Health Belief Model Malos Jaeger 17 October 2013
Health Belief Model • A value-expectancy model • Benefits – cost incurred = behavior change • Used in public health practice for greater than 50 years • Uses fear instinct response to change health-risk behaviors
Health Belief Model • Two constructs influence health behavior: • Perceived threat • Perceived susceptibility • Perceived severity • Expected net gain of adopting health behavior
Health Belief Model • Modifying factors • Age • Race • Socioeconomic status • Health knowledge • These factors can moderate perceived threat
Health Belief Model • Self-efficacy/self confidence added to model in 1988. • Cues to action
A Meta-Analysis of the Effectiveness of Health Belief Model Variables in Predicting Behavior Christopher J. Carpenter, Department of Communication, Western Illinois University Version of record first published: 09 Dec 2010
HBM (Rosenstock, 1966) • Conduct of a meta-analysis to determine if perceptions/variables/elements contained within the HBM can longitudinally predict behavior • Carpenter endeavors to resolve which HBM elements are most strongly related to health behavior • Previous studies offer conflicting findings Article Premise
Aspects of the HBM • Susceptibility and severity – individual perception of negative health outcome • Beliefs and barriers – individual perception of target behavior that reduces likelihood of negative health outcome • Cues to action • Self efficacy
Longitudinal studies • Capture change in individual perceptions of HBM elements after behavior • Carpenter holds that unless the HBM variables are measured some time before the individuals in a study make their choice to adopt the behavior or not, the results could misrepresent the ability of the HBM to predict behavior.
Current Meta-analysis/Methodology • Author evaluates accuracy of direct effects HBM through analysis of longitudinal studies • Effects of elements/variables • Possible studies for analysis culled to 18 taking place from 1982 to 2007 with 2702 participants • Moderators • Time between variable measurement and outcome behavior measurement • Type of outcome behavior (prevention v. treatment) • Drug/non drug outcome
Results • Severity – low correlation between subject’s estimate of severity and likelihood of behavior adoption • Moderator effects: • behavior of complying with drug prescription leads to greater consideration of severity • length of time between measurement of severity perception and behavior; less time indicates greater likelihood of behavior adoption
Results • Susceptibility – correlation between perception of susceptibility and behavior adoption near zero • Moderator effects • Compliance with drug prescription notes narrow positive effect • relationship between perceived susceptibility and behavior adoption further weakens over time
Results • Benefits – perception of benefits has positive correlation with likelihood of behavior adoption • Moderator effects. Weaker effect over time.
Results • Barriers – subject perception of barriers on behavior adoption largest correlation of four HBM elements • Moderator effects • Barriers weaker predictor of behavior adoption when behavior outcome was treatment v. prevention • Effect of time on relationship between barriers and behavior adoption inconsistent
Discussion • Severity, Barriers, and Benefits all related as predicted with regard to behavior adoption • Susceptibility almost always unrelated to behavior • Moderators • Time increase between perception measurement and behavior adoption measurement indicates a weakening relationship • Drug treatment studies note only instance of correlation between susceptibility and behavior adoption
Conclusion • Author’s conclusions tentative given small number of studies • Commonly used four variable HBM suffers from inconsistency and the weakness of susceptibility as a predictor • Future HBM models should examine mediation and moderation in the context of applicable variables