Cancer clusters constitute geographical areas where the frequency of cancer diagnoses during a given period of time occur more frequently than expected by chance. Cancer clusters can impact perceptions of risk and generate significant anxiety in communities. Unfortunately, cluster investigations rarely yield the answers citizens seek around a definitive cause of cancer due to the long latency of cancer and other factors. As a result, health officials may appear to be withholding information and not doing enough to address public concerns. Effective cancer risk communication may also be hindered by other stakeholders such as the media, who sometimes sensationalize risks from environmental hazards, which can distort the public’s perceptions of risks. The result may be a community dissatisfied with a cluster investigation’s results, or worse, a community that distrusts local leaders and doesn’t understand the information reported by expert officials. The four studies comprising this dissertation aimed to summarize key issues with the communication of and investigation of cancer clusters in Canada; test the impact of different types of cancer information on risk perceptions; and explore whether individual characteristics and skills were linked to positive attitudes about coping with cancer risks. An analysis of cancer news coverage and interviews with Canadian public health officials revealed that communities may be receiving inadequate and inconsistent information about cancer risks during cluster investigations. In addition, an experiment and survey revealed information trustworthiness and individuals’ numeracy and health literacy to be important factors shaping cancer risk perceptions and attitudes. This work has significant implications for risk communicators and educators seeking improved methodologies of cancer risk communication and risk education to (1) manage differences in cancer risk perceptions between experts and non-experts (2) enhance public trust in institutions and perceptions of expert competence and (3) inform future educational interventions that promote cancer coping beliefs. / Dissertation / Doctor of Science (PhD) / Cancer clusters constitute geographical areas where the frequency of cancer diagnoses during a given period of time occur more frequently than expected by chance. Cancer clusters can generate significant anxiety in communities and influence perceptions of personal safety and health. As cluster investigations rarely yield the answers citizens seek around a definitive cause of cancer, health officials may appear to be withholding information and not doing enough to address public concerns. The objectives of this dissertation were to summarize key issues with the communication of and investigation of cancer clusters in Canada; test the impact of different types of cancer information on risk perceptions; and explore whether individual characteristics, expertise and skills were linked to positive attitudes about coping with cancer risks. This work provides insights into the diverse ways that people interpret cancer information and perceive risk and identifies improved methods of conducting cancer risk communication and risk education.

In this dissertation, we consider the problem of partitioning a set of k population with respect to a control population. For this problem some multistage methodologies are proposed and their properties are derived. Using the Monte Carlo simulation techniques, the small and moderate sample size performance of the proposed procedure are studied. We have also considered at statistical surveillance of various cancers in Louisiana.

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