• How can communicators offer explanations of risk concepts and processes that convey the intended meanings?

• How do individuals make decisions about whom they trust when seeking information about risks?

• How should risks be communicated so that affected audiences are likely to interpret the information offered as being personally relevant?

• When an information source has lost its credibility, how does that source legitimately regain trust?

Given the significant uncertainties surrounding I-131 exposure and cancer risk, the committee suggests that DHHS consider research to develop a better understanding of how people perceive the benefits and harms of cancer screening and how those perceptions are affected by different ways of presenting quantitative information and different ways of structuring clinician-patient communication. In addition to studies not specific to thyroid cancer or radiation-exposed populations, the evaluation component of the Agency for Toxic Substances and Disease Registry (ATSDR) medical-monitoring program might consider the feasibility of a controlled study to compare different information formats or different counseling strategies for patients who come in for testing.

As envisaged, the ATSDR medical-monitoring program is not likely to produce useful information about mortality effects of screening for thyroid cancer because people who are screened would be self-selected, and high long-term survival rates can be expected without screening. The program's reports on positive and negative screening results and subsequent follow-up tests, procedures, and findings should still be tracked. In considering its research priorities, DHHS might also consider an outside evaluation of patient experience and perceptions of harms and other benefits of the ATSDR program, although it is not clear that the results could be generalized.