HEALTH BELIEF MODEL AND THEORY OF REASONED ACTION Glanz, et al. Origins of the Health Belief Model (HBM) ◦ Developed in 1950’s by social psychologists (Hochbaum, 1958) ◦ Derived from stimulus response theory and cognitive theory ◦ Value-expectancy concepts evolve (i.e. value avoiding illness/expect a specific action will prevent illness) Description of HBM Constructs ◦ Perceived Susceptibility- likelihood one will get disease or condition ◦ Perceived severity- beliefs about gravity of contracting disease/illness ◦ Perceived benefits-perceived benefits about available actions to reduce threat ◦ Perceived barriers- belief about the “costs” of advised health action ◦ Cues to action-strategies to activate readiness ◦ Self efficacy- confidence in one’s ability to take action Measurement of HBM constructs ◦ Construct definitions need to be consistent w, HBM theory conceptualized ◦ Measures need to be specific to behavior being addressed and relevant to population ◦ Measure full range of factors that may influence behavior for content validity ◦ Multiple items for each scale reduces measurement error ◦ Validity and reliability measures need to be reexamined with each study Apply the HBM constructs to the following health issues: ◦ Mammogram screening in Latina women age 40 and older ◦ Prostate cancer screening for African American men 40 and over ◦ Osteoporosis in the GW (young women only)freshman class Limitations of HBM ◦ Individual and Linear model that assumes a rational thought process ◦ HBM does not consider the emotional component of behavior ◦ Cues to action are missing from the research ◦ Relationship between severity and susceptibility is unclear (which comes first?) to determine behavioral predictors Theory of Reasoned Action (TRA)/ Theory of Planned Behavior (TPB) ◦ Ajzen and Fisbein (1975) focused on constructs concerned w, individual motivations/likelihood of performing certain behaviors ◦ TRA asserts the MOST important determinant of behavior is BEHAVIORAL INTENTION ◦ TRA focuses on cognitive factors (beliefs/values) that determine motivation (behavioral intention) ◦ Direct determinants of individuals behavioral intention is ATTITUDE toward behavior and SUBJECTIVE NORMS associated with behavior ◦ TPB adds Perceived behavioral control over behaviors taking into account situations where one may not have complete volition over behavior ◦ Postulates that perceived behavioral control is independent of behavioral intention (person’s ease/difficulty with performing behavior will affect behavioral intention) ◦ The most important determinant of behavior of IBM is Intention to perform behavior; this is typically measured in the literature ◦Apply the constructs of TPB to the following: ◦Healthy eating ◦Condom use ◦Smoking Integrated Behavioral Model ◦ Constructs include: ◦ Intention or decision to perform the behavior ◦ Attitude, Experiential Attitude, Instrumental Attitude ◦ Perceived norm, Injunctive norm, Descriptive norm ◦ Personal agency, Perceived control, Selfefficacy Construct Definition Behavioral Intention Perceived likelihood of performing behavior ATTITUDE Experiential attitude (DM) Overall affective evaluation of the behavior ATTITUDE Behavioral belief(ID) Belief behavior performance is associated with positive/negative things ATTITUDE Instrumental attitude (DM) Overall evaluation of behavior ATTITUDE Evaluation Value attached to behavioral outcome ATTITUDE Subjective Norm (DM) Do most people approve/disapprove of behavior? PERCEIVED NORM Normative belief (IM) Belief about whether each person agrees/disagrees PERCEIVED NORM Motivation to comply Motivation to do what each person thinks PERCEIVED NORM Descriptive norm (DM) Belief about if most people perform behavior PERCEIVED NORM Perceived Behavioral Control (DM) Overall measure of perceived control over behavior PERSONAL AGENCY Control belief (IM) Perceived likelihood of occurrence of each facilitating or constraining condition PESONAL AGENCY Perceived power Perceived effect of each condition in making behavioral performance difficult or easy PERSONAL AGENCY Self efficacy (DM) Overall measure of ability to perform behavior PERSONAL AGENCY Self-efficacy belief (IM) Perceived ability to overcome each constraining PERSONAL AGENCY Four types of elicitation questions for TRA/TPB/IBM ◦ Positive or negative feelings about performing behavior ◦ Positive or negative attributes or outcomes of performing the behavior ◦ Individuals who they may listen to oppose/favor behavior ◦ Situational or environmental facilitators and barriers make behavior easy or difficult to perform Limitations of TRA/TPB/IBM ◦ It does not consider the role of environmental and structural issues ◦ The linear nature of the theoretical constructs ◦ It assumes the person has acquired the opportunities and resources to be successful in performing the desired behavior, regardless of the intention ◦ The time frame between "intent" and "behavioral action" is not addressed by the theory