HBHE600-881 Psychosocial Factors in Health-Related Behavior Theories and Conceptual Models Sara J. McLaughlin, PhD, MPH Department of Health Behavior and Health Education University of Michigan School of Public Health

Today’s Agenda Definition and characteristics of a… theory conceptual model Role of theories and conceptual models in health interventions Different types of variables commonly included in conceptual models

Definition of a Theory “…An attempt to explain what we see in the empirical world around us.” (p. 125) Source: Taylor, V. A., & Bengtson, V. L. (2001). Sociological perspectives on productive aging. In N. Morrow-Howell, J. Hinterlong & M. W. Sherraden (Eds.), Productive Aging: Concepts and Challenges (pp 120-144). Baltimore, MD: The John Hopkins University Press.

A theory tells us … What causes or explains the occurrence of some class of phenomena How the various factors thought to cause or explain the phenomena are related to one another Source: van Ryn, M., & Heaney, C.A. (1992). What’s the use of theory. Health Education Quarterly, 19(3), 315-330.

Theory of Reasoned Action BEHAVIORAL BELIEFS EVALUATION OF BEHAVIORAL OUTCOMES INTENTION TO PERFORM BEHAVIOR BEHAVIOR ATTITUDE TOWARD NORMATIVE MOTIVATION TO COMPLY SUBJECTIVE NORM

A few characteristics of a theory… Generalizable: Instead of being situation or context specific, a theory is applicable to a wide range of situations and contexts Testable: Must be able to test whether the specified relationships are actually true or not; can measure the various components Abstract: Typically not specified in great detail or focused on one particular phenomenon Sources: van Ryn, M., & Heaney, C.A. (1992). What’s the use of theory. Health Education Quarterly, 19 (3), 315-330; Glanz et al., Chapter 2

Theory of Reasoned Action BEHAVIORAL BELIEFS EVALUATION OF BEHAVIORAL OUTCOMES INTENTION TO PERFORM BEHAVIOR BEHAVIOR ATTITUDE TOWARD NORMATIVE MOTIVATION TO COMPLY SUBJECTIVE NORM

Constructs and Variables: Definitions Constructs: The core components of a specific theory Variables: The operational form of constructs; in other words, how the construct is measured Source: Glanz et al., Chapter 2

Theory of Reasoned Action BEHAVIORAL BELIEFS EVALUATION OF BEHAVIORAL OUTCOMES INTENTION TO PERFORM BEHAVIOR BEHAVIOR ATTITUDE TOWARD NORMATIVE MOTIVATION TO COMPLY SUBJECTIVE NORM

Theories can… Help you understand why people may or may not be engaging in optimal health behaviors Highlight things you should consider when developing interventions to promote healthier behaviors Can provide focus Sources: Earp and Ennett,1991; Glanz et al., Chapter 2

A conceptual model is… “a diagram of proposed causal linkages among a set of concepts believed to be related to a particular public health problem.” Source: Earp and Ennett, 1991, p.164

The Fathers and Sons Intervention Program Model. Caldwell C H et al. Health Educ. Res. 2004;19:644-656 Health Education Research Vol.19 no.6, © Oxford University Press 2004; All rights reserved

Theories vs. Conceptual Models Theories are general; a single behavioral theory encompasses a wide range of behaviors, populations, and settings Conceptual models are specific; they focus on a particular behavior in a distinct population and setting Sources: Earp and Ennett, 1991; Glanz et al., Chapter 2

Conceptual models… Help us organize our thinking about the causes of a particular problem or the factors that influence a behavior Summarize and integrate what we know about a particular phenomenon Relationships among the factors believed to influence a behavior or health problem are clearly specified Can help us design more effective interventions and research studies Sources: Earp and Ennett, 1991

Steps in Developing a Conceptual Model Step I. Outcome Identification Step II. Identification of Factors that Influence the Outcome Existing research; personal knowledge and experience; theories Step III. Specify the Relationships (i.e., draw arrows) among Identified Factors Existing research; existing conceptual models; theories; Personal knowledge and experience Sources: Earp and Ennett, 1991

Steps in Developing a Conceptual Model Step IV. Review Model and Begin Narrowing the Focus Cannot address every aspect of a problem What is most important? What can you realistically expect to accomplish? Model is limited to those aspects of the problem that are addressed in your study or intervention Model development is not easy. Will involve several (if not many) attempts before you arrive at your “final” model. Sources: Earp and Ennett, 1991

Six Types of Variables in Conceptual Models… Outcome or Dependent Variable: The factor that is the focus of your study or intervention Predictor or Independent Variable: A factor that causes or influences the outcome of interest

Example A Predictor Outcome Physician Advice Exercise

Six Types of Variables in Conceptual Models… 3. Antecedent Variable: A factor that precedes the predictor/independent variable of interest

Example B

Six Types of Variables in Conceptual Models… 4. Mediating Variable: A variable that comes between the predictor and outcome A mediating variable is caused by the predictor and at least partially explains how the predictor causes the outcome

Example C Stress Obesity Predictor Outcome Stress Dietary Intake Mediator

Six Types of Variables in Conceptual Models… Modifying Variable: A factor that changes or “modifies” the relationship between the predictor and outcome

Example D Antecedent Physician Training Predictor Outcome Physician Advice Exercise Exercise Knowledge Modifier

Six Types of Variables in Conceptual Models… 6. Confounding Variable – A variable that is related to both the predictor and outcome variable that when not accounted for may result in a misleading association between a predictor and outcome

Example E Predictor Smoking Outcome Safe Sex Practices Alcohol Consumption Predictor Smoking Outcome Safe Sex Practices Confounding Variable

See you next time…