The Transtheoretical Model of Health Behavior Change€¦ · The Transtheoretical Model of Health Behavior Change James O. Prochaska, Wayne F. Velicer Abstract The transtheoretical

THE S CIENCE OF HEALTH PROMOTION

Behavior Change

The Transtheoretical Model of Health BehaviorChangeJames O. Prochaska, Wayne F. Velicer

Abstract

The transtheoretical model posits that health behavior change involves progress throughsix stages of change: precontemplation, contemplation, preparation, action, maintenance,and termination. Ten processes of change have been identified for producing progress alongwith decisional balance, self-efficacy, and temptations. Basic research has generated a ruleof thumb for at-risk populations: 40 % in precontemplation, 40 % in contemplation, and20% in preparation. Across 12 health behaviors, consistent patterns have been found be-tween the pros and cons of changing and the stages of change. Applied research has dem-onstrated dramatic improvements in recruitment, retention, and progress using stage-matched interventions and proactive recruitment procedures. The most promising outcomesto date have been found with computer-based individualized and interactive interventions.The most promising enhancement to the computer-based programs are personalized counsel-ors. One of the most striking results to date for stage-matched programs is the similaritybetween participants reactively recruited who reached us for help and those proactively re-cruited who we reached out to help. If results with stage-matched interventions continue tobe replicated, health promotion programs will be able to produce unprecedented impacts onentire at-risk populations. (Am J Health Promot 1997;1211]:38-48.)

Key Words: Transtheoretical Model, Stages of Change, Proactive Recruitment,Computerized Interventions, Decisional Balance, Processes of Change

James o. Prochaska, PhD, and Wayne F. Velic~ PhD, are at the Cancer Prevention ResearchCent~ University of Rhode Island, Kingston, Rhode Island.

Send reprint requests to James o. Prochaska, Cancer Prevention Research Center, 2 Chafee Road,University of Rhode Island, Kingston, RI 02881-0808; [email protected].

This manuscript was submitted April 1, 1997; revisions roere requested April 7, 1997; the manuscript was accepted forpublication May 5, 199Z

Am J Health Promot 1997;12(1):38-48.Copyright © 1997 by American Journal of Health Promotion, Inc.0890-1171/97/$5.00 + 0

The transtheoretical model uses atemporal dimension, the stages ofchange, to integr~.te processes andprinciples of change from differenttheories of intervention, hence thename transtheoretical. This modelemerged from a comparative analysisof leading theories of psychotherapyand behavior change. The goal was asystematic integration of a field thathad fragmented i:ato more than 300theories of psychotherapy.1 The com-parative analysis i,zlentified 10 distinctprocesses of change, such as con-sciousness raising from the Freudiantradition, contingency managementfrom the Skinnerian tradition, andhelping relationships from the Ro-gerian tradition.

In an empiric~.l analysis of self-changers compared to smokers inprofessional treatments, we assessedhow frequently each group used eachof the 10 processes.2 Our researchparticipants kept saying that theyused different processes at differenttimes in their straggles with smoking.These naive subjects were teachingus about a phenomenon that was notincluded in any of the multitude oftherapy theories. They were revealingto us that behavior change unfoldsthrough a series of stages.3

From the initial studies of smok-ing, the stage model rapidly expand-ed in scope to ir.clude investigationsand applications with a broad rangeof health and mental health behav-iors. These include alcohol and sub-stance abuse, anxiety and panic dis-orders, delinquency, eating disordersand obesity, high-fat diets, AIDS pre-vention, mammography screening,medication compliance, unplannedpregnancy prevention, pregnancyand smoking, ration testing, seden-

38 American Journal of Health Promotion

tary lifestyles, sun exposure, and phy-sicians practicing preventive medi-cine. Over time, these studies haveapplied, expanded, validated, andchallenged the core constructs of thetranstheoretical model.

CORE CONSTRUCTS

Stages of ChangeThe stage construct is important

in part because it represents a tem-poral dimension. Change impliesphenomena occurring over time, butsurprisingly, none of the leading the-ories of therapy contained a coreconstruct representing time. Behav-ior change was often construed as anevent, such as quitting smoking,drinking, or overeating. The trans-theoretical model construes changeas a process involving progressthrough a series of six stages.

Precontemplation is the stage inwhich people are not intending totake action in the foreseeable future,usually measured as the next 6months. People may be in this stagebecause they are uninformed or un-derinformed about the consequencesof their behavior. Or they may havetried to change a number of timesand become demoralized about theirabilities to change. Both groups tendto avoid reading, talking, or thinkingabout their high risk behaviors. Theyare often characterized in other the-ories as resistant or unmotivated cli-ents or as not ready for therapy orhealth promotion programs. The factis, traditional health promotion pro-grams were not ready for such indi-viduals and were not motivated tomatch their needs.

Contemplation is the stage inwhich people are intending tochange in the next 6 months. Theyare more aware of the pros of chang-ing but are also acutely aware of thecons. This balance between the costsand benefits of changing can pro-duce profound ambivalence that cankeep people stuck in this stage forlong periods of time. We often char-acterize this phenomenon as chroniccontemplation or behavioral procras-tination. These folks are also notready for traditional action-orientedprograms.

Preparation is the stage in which

people are intending to take actionin the immediate future, usually mea-sured as the next month. They havetypically taken some significant ac-tion in the past year. These individu-als have a plan of action, such asjoining a health education class, con-sulting a counselor, talking to theirphysician, buying a self-help book, orrelying on a self-change approach.These are the people we should re-cruit for such action-oriented pro-grams as smoking cessation, weightloss, or exercise.

Action is the stage in which peo-ple have made specific overt modifi-cations in their life styles within thepast 6 months. Since action is observ-able, behavior change often has beenequated with action. But in the trans-theoretical model, action is only oneof six stages. Not all modifications ofbehavior count as action in this mod-el. People must attain a criterion thatscientists and professionals agree issufficient to reduce risks for disease.In smoking, for example, the fieldused to count reduction in the num-ber of cigarettes as action, or switch-ing to low tar and nicotine cigarettes.Now, the consensus is clear--only to-tal abstinence counts. In the dietarea, there is a consensus that lessthan 30% of calories should be con-sumed from fat. But there are thosewho believe that this guideline needsto be lowered to 25% or even 20%.

Maintenance is the stage in whichpeople are working to prevent re-lapse but they do not apply changeprocesses as frequently as do peoplein action. They are less tempted torelapse and increasingly more confi-dent that they can continue theirchanges. Based on temptation andself-efficacy data, we estimated thatmaintenance lasts from 6 months toabout 5 years. While this estimatemay seem somewhat pessimistic, lon-gitudinal data in the 1990 SurgeonGeneral’s report gave some supportto this temporal estimate. 4 After 12months of continuous abstinence,the percentage of individuals who re-turned to regular smoking was 43%.It was not until 5 years of continuousabstinence that the risk for relapsedropped to 7%.

In one of our early articles, wegave the misleading impression that

we viewed relapse as a separate stage.Relapse is one form of regression,which is a return to an earlier stage.Relapse is the return from action ormaintenance to an earlier stage. Thebad news is that relapse tends to bethe rule when action is taken formost health behavior problems. Thegood news is that for smoking andexercise only about 15% of peopleregress all the way to the precontem-plation stage. The vast majority re-turn to contemplating or preparingfor another serious attempt at action.

Termination is the stage in whichindividuals have zero temptation and100% self-efficacy. No matter whetherthey are depressed, anxious, bored,lonely, angry, or stressed, they aresure they will not return to their oldunhealthy habit as a way of coping. Itis as if they never acquired the habitin the first place. In a study of for-mer smokers and alcoholics, wefound that less than 20% of eachgroup had reached the criteria ofzero temptation and total self-effica-cy.-~ The criteria may be too strict, orit may be that this stage is an idealgoal for the majority of people. Inother areas, like exercise, consistentcondom use, and weight control, therealistic goal may be a lifetime ofmaintenance. Since termination maynot be a practical reality for a majori-ty of people, it has not been given asmuch emphasis in our research.

Processes of ChangeProcesses of change are the covert

and overt activities that people use toprogress through the stages. Process-es of change provide importantguides for intervention programs,since the processes are like the inde-pendent variables that people needto apply to move from stage to stage.Ten processes have received the mostempirical support in our research todate.6

Consciousness Raising involves in-creased awareness about the causes,consequences, and cures for a partic-ular problem behavior. Interventionsthat can increase awareness includefeedback, education, confrontation,interpretation, bibliotherapy, and me-dia campaigns.

Dramatic Relief initially produces in-creased emotional experiences foi-

September/October 1997, Vol. 12, No. 1 39

lowed by reduced affect if appropri-ate action can be taken. Psychodra-ma, role playing, grieving, personaltestimonies, and media campaignsare examples of techniques that canmove people emotionally.

Self-reevaluation combines both cog-nitive and affective assessments ofone’s self-image with and without aparticular unhealthy habit, such asone’s image as a couch potato andan active person. Value clarification,healthy role models, and imagery aretechniques that can move people eval-uatively.

Environmental Reevaluation com-bines both affective and cognitive as-sessments of how the presence or ab-sence of a personal habit affectsone’s social environment such as theeffect of smoking on others. It canalso include the awareness that onecan serve as a positive or negativerole model for others. Empathy train-ing, documentaries, and family inter-ventions can lead to such reassess-ments.

A brief television spot from Cali-fornia’s antitobacco campaign wasdesigned to help smokers in precon-templation to progress. In this spot, amiddle-aged man clearly in grief says,"I always worried that my smokingwould cause lung cancer. I was alwaysafraid that my smoking would lead toan early death. But I never imaginedthat it would happen to my wife."Then on the screen is flashed themessage, "50,000 deaths per year dueto passive smoking"--California De-partment of Health.

There are no action directives in .this intervention but there is: (1)consciousness raising--50,000 deathsper year; (2) dramatic relief---aroundgrief, guilt, and fear that can be re-duced if appropriate action is taken;(3) self-reevaluation--how do I thinkand feel about myself as a smoker;and (4) environmental reevalua-tion-how do I feel and think aboutthe effects of my smoking on my en-vironment.

Self-liberation is both the belief thatone can change and the commit-ment and recommitment to act onthat belief. New Year’s resolutions,public testimonies, and multiple rath-er than single choices can enhanceself-liberation or what the public calls

willpower. Motivation research indi-cates that people with two choiceshave greater commitment than peo-ple with one choice; those with threechoices have even greater commit-ment; having four choices does notfurther enhance willpower. 4 So withsmokers, for example, three excellentaction choices they can be given arecold turkey, nicotine fading, and nic-otine replacement.

Social Liberation requires an in-crease in social opportunities or al-ternatives especially for people whoare relatively deprived or oppressed.Advocacy, empowerment procedures,and appropriate policies can produceincreased opportunities for minorityhealth promotion, gay health promo-tion, and health promotion for im-poverished people. These same pro-cedures can also be used to help allpeople change such as smoke-freezones, salad bars in school lunches,and easy access to condoms and oth-er contraceptives.

Counterconditioning requires thelearning of healthier behaviors thatcan substitute for problem behaviors.Relaxation can counter stress; asser-tion can counter peer pressure; nico-tine replacement can substitute forcigarettes; and fat-free foods can besafer substitutes.

Stimulus Control removes cues forunhealthy habits and adds promptsfor healthier alternatives. Avoidance,environmental reengineering, andself-help groups can provide stimulithat support change and reduce risksfor relapse. Planning parking lotswith a 2-minute walk to the officeand putting art displays in stairwellsare examples of reengineering thatcan encourage more exercise.

Contingency Management providesconsequences for taking steps in aparticular direction. While contin-gency management can include theuse of punishments, we found thatself-changers rely on rewards muchmore than punishments. So rein-forcements are emphasized, since aphilosophy of the stage model is towork in harmony with how peoplechange naturally. Contingency con-tracts, overt and covert reinforce-ments, positive self-statements, andgroup recognition are procedures forincreasing reinforcement and the

probability that healthier responseswill be repeated.

Helping Relation,chips combine car-ing, trust, openness, and acceptanceas well as support :!or the healthy be-havior change. Rapport building, atherapeutic alliance, counselor calls,and buddy systems can be sources ofsocial support.

Decisional Balance,Decisional balance reflects the in-

dividual’s relative weighing of thepros and cons of changing. Original-ly, we relied on Janis and Mann’smodel of decision making that in-cluded four categories of pros (in-strumental gains for self and othersand approval for self and others).7The four categoric s of cons were in-strumental costs tc, self and othersand disapproval from self and others.In a long series of studies attemptingto produce this structure of eight fac-tors, we always found a much simplerstructure--just the pros and cons ofchanging.8

Self-efficacySelf-efficacy is the situation-specific

confidence people have that they cancope with high risk situations withoutrelapsing to their unhealthy or highrisk habit. This construct was inte-grated from Bandura’s self-efficacytheory.9,l0

TemptationTemptation reflects the intensity

of urges to engage, in a specific habitwhen in the midst of difficult situa-tions. In our research, we typicallyfind three factors reflecting the mostcommon types of ::empting situations:negative affect or .emotional distress,positive social situations, and crav-ing. ~ ~

The transtheoretical model hasconcentrated on five stages ofchange, 10 proces.ses of change, thepros and cons of c hanging, self-effi-cacy, and temptati3n. In addition,the model includes a measure of thetarget behavior. The transtheoreticalmodel is also base :1 on critical as-sumptions about tlae nature of behav-ior change and in:erventions thatcan best facilitate ~uch change.


Critical AssumptionsThe following are a set of assump-

tions that drive transtheoretical theo-ry, research, and practice.

(1) No single theory can account forall of the complexities of behav-ior change. Therefore, a morecomprehensive model will mostlikely emerge from an integra-tion across major theories.

(2) Behavior change is a process thatunfolds over time through a se-quence of stages.

(3) Stages are both stable and opento change, just as chronic behav-ioral risk factors are both stableand open to change.

(4) Without planned interventions,populations will remain stuck inthe early stages. There is no in-herent motivation to progressthrough the stages of intentionalchange as there seems to be instages of physical and psychologi-cal development.

(5) The majority of at-risk popula-tions are not prepared for actionand will not be served by tradi-tional action-oriented preventionprograms. Health promotion canhave much greater impacts if itshifts from an action paradigmto a stage paradigm.

(6) Specific processes and principlesof change need to be applied atspecific stages if progressthrough the stages is to occur. Inthe stage paradigm, interventionprograms are matched to eachindividual’s stage of change.

(7) Chronic behavior patterns areusually under some combinationof biological, social, and self-con-trol. Stage-matched interventionshave been primarily designed toenhance self-controls.

BASIC RESEARCH SUPPORT

Each of the core constructs hasbeen subjected to a wide variety ofstudies across a broad range of be-haviors and populations. Only a sam-pling of these studies can be re-viewed here.

Stage DistributionIf we are to match the needs of

entire populations, we need to know

Table 1

Distribution of Smokers by Stage Across Four Different Samples*

Precon-Sample templation Contemplation Preparation Sample Size

Random digit dial 42.1% 40.3% 17.6% 4144Four U.S. worksites 41.1% 38.7% 20.1% 4785California 37.3% 46.7% 16.0% 9534RI high schools 43.8% 38.0% 18.3% 208

* These studies assess current smokers; therefore, no respondents are in action or mainte-nance.

the stage distributions of specifichigh risk behaviors. Table 1 presentsresults from a series of studies onsmoking that have clearly demon-strated that less than 20% of smokersare in the preparation stage in mostpopulations, l’~ Approximately 40% ofsmokers are in the contemplationstage, and another 40% are in pre-contemplation. These results showthat action-oriented cessation pro-grams will not match the needs ofthe vast majority of smokers.

With a sample of 20,000 membersof an HMO, the stage distributionwas assessed for 15 health behav-iors. 1-~ While there are variations inthe distributions, for these high riskbehaviors, the results support a gen-eral rule of thumb: 40% in precon-templation, 40% in contemplation,and 20% in preparation.

Our research has focused on thestage distribution of people currentlyat risk because these are the groupstypically targeted for health promo-tion programs. There is research inthe literature on the percentages ofpopulations who were formerly atrisk but not currently at risk. For ex-ample, of ever smokers, about 45%are former smokers. The SurgeonGeneral’s Report of 1990 reports thepercent of ever smokers who quit inthe last year (57%), 1 to 5 years(10%), and more than 5 years(30%).4 While such data have epide-miological significance, they are notnearly as helpful in program plan-ning as is the stage distribution ofpopulations currently at risk.

Pros and Cons Structure Across 12Behaviors

As indicated earlier, the pros andcons of decisional balance have a

much simpler structure than Janisand Mann’s theory suggests. Acrossstudies of 12 different behaviors(smoking cessation, quitting cocaine,weight control, dietary fat reduction,safer sex, condom use, exercise ac-quisition, sunscreen use, radon test-ing, delinquency reduction, mam-mography screening, and physicianspracticing preventive medicine), thetwo-factor structure was remarkablystable. 14

Integration of Pros and Cons andStages of Change Across 12 HealthBehaviors

Stage is not a theory; it is a vari-able. A theory requires systematic re-lationships between a set of variables,ideally culminating in mathematicalrelationships. Figure 1 shows that inall 12 studies, the pros of changingare higher than the cons for peoplein precontemplation.14 In all 12 stud-ies, the pros increase between pre-contemplation and contemplation.There arc no systematic differenceson the cons between prccontcmpla-tion and contemplation. But fromcontemplation to action for all 12 be-haviors, the cons of changing arclower in action than in contempla-tion. In 11 of the 12 studies, the prosof changing are higher than the consfor people in action.

These basic findings suggest prin-ciples for progressing through thestages. To progress from precontem-plation to contemplation, the pros ofchanging must increase. To progressfrom contemplation to action, thecons of changing must decrease. Sowith people in precontcmplation, wewould target the pros for interven-tion and save the cons for after they


Figure 1

The Pros and Cons of Changing Across the Stages of Change for 12 ProblemBehaviors

progress to contemplation. Beforeprogressing to action, we would wantto see the pros and cons crossingover, with the pro., higher than thecons as a sign of being well preparedfor action.

45

40P C A M

Stage of Smoking

60

55

50

40

60

C C A MStage of Quitting Cocaine

55

Pc c A MStage of Weight Control

Stage of Reducing Fat60

55

Stages of Changing Delinquency

Stage of Safer Sex

¯ PROS

CONS

55

45

PC C A M

Stage of Condom Use60

50

40PC C A M

Stage of Using Sunscreens

6o

45

PC c A

Stage of Radon Testing

Pc c P A MStage of Exercising

so

PcStage of Mammography Screening

60

Stage of Arranging Followup Appointments

Strong and Weak Principles ofProgress

Across these saine 12 studies,mathematical relationships werefound between th,. ~ pros and cons ofchanging and progress across thestages. 1,~

The Stron[: Principle is.’PC-~ A - i[ SD T PROS

Progress from precontemplation toaction involves approximately onestandard deviation (SD) increase the pros of changing. On intelli-gence tests, a one-SD increase wouldbe 15 points, which is a substantialincrease.

The Weak Principle is:PC-~ A = .5 SD $ CONS

Progress from precontemplationto action involves approximately a.5-SD decrease in the cons of chang-ing. Because the first principle in-volves twice as gr._~at a change as thesecond, we titled the first strong andthe second weak.

Practical implications of theseprinciples are that the pros of chang-ing must increase twice as much asthe cons decrease. Perhaps twice asmuch emphasis should be placed onraising the benelits as on reducingthe costs or barr!.ers. For example, ifcouch potatoes in precontemplationcan list only five pros of exercise,then being too lzusy will be a big bar-rier to change. ]~.ut if program partic-ipants come to appreciate that therecan be more than 50 benefits for 60minutes of exercise a week, beingtoo busy becomes a relatively smallerbarrier.

Processes of Change AcrossBehaviors

One of the a.,sumptions of thetranstheoretical model is that there isa common set o~ change processespeople can applv across a broadrange of behaviors. While we have fo-cused most on 10 separate processes,


we have also examined how these 10factor together. This is called thehigher order structure of the pro-cesses. With the higher order, weconsistently find two factors: (1) expe-riential processes that include more in-ternal experiences like consciousnessraising, dramatic relief, and self-re-evaluation; and (2) behavioral processesthat include more overt activities likehelping relationships, contingencymanagement, and stimulus control.The experiential and behavioral pro-cesses have replicated across problembehaviors better than have the 10specific processes.16

Typically, we have found supportfor our standard set of 10 processesacross such behaviors as smoking,diet, cocaine use, exercise, condomuse, and sun exposure. But the struc-ture of the processes across studieshas not been as consistent as thestructure of the stages and the prosand cons of changing. In some stud-ies, we find fewer processes and occa-sionally, we find evidence for one ortwo more. It is also very possible thatwith some behaviors fewer changeprocesses may be used. With an in-frequent behavior like yearly mam-mograms, for example, fewer process-es may be required to progress tolong-term maintenance)7

Integration of Relationships BetweenStages and Processes of Change

One of our earliest empirical inte-grations was the discovery of system-atic relationships between the stagepeople were in and the processesthey were applying. This discovery al-lowed us to integrate processes fromtheories that were typically seen asincompatible and in conflict. For ex-ample, Freudian theory that reliedalmost entirely on consciousness rais-ing for producing change was viewedas incompatible with Skinnerian the-ory that relied entirely on contingen-cy management for modifying behav-ior. But self-changers did not knowthat these processes were theoretical-ly incompatible, and they taught usthat processes from very differenttheories needed to be emphasized atdifferent stages of change. Table 2presents our current empirical inte-gration. Is This integration suggeststhat in early stages, people apply cog-

Table 2

Stages of Change in Which Change Processes Are Most Emphasized

Stages of Change

Precontem-plation Contemplation Preparation Action Maintenance

Processes Consciousness raisingDramatic reliefEnvironmental reevaluation

Self-reevaluationSelf-liberation

Contingency managementHelping relationshipCounterconditioningStimulus control

nitive, affective, and evaluative pro-cesses to progress through the stages.In later stages, people rely more oncommitments, conditioning, contin-gencies, environmental controls, andsocial support for progressing towardtermination.

Table 2 has important practicalimplications. To help people progressfrom precontemplation to cohtem-plation, we need to apply such pro-cesses as consciousness raising anddramatic relief. Applying processeslike contingency management, coun-terconditioning, and stimulus controlto people in precontemplation wouldrepresent a theoretical, empirical,and practical mistake. But for peoplein action, such strategies would rep-resent an optimal matching.

As with the structure of the pro-cesses, the integration of the process-es and stages has not been as consis-tent as the integration of the stagesand pros and cons of changing.While part of the problem may bedue to the greater complexity of inte-grating 10 processes across fivestages, the processes of change needmore basic research.

APPLICATIONS OF THETRANSTHEORETICAL MODEL:SMOKING CESSATIONINTERVENTIONS ASPROTOTYPES FOR STAGE-MATCHED PROGRAMS

Smoking is costly to individualsmokers and to society. In the UnitedStates, approximately 47 million

Americans continue to smoke. Over400,000 preventable deaths per yearare attributable to smoking.4 Global-ly, the problem promises to be cata-strophic. Of the people alive in theworld today, 500 million are expect-ed to die from this single behavior,losing approximately 5 billion yearsof life to tobacco use.v~ If we couldmake even modest gains in our sci-ence and practice of smoking cessa-tion, we could prevent millions ofpremature deaths and help preservebillions of years of life.

Currently, smoking cessation clin-ics have little impact. When offeredfor free by HMOs in the UnitedStates, such clinics recruit only 1% ofsubscribers who smoke. Such behav-ior health services simply cannotmake much difference if they treatsuch a small percentage of the prob-lem.20

Startled by such statistics, behav-ioral scientists took health promotionprograms into communities. The re-sults are now being reported, and inthe largest trials ever attempted, theoutcomes are discouraging. In theMinnesota Heart Health Program,for example, $40 million was spentwith 5 years of intervention in fourcommunities totalling 400,000 peo-ple. There were no significant differ-ences between treatment and controlcommunities on smoking, diet, cho-lesterol, weight, blood pressure, andoverall risks for cardiovascular dis-CaSe.21

What went wrong? The investiga-tors speculate that maybe they dilut-


ed their programs by targeting multi-ple behaviors. But the COMMIT trialhad no effects with its primary targetof heavy smokers and only a small ef-fect with light smokers,z’~

A closer look at participation ratesmay explain some of the disappoint-ing results. In the Minnesota study,nearly 90% of smokers in both thetreatment and control communitieshad processed media informationabout smoking in the past year. Butonly about 10% had been advised toquit by their physicians,z:~ And onlyabout 3% had participated in themost powerful behavioral programs,such as individualized and interactiveclinics, classes, and contests. In oneof the Minnesota Heart Health stud-ies, smokers were randomly assignedto one of three recruitment methodsfor home-based cessation programs.’~4

These announcements generated 1to 5% participation rates, with a per-sonalized letter doing the best. Wecannot have much impact on thehealth of our communities if we onlyinteract with a small percentage ofpopulations at high risk for diseaseand early death.

One alternative is to shift from anaction paradigm to a stage paradigm,in order to increase our reach andinteract with a much higher percent-age of populations at risk. Let us ex-amine how the stage paradigm hasbeen applied to five of the most im-portant phases of health promotionprograms.

RecruitmentRecall that action-oriented cessa-

tion programs falter in this firstphase of intervention and producelow participation rates. Table 1 re-ported results that can help explainsuch low rates. Across four differentsamples, 20% or less of smokers werein the preparation stage, v’ When weadvertise or announce action-orient-ed programs, we are explicitly or im-plicitly targeting less than 20% of apopulation. The other 80% plus areleft on their own.

In two home-based recruitmentswith approximately 5000 and 4600smokers in each study, we reachedout either by telephone alone or bypersonal letters followed by tele-phone calls, if needed, and recruited

smokers to stage-matched interven-tions. For each of five stages, theseinterventions included self-help man-uals; individualized computer feed-back reports based on assessments ofthe pros and cons, processes, self-effi-cacy, and temptations; and, for someparticipants, counselor protocolsbased on the computer reports. Us-ing these proactive recruitmentmethods and stage-matched interven-tions, we were able to generate par-ticipation rates of 82 to 85%, respec-tively (Prochaska, et al., unpublishedmanuscript; Velicer, et al., unpub-lished manuscript). Such quantumincreases in participation rates pro-vide the potential to generate un-precedented impacts with entire pop-ulations of smokers.

Population impact equals partici-pation rate times the rate of efficacyor action. "~5 If a program produced30% efficacy (such as long-term absti-nence), historically it was judged tobe better than a program that pro-duced 25% abstinence. But a pro-gram that generates 30% efficacy butonly 5% participation has an impactof only 1.5% (30% × 5%). A pro-gram that produces only 25% effica-cy but 60% participation has an im-pact of 15%. With health promotionprograms, this would be 1000%greater impact on a high risk popula-tion.

The stage paradigm would shiftour outcomes from efficacy alone toimpact. To achieve such high impact,we need to shift from reactive re-cruitment, where we advertise or an-nounce our programs and reactwhen people reach us, to proactiverecruitments, where we reach out tointeract with all potential partici-pants.

But proactive recruitment alonewon’t work. In the most intensive re-cruitment protocol to date, Lichten-stein and Hollis had physicians spendtime with each smoker just to getthem to sign up for an action-orient-ed cessation clinicY 6 If that didn’twork, a nurse spent 10 minutes per-suading each smoker to sign up, fol-lowed by 12 minutes with a videotapeand health educator and even aproactive counselor call if necessary.The base rate was 1% participation.This proactive protocol resulted in

Figure 2

Pre-therapy Stage Profiles forPremature Terminators, Appropriate

Terminators, ~nd Continuers

55

53

~ 51

~ 49

45

43

Premature Terml ~ation-- o.. Appropriate Tern ~lnation-~- Continuers

Pre-Contemplati0n ActionConten tplation Maintenance

35% of smokers ir~ precontemplationsigning up. But ortly 3% showed upand 2% finished. With a combinationof smokers in con :emplation andpreparation, 65% signed up, 15%showed up, and 111% finished.

To optimize our impacts, we needto use proactive p::otocols to recruitparticipants to programs that matchthe stage they are in. Once we gener-ate high recruitm~:nt rates, we thenhave to be concerned about high re-tention rates, lest we lose many ofthe initial participants in our healthpromotion programs.

RetentionOne of the ske~etons in the closet

of psychotherapy and behaviorchange interventions is their relative-ly poor retention cares. Across 125studies, the average retention ratewas only about 50%.27 Furthermore,this meta-analysis found few consis-tent predictors of which participantswould drop out p::ematurely andwhich would conttnue in therapy. Instudies on smoking, weight control,substance abuse, and a mixture ofDiagnostic and S~:ttistical Manual IV(DSM-IV) disordecs, stage-of-changemeasures proved ~:o be the best pre-dictors of premature termination.Figure 2 presents the stage profile ofthree groups of therapy participantsin treatment for a variety of mentalhealth problems: the pretreatmentstage profile of the entire 40% whodropped out prematurely as judgedby their therapist~ was that of pa-tients in precontemplation. The 20%


who terminated quickly but appropri-ately had a profile of patients in ac-tion. Using pretreatment stage-relat-ed measures, we were able to correct-ly predict retention status for 93% ofthe three groups (Medeiros, et al.,unpublished manuscript).

We simply cannot treat peoplewith a precontempla.tion profile as ifthey were ready for action interven-tions and expect them to stay intreatment. Relapse prevention strate-gies would be indicated with smokerswho are taking action. But those inprecontemplation are more likely toneed dropout prevention strategies.

The best strategy we have foundto promote retention is matching ourinterventions to stage of change. Infour smoking cessation studies usingsuch matching strategies, we foundwe were able to retain smokers in theprecontemplation stage at the samehigh levels as those who started inthe preparation stage (Prochaska, etal., unpublished manuscript; Velicer,et al., unpublished manuscript).

ProgressThe amount of progress partici-

pants make following health promo-tion programs is directly related tothe stage they were in at the start ofthe interventions. This stage effect is il-lustrated in Figure 3, where smokersinitially in precontemplation showthe smallest amount of abstinenceover 18 months and those in prepa-ration progress the most.2s Across 66different predictions of progress, wefound that smokers starting in con-templation were about two-thirdsmore successful than those in pre-contemplation at 6-, 12-, and18-month follow-ups. Similarly, thosein preparation were about two-thirdsmore successful than those in con-templation at the same follow-ups.’,9

These results can be used clinical-ly. A reasonable goal for each thera-peutic intervention with smokers isto help them progress one stage. Ifover the course of brief therapy theyprogress two stages, they will beabout two-and-two-thirds times moresuccessful at longer term follow-ups.29

This strategy has been taught tomore than 4000 primary care physi-cians, nurses, health educators, andphysicians’ assistants in Britain’s Na-

20

Figure 3

Percentage Abstinent over 18Months for Smokers inPrecontemplation (PC),

Contemplation (C), and PreparatiOn(C/A) Stages Before Treatment (n

570)

POINT-PREVALENT ABSTINENCE (%)BY STAGE OF CHANGE

30

oPretest 1 6 12 18

ASSESSMENT PERIODS

tional Health System. With stage-matched counseling, the strategicgoal is to help each patient progressone stage following one brief inter-vention. One of the first reports is amarked improvement in the moraleof such health promoters interveningwith all patients who smoke, abusesubstances, and have unhealthy diets(E Mason, unpublished data, 1996).These professionals now have strate-gies that match the needs of all oftheir patients, not just the minorityprepared to take action. Further-more, these professionals can assessprogress across stages in the majorityof their patients, where previouslythey experienced mostly failure whentaking action was their only measureof movement.

ProcessTo help populations progress

through the stages, we need to un-derstand the processes and principlesof change. One of the fundamentalprinciples for progress is that differ-ent processes of change need to beapplied at different stages of change.Traditional conditioning processeslike counterconditioning, stimuluscontrol, and contingency control canbe highly successful for participantstaking action but can produce resis-

tance with individuals in precontem-plation. With these individuals, moreexperiential processes like conscious-ness raising and dramatic relief canmove people cognitively and affec-tively, and help them shift to contem-plation.-~

After 15 years of research, we haveidentified 14 variables on which tointervene in order to accelerateprogress across the first five stages ofchange.-~° At any particular stage, weonly need to intervene with a maxi-mum of six variables. To help guideindividuals at each stage of change,we have developed computer-basedexpert systems that can deliver indi-vidualized and interactive interven-tions to entire populations. "~ Thesecomputer programs can be usedalone or in conjunction with counsel-ors.

OutcomesIn our first large-scale clinical tri-

al, we compared four treatments: (1)one of the best home-based action-oriented cessation programs (stan-dardized); (2) stage-matched manu-als (individualized); (3) expert tem computer reports plus manuals(interactive); and (4) counselors computers and manuals (personal-ized). We randomly assigned by stage739 smokers to one of the four treat°ments.28

In the computer condition, partic-ipants completed by mail or tele-phone 40 questions that were en-tered in our central computers andgenerated feedback reports. The re-ports informed participants abouttheir stage of change, their pros andcons of changing, and their use ofchange processes appropriate to theirstages. At baseline, participants weregiven positive feedback on what theywere doing correctly and guidanceon which principles and processesthey needed to apply more in orderto progress. In two progress reportsdelivered over the following 6months, participants also receivedpositive feedback on any improve-ment they made on any of the vari-ables relevant to progressing. So, de-moralized and defensive smokerscould begin progressing without hav-ing to quit and without having towork too hard. Smokers in the con-


Figure 4

Point Prevalence Abstinence (%) forFour Treatment Groups at Pretest

and at 6, 12, and 18 Months

2O

Pretest 6 12 18

ASSESSMENT PERIODS

templation stage could begin takingsmall steps, like delaying their firstcigarette in the morning for an extra30 minutes. They could choose smallsteps that would increase their self-ef-ficacy and help them become betterprepared for quitting.

In the personalized condition,smokers received four proactivecounselor calls over the 6-month in-tervention period. Three of the callswere based on the computer reports.On the other call, counselors report-ed much more difficulty in interact-ing with participants without anyprogress data. Without scientific as-sessments, it was much harder forboth clients and counselors to tellwhether any significant progress hadoccurred since their last interaction.

Figure 4 presents point prevalenceabstinence rates for each of the fourtreatment groups over 18 monthswith treatment ending at 6 months.28

The two self-help manual conditionsparalleled each other for 12 months.At 18 months, the stage-matchedmanuals moved ahead. This is an ex-ample of a delayed action effect, whichwe often observe with stage-matchedprograms. It takes time for partici-pants in early stages to progress allthe way to action. Therefore, sometreatment effects as measured by ac-tion will be observed only after con-siderable delay. But it is encouragingto find treatments producing thera-peutic effects months and even yearsafter treatment ended.

The computer alone and comput-

er plus counselor conditions paral-leled each other for 12 months.Then, the effects of the counselorcondition flattened out while thecomputer condition effects contin-ued to increase. We can only specu-late as to the delayed differences be-tween these two conditions. Partici-pants in the personalized conditionmay have become somewhat depen-dent on the social support and socialcontrol of the counselor calling, Thelast call was after the 6-month assess-ment, and benefits were observed at12 months. Termination of the coun-selors could result in no furtherprogress because of the loss of socialsupport and control. The classic pat-tern in smoking cessation clinics israpid relapse beginning as soon asthe treatment is terminated. Some ofthis rapid relapse could well be dueto the sudden loss of social supportor social control provided by thecounselors and other participants inthe clinic.

The next test was to demonstratethe efficacy of the expert systemwhen applied to an entire populationrecruited proactively. With over 80%of 5170 smokers participating andfewer than 20% in the preparationstage, we demonstrated significantbenefits of the expert system at each6-month follow-up (Prochaska, et al.,unpublished manuscript). Further-more, the advantages over proactiveassessment alone increased at eachfollowup for the full 2 years assessed.The point prevalence abstinencerates for the expert system at 6, 12,18, and 24 months were 9.78, 18.0,21.7, and 25.6%, respectively, com-pared to 7.4, 14.5, 16.6, and 19.7%for the assessment alone. The impli-cations here are that expert systeminterventions in a population cancontinue to demonstrate benefitslong after the intervention has end-ed.

We then showed excellent replica-tion of the expert system’s efficacy inan HMO population of 4653 smokerswith 85% recruited (Prochaska, etal., unpublished manuscript; Velicer,et al., unpublished manuscript). At18-month follow-up in the first study,the abstinence rate for the expertsystem was 21.7% vs. 16.6% for assess-ment alone. In the HMO study, the

abstinence rate fo:: the expert systemwas 23.2% vs. 17.5% for assessmentalone. The difference between theexpert system and assessment alonefor the two studie~ was 5.9 and 5.7percentage points, respectively. Thesereplicated differences were highly sig-nificant as well. ~]aile working on apopulation basis, we were able toproduce the level of success normallyfound only in intense clinic-basedprograms with low participation ratesof much more selected samples ofsmokers. The implication is that onceexpert systems ar,. ~ developed andshow effectivenes;~ with one popula-tion, they can be transferred at muchlower cost and produce replicablechanges in new Fopulations.

Enhancing Interactive InterventionsIn recent bem:hmarking research,

we have been trying to create en-hancements to o~r expert system toproduce even greater outcomes.In the first enhancement in ourHMO populatior~, we added a per-sonal hand-held ~omputer designedto bring the behavior under stimuluscontrol (Prochaska, et al., unpub-lished manuscript). This commercial-ly successful innovation was an ac-tion-oriented intervention that didnot enhance om expert system pro-gram on a poputation basis. In fact,our expert system alone was twice aseffective as the system plus the en-hancement. There are two major im-plications here: (1) more is not nec-essarily better, and (2) providing in-terventions that are mismatched tostage can make 3utcomes markedlyworse.

Counselor Enh~ ncementsIn our HMO population, counsel-

ors plus expert :;ystem computerswere outperforraing expert systemsalone at 12 months (Prochaska, etal., unpublished manuscript). But at18 months, the counselor enhance-ment had declined while the com-puters alone had increased. Both in-terventions wer,_~ producing identicaloutcomes of 23 2% abstinence, whichare excellent for an entire popula-tion. Why did the effect of the coun-selor condition drop after the inter-vention? Our leading hypothesis isthat people can become dependent


on counselors for the social supportand social monitoring that they pro-vide. Once these social influences arewithdrawn, people may do worse.The expert system computers, bycontrast, may maximize self-reliance.In a current clinical trial, we are fad-ing out counselors over time as amethod for dealing with dependencyon the counselor. If fading is effec-tive, it will have implications for howcounseling should be terminated:gradually over time rather than sud-denly.

We believe that the most powerfulchange programs will combine thepersonalized benefits of counselorsand consultants with the individual-ized, interactive, and dam-based ben-e fits of expert system computers. Butto date we have not been able todemonstrate that more costly coun-selors, who had been our most pow-erful change agents, can actually addvalue over computers alone. Thesefindings have clear implications forcost-effectiveness of expert systemsfor entire populations needinghealth promotion programs.

Interactive vs. NoninteractiveInterventions

Another important aim of theHMO project was to assess whetherinteractive interventions (computer-generated expert systems) are moreeffective than noninteractive commu-nications (self-help manuals) whencontrolling for number of interven-tion contacts (Velicer, et al., unpub-lished manuscript). At 6, 12, and 18months for groups of smokers receiv-ing a series of one, two, three, or sixinteractive vs. noninteractive con-tacts, the interactive interventions(expert system) outperformed thenoninteractive manuals in all fourcomparisons. In three of the compar-isons (1, 2, and 3), the difference 18 months was at least five percent-age points, a difference betweentreatment conditions assumed to beclinically significant. These resultsclearly support the hypothesis thatinteractive interventions will outper-form the same number of noninter-active interventions.

These results support our hypoth-esis that the most powerful healthpromotion programs for entire popu-

lations will be interactive. In the re-active clinical literature, it is clearthat interactive interventions such asbehavioral counseling produce great-er long-term abstinence rates (20 to30%) than do noninteractive inter-ventions such as self-help manuals(10 to 20)?"-’~4 It should be kept inmind that these traditional action-ori-ented programs were implicitly or ex-plicitly recruiting for populations inthe preparation stage. Our results in-dicate that even with proactively re-cruited smokers with less than 20%in the preparation stage, the long-term abstinence rates are in the 20to 30% range for the interactive in-terventions and in the 10 to 20%range for the noninteractive inter-ventions. The implications are clear.Providing interactive interventionsvia computers are likely to producegreater outcomes than relying onnoninteractive communications, suchas newsletters, media, or self-helpmanuals.

Proactive vs. Reactive ResultsWe believe that the future of

health promotion programs lies withstage-matched, proactive, and interac-tive interventions. Much greater im-pacts can be generated by proactiveprograms because of much higherparticipation rates, even if efficacyrates are lower. But we also believethat proactive programs can producecomparable outcomes to traditionalreactive programs. It is counterintu-itive to believe that comparable out-comes can be produced with peoplewho we reach out to help as withpeople who call us for help. But thatis what informal comparisons strong-ly suggest. We compared 18-monthfollow-ups for all subjects who re-ceived our three expert system re-ports in our previous reactive study2sand in our first proactive study (Pro-chaska, et al., unpublished manu-script). The abstinence curves are re-markably similar.

The results with our counselingplus computer conditions were evenmore impressive. Proactively recruit-ed smokers working with counselorsand computers had higher absti-nence rates at each follow-up thandid the smokers who had called forhelp. One of the differences is that

our proactive counseling protocolhad been revised and hopefully im-proved based on previous data andexperience. But, the point is, if wereach out and offer people improvedhealth behavior programs that areappropriate for their stage, we proba-bly can produce efficacy or absti-nence rates at least equal to those weproduce with people who reach outto us for help. Unfortunately, there isno experimental design that couldpermit us to randomly assign peopleto proactive vs. reactive recruitmentprograms. We are left with informalbut provocative comparisons.

If these results continue to be rep-licated, health promotion programswill be able to produce unprecedent-ed impacts on entire populations. Webelieve that such unprecedented im-pacts require scientific and profes-sional shifts:

(1) from an action paradigm to stage paradigm;

(2) from reactive to proactive re-cruitment;

(3) from expecting participants match the needs of our pro-grams to having our programsmatch their needs; and

(4) from clinic-based to population-based behavioral health pro-grams that still apply the field’smost powerful individualized andinteractive intervention strate-gies.

Acknowledgments

This research zoas partially supported by Grants CA50087 and CA 27821 fiom the Natio~ml Cancer Insti-tute and Grant HC 48190 fiom the National Heart,Lung, and Blood b*stitute.

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The Transtheoretical Model of Health Behavior Change€¦ · The Transtheoretical Model of Health Behavior Change James O. Prochaska, Wayne F. Velicer Abstract The transtheoretical