Experimental evidence for stages of health behavior change: the precaution adoption process model applied to home radon testing.

Hypotheses generated by the precaution adoption process model, a stage model of health behavior, were tested in the context of home radon testing. The specific idea tested was that the barriers impeding progress toward protective action change from stage to stage. An intervention describing a high risk of radon problems in study area homes was designed to encourage homeowners in the model's undecided stage to decide to test, and a low-effort, how-to-test intervention was designed to encourage homeowners in the decided-to-act stage to order test kits. Interventions were delivered in a factorial design that created conditions matched or mismatched to the recipient's stage (N = 1,897). Both movement to a stage closer to testing and purchase of radon test kits were assessed. As predicted, the risk treatment was relatively more effective in getting undecided people to decide to test than in getting decided-to-act people to order a test. Also supporting predictions, the low-effort intervention proved relatively more effective in getting decided-to-act people to order tests than in getting undecided people to decide to test.

High risk or low: how location on a "risk ladder" affects perceived risk.

Efforts to explain risk magnitude often rely on a "risk ladder" in which exposure levels and associated risk estimates are arrayed with low levels at the bottom and high ones at the top. Two experiments were conducted to test the hypothesis that perceived threat and intended mitigation vary with the location of the subject's assigned level on the risk ladder. Subjects were New Jersey homeowners, asked to assume a particular level of radon or asbestos contamination in their homes, to read a brochure explaining the risk, and then to complete a questionnaire. Both studies found that the difference between an assigned level one-quarter of the way up the ladder and the same level three-quarters of the way up the ladder significantly affected threat perception; the effect on mitigation intentions was significant in only one of the studies. Variations in assigned risk also affected threat perception and mitigation intentions. Variations in test magnitude (e.g., 15 fibers per liter vs. 450 fibers per cubic foot, roughly equivalent risks) had no effect, nor did the distinction between radon and asbestos affect the dependent variables. These findings suggest that communicators can design risk ladders to emphasize particular risk characteristics.

Predictors of home radon testing and implications for testing promotion programs.

Four data sets (total N = 3,329) are examined to identify the predictors of home radon testing. The data, interpreted in terms of a stage model of radon testing behavior, reveal that the variables predicting transitions between stages change as people move from one stage to the next. Thinking about radon testing (vs. never having even considered testing) is best predicted by general radon knowledge and by knowing other people who are concerned or have tested. Once contemplating testing, the decision to test is most closely related to the perceived likelihood of a home radon problem. Finally, there are few differences between people who say they have decided to test and those who have already tested. Instead situational factors--including difficulties in locating and choosing among test kits--appear to constitute the final barrier to testing. The ways in which these findings might assist the design of radon outreach programs are discussed, and specific outreach recommendations are advanced.

A model of the precaution adoption process: evidence from home radon testing.

We present the precaution adoption process model--a stage theory consisting of seven distinct states between ignorance and completed preventive action. The stages are "unaware of the issue," "aware of the issue but not personally engaged," "engaged and deciding what to do," "planning to act but not yet having acted," "having decided not to act," "acting," and "maintenance." The theory asserts that these stages represent qualitatively different patterns of behavior, beliefs, and experience and that the factors that produce transitions between stages vary depending on the specific transition being considered. Data from seven studies of home radon testing are examined to test some of the claims made by this model. Stage theories of protective behavior are contrasted with theories that see precaution adoption in terms of movement along a single continuum of action likelihood.

Risk communication activities of state health agencies.

Surveys concerning the risk communication practices and needs of state health agencies were completed by agency commissioners and designated staff of 48 states and territories. These data indicate that agencies are expending more effort on responding to requests for information than on initiating dialogues with interested constituencies or alerting the public to risk. The data also suggest a gap between the stated philosophy and practice of the agencies.

Emerging communication responsibilities of epidemiologists.

Epidemiologists are increasingly called upon to communicate with affected publics when designing, interpreting, and reporting their work. The author offers eight guidelines for public communication: (1) Tell the people who are most affected what you have found--and tell them first. (2) Make sure people understand what you are telling them, and what you think its implications are. (3) Develop mechanisms to bolster the credibility of your study and your findings. (4) Acknowledge uncertainty promptly and thoroughly. (5) Apply epidemiological expertise where it is called for, and do not misapply it where it is unlikely to help. (6) Show respect for public concerns even when they are not "scientific" (7) Involve people in the design, implementation, and interpretation of the study. (8) Decide that communication is part of your job, and learn the rudiments--it's easier than epidemiology.

Perceived susceptibility and self-protective behavior: a field experiment to encourage home radon testing.

Tested in a field experiment (N = 647) the hypothesis that perceptions of personal susceptibility are important in decisions to test one's home for radioactive radon gas. Experimental group subjects received a personal telephone call to tell them they lived in a high-risk area and a personal letter to reinforce the telephone message. After the intervention, experimental subjects were significantly more likely than minimal-treatment subjects to acknowledge the possibility of high radon levels in their homes. Perceptions of susceptibility and illness severity were significantly correlated with orders of radon test kits and with testing intentions. Nevertheless, there were no differences between groups in test orders or intentions. Results are discussed in terms of the difficulty of getting people to acknowledge susceptibility and the factors other than risk perceptions that influence self-protective behavior.

Optimistic biases in public perceptions of the risk from radon.

Survey data were obtained from a random sample of 657 homeowners in New Jersey and also from 141 homeowners who had already monitored their homes for radon. People who had not tested tended to believe that they were less at risk than their neighbors, and they interpreted ambiguous predictors of home radon levels in ways that supported their beliefs of below-average risk. Residents who had already tested their homes were relatively accurate about the probability of health effects. In both groups less than half of those who knew that radon can cause lung cancer were willing to admit that it would be serious if they suffered health effects from this source. The optimistic biases of the public may hamper attempts to encourage home radon monitoring and to promote appropriate mitigation measures in homes with elevated radon concentrations.

Medicine and mass communication: an agenda for physicians.

Because the medical content of the mass media significantly affects public attitudes and behavior, physicians should participate more fully as critics and sources of that content. Attempts to sway audiences with medical information alone are often unsuccessful. Communication is more likely to be effective when it offers people something they want, such as satisfaction of a need or legitimation of an existing value. Except for advertising, the media seldom engineer their impact intentionally. Instead, the producers of news and entertainment rely heavily on sources, critics, and pressure groups outside the communications industry. By mastering the patterns of media impact and the rudiments of public relations, physicians can make the media a useful tool of medicine.