesis-driven

research

• Programs have grown more complex over the years• Multiple outcomes are the norm

– Multiple behaviors + Character + Achievement

• Also multiple ecologies are involved– School-wide– Involvement of parents/families– Involvement of community (e.g., Aban Aya)

• Therefore, multiple mediators, both distal and proximal– Distal: Family patterns, school climate, community involvement– Proximal: Attitudes, normative beliefs, self-efficacy, intentions


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Illinois at Chicago


Examples

• Example of major moderation from Aban Aya– Effects for males only

• Examples of mediation from Aban Aya– Following slides

• Example of another kind of process analysis– Later slide from Positive Action

• Example of another kind of moderation– Later slide from Positive Action


UIC University of

Illinois at Chicago


Attitudes toward violence(Aban Aya males)

0.8

1

1.2

1.4

0 0.5 1.5 2.5 3.25

Control Treatment


UIC University of

Illinois at Chicago


Friends’ encouragement of violence (Aban Aya males)

1.2

1.4

1.6

1.8

2

0 0.5 1.5 2.5 3.25

Control Treatment


UIC University of

Illinois at Chicago


Summary of Mediation Results for Males (Aban Aya)

SDC & SCEstimate

Sub. Use

Attitudes

Frnd Bhv.

Encourage

SDC & SC

Attitudes

Violence

Intentions

Estimate

Frnd Bhv.

SDC Condom Use

Mediation analyses not yet done


UIC University of

Illinois at Chicago


Another kind of process analysisEFFECTS OF THE POSITIVE ACTION PROGRAM

Multi-group analysis, School-level data for 55 PA schools and 29 control schools. First path parameter (Standardized) is for Controls, second is for PA schools.

Average % or means shown for all variables. Percentage of variance explained (R2) shown for outcomes.

% African- American (25.2)

% Mobility (43.7)

% Free/reducedlunch (59.6)

% White (51.7)

VIOLENCE: Incidentsper 100 students (3).

R2 .35/.13

Out of SchoolSUSPENSIONS (1.7).

R2 .73/.51

% ABSENT>20 days (3.5).

R2 .64/.61

ACHIEVEMENTR2 .92/.81

FloridaComprehensiveAptitude (Total)(330)

Grade 5 NRT (Total) (319)

1.00

.59/.36

.43/.24

.54/.44

.34/.25

.30/.41 .99

-.30/.-.67

-.53/-.14

Model Fit: 2 = 48.03

@ 40 dfp=.18

RMSEA .069

Constrained model fit: 2 = 69.4 @ 51 df

p=.09, RMSEA=.09.

2 diff = 21.37 @ 11 df, p=.03.

.26

.70

-.73

-.36

.63

-.76

.53/.59

.00/.32


UIC University of

Illinois at Chicago


Another example of moderation

Effects are larger where they are most needed

0

5

10

15

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25

30

>15% 10-15% < 10%

% Free/Reduced Lunch

Mean

# I

ncid

en

ts

No PA

PA


UIC University of

Illinois at Chicago


Remaining Limitations of Most Prevention Programs

Today• Domain Specific

– Usually only one behavior or one skill

• Start too late – Upper elementary or middle school

• Limited intensity and dose– Often only once a week for 10-20 sessions

• Ecologically Limited– Usually only classroom– Also need school-wide, parent, community

• Limited Effect Sizes– Average effect sizes in the 0.2 to 0.4 range

• Effects not Sustained– Few effects beyond one year, let alone end of

H. S.


UIC University of

Illinois at Chicago


School-based Prevention/Promotion Research

Needs More…• Larger randomized trials

– With more schools per condition

• Comparisons with “treatment as usual”• Measurement of implementation process and

program integrity• Assessment of effects on presumed mediators

– Helps test theories

• Multiple measures/sources of data– Surveys of students, parents, teachers, staff, community– Teacher and parent reports of behavior– School records for behavior and achievement

• Multiple, independent trials of promising programs– At both efficacy and effectiveness levels

• Cost-effectiveness analyses

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School-based Randomized Trials for Evaluating Problem Behavior Prevention Programs

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