Health belief model

In social psychology, the health belief model (HBM) is a psychological framework used to explain and predict individuals' potentially detrimental behaviors, attitudes and beliefs on their health. Developed in the 1950s by social psychologists at the United States Public Health Service, the model examines how perceptions of susceptibility to illness, the severity of health conditions, the benefits of preventive care, and barriers to healthcare influence behavior. The HBM is widely used in health behavior research and public health interventions to understand and promote engagement in health-protective behaviors. It also incorporates concepts similar to the transtheoretical model like self-efficacy, or confidence in one's ability to take action, and identifies the role of cues to action or stimulus, such as health campaigns or medical advice, in prompting behavior change.

One of the first theories of health behavior, the HBM was developed in 1950s by social psychologists Irwin M. Rosenstock, Godfrey M. Hochbaum, S. Stephen Kegeles, and Howard Leventhal at the U.S. Public Health Service. At that time, researchers and health practitioners were worried because few people were getting screened for tuberculosis (TB), even if mobile X-ray cars went to neighborhoods. The HBM has been applied to predict a wide variety of health-related behaviors such as being screened for the early detection of asymptomatic diseases and receiving immunizations. More recently, the model has been applied to understand intentions to vaccinate (e.g. COVID-19), preventive measures to combat the spread of COVID-19 at a social gathering (such as getting tested or limiting the number of attendees) responses to symptoms of disease, compliance with medical regimens, lifestyle behaviors (e.g. sexual risk behaviors), and behaviors related to chronic illnesses, which may require long-term behavior maintenance in addition to initial behavior change. Amendments to the model were made as late as 1988 to incorporate emerging evidence within the field of psychology about the role of self-efficacy in decision-making and behavior.

The HBM theoretical constructs originate from theories in Cognitive Psychology. In early twentieth century, cognitive theorists believed that reinforcements operated by affecting expectations rather than bys affecting behavior straightly. Mental processes are severe consists of cognitive theories that are seen as expectancy-value models, because they propose that behavior is a function of the degree to which people value a result and their evaluation of the expectation, that a certain action will lead that result. In terms of the health-related behaviors, the value is avoiding sickness. The expectation is that a certain health action could prevents the condition for which people consider they might be at risk.

The following constructs of the HBM are proposed to vary between individuals and predict engagement in health-related behaviors.

Perceived susceptibility refers to subjective assessment of risk of developing a health problem. The HBM predicts that individuals who perceive that they are susceptible to a particular health problem will engage in behaviors to reduce their risk of developing the health problem. Individuals with low perceived susceptibility may deny that they are at risk for contracting a particular illness. Others may acknowledge the possibility that they could develop the illness, but believe it is unlikely.

The combination of perceived severity and perceived susceptibility is referred to as perceived threat. Perceived severity and perceived susceptibility to a given health condition depend on knowledge about the condition. The HBM predicts that higher perceived threat leads to a higher likelihood of engagement in health-promoting behaviors.

Perceived severity refers to the subjective assessment of the severity of a health problem and its potential consequences. The HBM proposes that individuals who perceive a given health problem as serious are more likely to engage in behaviors to prevent the health problem from occurring (or reduce its severity). Perceived seriousness encompasses beliefs about the disease itself (e.g., whether it is life-threatening or may cause disability or pain) as well as broader impacts of the disease on functioning in work and social roles.

Through studying Australians and their self-reporting in 2019 of receiving the influenza vaccine, researchers found that by studying perceived severity they could determine the likelihood that Australians would receive the shot. They asked, "On a scale from 0 to 10, how severe do you think the flu would be if you got it?" to measure the perceived severity and they found that 31% perceived the severity of getting the flu as low, 44% as moderate, and 25% as high. Additionally, the researchers found those with a high perceived severity were significantly more likely to have received the vaccine than those with a moderate perceived severity. Furthermore, self-reported vaccination was similar for individuals with low and moderate perceived severity of influenza.