The Precaution Adoption Process Model (PAPM)
The Precaution Adoption Process Model was developed in the late 1980s (and refined in the early 1990s) to provide a dynamic version of the HBM. Particularly, the PAPM was developed to understand people s willingness or unwillingness to conduct radon testing in their homes. It was developed to address a noted flaw in the HBM and similar models, specifically that such models only apply when an individual has already acknowledged the health problem enough to form attitudes and beliefs. An individual will not pursue radon testing if they are unaware that radon even poses a risk, or that it may exist at toxic levels in their home without their knowledge.
The PAPM aims to explain more fully how a person comes to the decision to do something about his health, and how this decision is translated into action. The PAPM focuses on individuals psychological processes. It focuses primarily on factors that are salient to individuals themselves as they proceed through the stages of the model. The PAPM begins at the beginning, before an individual is even aware of the health issue, and follows him through a series of 7 stages. Individuals are thought to move through stages sequentially - that is, an individual cannot skip past a stage to a higher one. Moreover, not all individuals will complete the model.
An individual will progress from one stage to the next based on beliefs about the costs and benefits, social norms, the skills or confidence needed to make the change, and the like. Essentially, the factors which are considered to be crucial to understanding health behavior in non-stage models are those factors which influence whether an individual will continue on from one stage to the following stage.
Stages of the PAPM

The PAPM model begins at stage 1, when an individual is unaware of the issue. As the name would suggest, people start off not knowing about certain threats to their health. An individual may never have heard of radon, or know that smoking is risky (which was actually the case in the 1960s), or have never heard of mammography. Individuals may be unaware of the issue because of personal ignorance, or because the risk of the phenomenon is unknown within the larger world.
In stage 2, the individual is aware but remain unengaged by the issue. In this stage, an individual is now aware that some phenomenon is a threat to their health, but is unconcerned by this knowledge.
In stages 3-5, an individual makes some decision about this threat to their health. First, they decide about acting (stage 3). Stage 3 is an intermediate stage in which people are aware of and engaged by a health issue. People make some decision about whether they intend to do something about this issue. People then either decide not to act (stage 4) or decide to act (stage 5). If an individual decides not to act, the model concludes here at stage 4.
Note, though, that the decision to act is not the same as acting. An individual who decides to act may then move into stage 6: acting. Here, the individual actually initiates the behavior. They quit smoking, receive a mammogram, etc.
Finally, the PAPM concludes with stage 7: maintenance. If an individual decides to act, then actually acts, the final stage of the model is for the individual to continue that health behavior - to continue not smoking, to receive regular mammograms, etc.
Evaluation and critique of the PAPM
Unfortunately, there has been little empirical examination of usefulness of the PAPM when applied to health issues. As discussed in Weinstein and Sandman piece, the model does seem to fit well for home radon testing. It has also been applied to mammography, receiving the hepatitis B vaccine, and to osteoporosis testing. One of the greatest strengths of the model is that it distinguishes people who are unaware of the issue from those who are aware but in various stages of attitude formation preceding decision making. Not only does this differentiation make sense theoretically, but these stages are distinct with regard to how best to target such people in health intervention strategies. Individuals in different stages will require different motivators in order to encourage their progression to the next stage.
However, the PAPM is not without its critics. Some argue that individuals do not always go through the fixed set of stages as this model argues. At the bare minimum, it makes sense that people may be able to move circularly - that someone who decides not to act (stage 4) may be returned to stage 3 should they have an experience that makes them reconsider the significance of the health problem. For instance, someone who smokes may decide not to quit, but upon the diagnosis of a close friend with lung cancer, he may re-assess the significance of the risk in his life and make the decision to act (stage 5) instead. Or, someone may quit smoking (stage 6) and remain smoke-free for an extended period (stage 7). But upon the experience of some traumatic or stressful incident, she may begin smoking again, only to decide a few weeks later that perhaps she should quit again. For many people, health behaviors are actually more cyclical than linear.