Measuring Outcomes: The Role of Attitudes in Predicting Drug Use Behaviors: A Cautionary

TaleElizabeth B. Robertson, Ph.D.

Chief, Prevention Research BranchDivision of Epidemiology, Services and Prevention Research

National Institute on Drug AbuseDepartment of Health and Human Services

September 2005

Measuring Outcomes

• Often select measures that:

– Are easily implemented

– Have standard questionnaire protocols

– Have acceptable levels of validity and reliability

– Have the potential for comparison to other data sets or populations

– Place minimal burden on subjects

– Are not controversial, especially when subjects are children

Attitudes Towards Drug Use

Are easily implemented

Have standard questionnaire protocols

Have acceptable levels of validity and reliability

Have the potential for comparison to other data sets or populations

Place minimal burden on subjects

Are not controversial, especially when subjects are children

How Attitudes Influence Drug Use Among Youth

• Thus attitudes may be a good target for intervention and evaluation

• However, their impact on behavior is not direct

• Rather, attitudes can influence intentions which in turn can influence behavior

The Bottom Line

Attitudes Intentions Behavior

And now for the full story

Implied Causal Relation between Attitudes & Drug Use Behaviors

Bachman, Johnston & O’Malley, 1998, AJPH.

From 1976-1996 increase over time in marijuana use accompanied by corresponding decline in ratings of marijuana use as physically harmful and in the perceived disapproval of marijuana use.

• That graphic from the MTF study is often used as strong evidence that attitudes predict drug use

• However, there is a lot of variation in responses was not accounted for:

– Disapproval accounted for 48.5% in the difference in marijuana use

– Perceived risk accounted for 37.8% of the difference in marijuana use

• Thus, not a clear relationship

Do Drug Use Attitudes & Beliefs Predict Drug Use

Behavior?

• Predicting individual level behavior change involves complex relationships among many variables

– The situation or context in which questions are asked or in which behaviors occur can change the response or the behavior (e.g., answers to drug use attitude questions may differ if asked in the family vs. peer context)

Predicting Drug Use Behavior?

• In the early 1900’s the study of attitudes was popular

• But, there were few studies to show that that attitudes cause behavior

Early Research on Attitude-Behavior

Relationship

Attitudes = Behavior

• Review 42 studies (mixed topics related to attitudes and behaviors)

– A few studies showed the relationship between attitudes and behavior to be moderate (e.g., r= .30)

– But, the average relationship was very low (e.g., r=.15)

– Conclusion – little evidence to support the idea that people have attitudes that do not change over time and these attitudes influence their actual behavior

Alan Wicker, 1969

Early Research

• Thus, by the early 1970s the idea that attitudes cause behaviors was rejected

• BUT, these conclusions led to more research on the issue because there was obviously some relation

Early Research

From the 1960 – 70’s two main strategies for

showing how attitudes and behavior are related were

developed

Strategy #1

• Looked at how close the measure of the attitude matched the behavior – e.g., Do you think it is safe to use marijuana? versus

Do you believe it is safe to use marijuana with your friends every weekend?

– General statements show lower relation than specific

• How specific the questions were regarding the time and place– e.g., Thus, for every drug, for every context (with/without

friends) and at all possible times (weekday/weekend)

Fishbein & Ajzen, 1975; 1977

• Reviewed 109 studies – – When the closeness between attitude-behavior

measures was low there generally was no relationship

– When closeness was extremely high the relation was high

– Thus, evidence of a relation between attitudes and behavior

– BUT the relation remained unclear because the questions linking attitude to behavior were so closely worded

Ajzen & Fishbein, 1977

Using Strategy #1

• Attitude toward a behavior is related to:

– Whether you think there is a benefit or consequence of the engaging in the behavior

– Whether you care about what significant other people will think you if you engage in the behavior (perceived norm)

• Behavior is a function of:

– one’s intention to engage in the behavior

Promoting Understanding with Strategy #1

The more favorable an individual’s attitudes and perceived norms toward a behavior, the stronger the intention to perform that behavior

In General …..

Attitudes Intentions Behavior

• Behavior is not always voluntary– (e.g., a young adolescent may not want to smoke, but

given a context where many other youth are smoking, he/she may feel too much pressure to say no)

• Thus, your behavior may differ whether you think you have control over your behavior – (e.g., ability of an adolescent to say no to a peer group

drug offer without being criticized by the group)

BUT

• In a study of 113 articles (looking at a variety of behaviors)– There were very strong relationships between

attitudes and perceived control and intentions (r=.68)

– There were very strong relationships between intention and behavior (r =.62)

• Attitudes Intentions Behavior

Eagly & Chaiken, 1993; Fishbein, Chan, O’Reilly, Schnell,Wood, Beeker, Cohn, 1992; Van den Putte, 1991

Putting It All Together

• One study of attitudes and intentions among 91 adolescents aged 15-20 yrs old.

– For youth who intend to use marijuana, their intentions were much more important than beliefs about what significant others think (perceived norms)

• Youth who did not intend to use marijuana were predicted with only 40% accuracy

• Youth who intended to use marijuana were predicted with 92.5% accuracy

Example

O’Callaghan et al. (2003)

• Attitude-behavior consistency found to be higher among persons – with direct experience with an attitude target

• (e.g., for cigarette use, lighting cigarettes for Mom)

– with attitudes regarding the object that are more quickly remembered – attitudes are stronger and more well formed

• (e.g., for marijuana use, the quicker the recall about the potential pleasurable affects of use, the stronger the relationship to intention to use)

Fazio & Zanna ,1981; Fazio, Chen, McDonel, & Sherman, 1982

Strategy #2

• Predicting adolescent drug use via attitudes can also be related to other factors:

• Some important other factors:– Emotional-intellectual match

– Motivation to use drugs

– Stability of attitudes

– Perceived behavioral control

– Expected outcome

– Personality, IQ, socio-economic status, other individual differences

Attitude Other Factors Intentions Drug Use

• Had a range of effects (r= .28 to .56) on target behaviors

• MTF Longitudinal Cohort Study:

• Main mediating variable in attributing behavior is intentions

• For example, independent of baseline smoking behavior firm intentions not to smoke offered protection against risk of future smoking 3-6 years later (OR = .65-.68)

Behavioral Intentions

• MTF Longitudinal Cohort Study

• Data indicate that norms of entire school or context impact behavior

• e.g., relationship between school anti-drug use norms, disapproval of cigarettes, alcohol, marijuana use by the student body

– The school normative climate toward substance use was positively related to the probability of substance use by students

– Findings hold even after controlling for individual level attitudes of disapproval

– Thus, support for environmental interventions

A More Compelling Example

Heavy Drinking

Kumar, O’Malley, Johnston, Schulenberg, & Bachman, 2002, Prevention Science.

Other Issues to Consider

• Adolescent brain development is incomplete, with the brain centers that control emotion and decision making not being fully connected (e.g., hot cognition)

• Adolescents demonstrate relatively low attitude behavior relations because their attitudes are still developing and generally are not based on direct experience

• Youth typically associate with others they think are similar to them – find themselves in situations where acting on group attitudes is encouraged, reinforced or enforced

Implications for Evaluation of School-based Interventions

• Assessing attitudes only may lead to inaccurate conclusions

• Intentions toward a behavior, even at a relatively young age, are more potent predictors than attitudes

• Early behavioral factors (e.g., early aggression) of later behaviors (e.g., drug use) can serve as intervention targets and proxy measures

• Measures of the normative environment can also provide important proxy data at the aggregate level