Public requests for cancer cluster investigations: a survey of state health departments

Investigating reports of cancer clusters in Canada: a qualitative study of public health communication practices and investigation procedures

INTRODUCTION:

Public health officials provide an important public service responding to community concerns around cancer and often receive requests to investigate patterns of cancer incidence and communicate findings with citizens. In this study, we identified procedures Canadian public health officials followed when investigating reports of cancer clusters, and explored the challenges officials faced conducting risk communication with communities.

METHODS:

Thirteen interviews were administered by telephone with 15 officials across Canadian jurisdictions and analyzed using thematic analysis. A content analysis of procedural documents received from five provinces was also undertaken.

RESULTS:

A third of provinces/territories in this study did not use any consistent guidelines to investigate reports of cancer clusters, a third used their own guidelines and a third used guidelines from other countries. Each Canadian jurisdiction identified a different agency or individual responsible for investigating cluster inquiries. Officials in most interviews considered public education to be the primary objective of risk communication during an investigation. Officials in only 4 of 13 interviews cited an overall positive response from the public after investigating reports of a cancer cluster.

CONCLUSION:

Differences in practices used to investigate suspected cancer clusters by public health officials were revealed in this work. Establishing pan-Canadian cancer cluster guidelines could improve procedural consistency across jurisdictions and offer enhanced opportunities to compare cluster responses for evaluation. A reporting system to track reported clusters may improve information sharing between federal, provincial/territorial and local investigators. During formal investigations, face-to-face participatory communication approaches should be explored to improve citizen engagement and manage community concerns.

An investigation of cancer rates in the Argentia region, Newfoundland and Labrador: an ecological study

BACKGROUND

The Argentia region of Newfoundland and Labrador, Canada, was home to a US naval base during a 40-year period between the 1940s and the 1990s. Activities on the base resulted in contamination of the soil and groundwater in the region with chemicals such as heavy metals and dioxins, and residents have expressed concern about higher rates of cancer in their community. This study investigated the rate of cancer diagnosis that is disproportionately high in the Argentia region.

METHODS

Cases of cancer diagnosed between 1985 and 2011 were obtained for the Argentia region, two comparison communities, and the province of Newfoundland and Labrador. Crude and age-standardized incidence rates of cancer diagnosis were calculated and compared. The crude incidence rate was adjusted for differences in age demographics using census data, and age-standardized incidence rates were compared.

RESULTS

Although the Argentia region had a higher crude rate of cancer diagnosis, the age-standardized incidence rate did not differ significantly from the comparison communities or the provincial average. Argentia has an aging population, which may have influenced the perception of increased cancer diagnosis in the community.

CONCLUSIONS

We did not detect an increased burden of cancer in the Argentia region.

Stop and listen to the people: an enhanced approach to cancer cluster investigations

Cancer cluster investigations need to address the disconnect between traditional public health approaches and human needs. Cancer cluster investigations often magnify fear and uncertainty because they rarely find a definitive environmental cause. Traditional approaches emphasize population-level data analysis and undervalue active listening. Because few studies have explored active listening in cancer cluster investigations, we conducted a descriptive oral history case study of a Frederick, Maryland, investigation. We interviewed 12 community members and 9 public health professionals about the investigation of a perceived cancer cluster. Many believed it was linked to environmental contamination at Fort Detrick, a local US Army base. We propose enhanced active listening that seeks out peoples' perspectives, validates their concerns, and engages them in the investigative process.

Cancer cluster investigations: review of the past and proposals for the future

Residential clusters of non-communicable diseases are a source of enduring public concern, and at times, controversy. Many clusters reported to public health agencies by concerned citizens are accompanied by expectations that investigations will uncover a cause of disease. While goals, methods and conclusions of cluster studies are debated in the scientific literature and popular press, investigations of reported residential clusters rarely provide definitive answers about disease etiology. Further, it is inherently difficult to study a cluster for diseases with complex etiology and long latency (e.g., most cancers). Regardless, cluster investigations remain an important function of local, state and federal public health agencies. Challenges limiting the ability of cluster investigations to uncover causes for disease include the need to consider long latency, low statistical power of most analyses, uncertain definitions of cluster boundaries and population of interest, and in- and out-migration. A multi-disciplinary Workshop was held to discuss innovative and/or under-explored approaches to investigate cancer clusters. Several potentially fruitful paths forward are described, including modern methods of reconstructing residential history, improved approaches to analyzing spatial data, improved utilization of electronic data sources, advances using biomarkers of carcinogenesis, novel concepts for grouping cases, investigations of infectious etiology of cancer, and "omics" approaches.

Guidelines for the mapping of cancer registry data: results from a breast cancer expert panel study

CONTEXT

Small area (eg, subcounty) cancer mapping is one of the analytic services most commonly requested of cancer registries and local public health agencies, and difficulties in providing it have been noted to undermine public confidence. Although a great many statistical protocols have been published to enable this practice, none of them are in common use to generate information for the general public.

OBJECTIVES

To evaluate the utility of subcounty breast cancer mapping and articulate guidelines and a possible protocol for its implementation by cancer registries and local public health agencies.

METHODS

We convened an Expert Advisory Group of breast cancer stakeholders from around California to elicit values, priorities, and preferred characteristics of protocols for proactive subcounty breast cancer mapping. Upon formulating a protocol, we applied it to 9 years of data (2000-2008) describing invasive breast cancer in California for evaluation by the Expert Advisory Group.

RESULTS

Maps with subcounty resolution were seen to provide important information with a wide range of applications. Priorities included the avoidance of false-positive findings, scientific credibility, and the provision of information elucidating social and environmental characteristics. A protocol using Kulldorff's Scan Statistic along with postanalytic steps for refining results was elaborated; when applied to the data, 4 discrete regions with elevated rates of invasive breast cancer were identified and described.

CONCLUSIONS

Expert Advisory Group priorities were readily translatable into a scientifically rigorous protocol that protected confidentiality and avoided statistically unstable rate estimates. The resulting maps enabled participants to visualize geographically defined populations falling within and crossing county boundaries. These findings support the enactment of policies for the routine and proactive analysis of breast cancer surveillance data to provide subcounty information.

Challenges created by data dissemination and access restrictions when attempting to address community concerns: individual privacy versus public wellbeing

BACKGROUND

Population health data are vital for the identification of public health problems and the development of public health strategies. Challenges arise when attempts are made to disseminate or access anonymised data that are deemed to be potentially identifiable. In these situations, there is debate about whether the protection of an individual's privacy outweighs potentially beneficial public health initiatives developed using potentially identifiable information. While these issues have an impact at planning and policy levels, they pose a particular dilemma when attempting to examine and address community concerns about a specific health problem.

METHODS

Research currently underway in northern Canadian communities on the frequency of Helicobacter pylori infection and associated diseases, such as stomach cancer, is used in this article to illustrate the challenges that data controls create on the ability of researchers and health officials to address community concerns.

RESULTS

Barriers are faced by public health professionals and researchers when endeavouring to address community concerns; specifically, provincial cancer surveillance departments and community-driven participatory research groups face challenges related to data release or access that inhibit their ability to effectively address community enquiries. The resulting consequences include a limited ability to address misinformation or to alleviate concerns when dealing with health problems in small communities.

CONCLUSIONS

The development of communication tools and building of trusting relationships are essential components of a successful investigation into community health concerns. It may also be important to consider that public wellbeing may outweigh the value of individual privacy in these situations. As such, a re-evaluation of data disclosure policies that are applicable in these circumstances should be considered.

The role of public health and how boundary analysis can provide a tool for public health investigations: the public health perspective

The rapidly expanding capabilities to analyze geocoded data are opening many possibilities to provide revolutionary improvements in the ability to monitor health events over time and space. The role of public health and what science based public health intervention means is reviewed. The type of information that is useful to public health planners is discussed. How geospatial analysis fits in with the process of developing public health programs and how the public health field can use these advances in analytical techniques, associated software and available geocoded data is discussed. The value of boundary analysis as an analytical tool is assessed from the public health perspective. Why the ability to determine geographically associated event clusters and to identify the boundaries of clusters, independent of any predetermined polygon, establishes the best information possible for assessing health event data, planning interventions and monitoring the outcomes of intervention efforts is discussed.

Are cancer registries unconstitutional?

Population-based cancer registration, mandated throughout the United States, is central to quantifying the breadth and impact of cancer. It facilitates research to learn what causes cancer to develop and, in many cases, lead to death. However, as concerns about privacy increase, cancer registration has come under question. Recently, its constitutionality was challenged on the basis of 1) the vagueness of statutory aims to pursue public health versus the individual privacy interests of cancer patients, and 2) the alleged indignity of one's individual medical information being transmitted to government authorities. Examining cancer registry statutes in states covered by the US National Cancer Institute's SEER Program and the US Centers for Disease Control and Prevention's National Program of Cancer Registries, we found that cancer registration laws do state specific public health benefits, and offer reasonable limits and safeguards on the government's possession of private medical information. Thus, we argue that cancer registration would survive constitutional review, is compatible with the civil liberties protected by privacy rights in the U.S., satisfies the conditions that justify public health expenditures, and serves human rights to enjoy the highest attainable standards of health, the advances of science, and the benefits of government efforts to prevent and control disease.

Individual- and community-level effects on risk perception in cancer cluster investigations

This article focuses on the relative influence of individual versus community effects on risk perception. The study is grounded in literature examining how individuals manage information and make risk judgments in the context of suspected environmental cancer threats. We focus on three individual-level perspectives: the psychometric model of risk perception, an adaptation of the heuristic-systematic information processing model, and cancer anxiety. We also evaluate five sets of community-level variables that frame cancer cluster investigations: demographic, epidemiologic, sociologic, etiologic, and pathologic. Data were collected through a mail survey of 30 communities in which cancer cluster investigations were being conducted. Response rates averaged 43%, with 1,111 records in the final data set. Through multilevel modeling and other techniques, the results show that the individual-level model developed in previous work remains a robust description of risk perception in these cases. However, the analysis also shows that the community-level measures neither improve the individual-level model nor offer any substantial explanatory power of their own. We provisionally conclude that, within the context of cancer cluster investigations, risk perception is a phenomenon located in a common psychological dimension that is substantially independent of contextual influences. We also suggest that risk communication efforts in this specific context might successfully draw from a common approach informed more by individual than community factors.

Public meetings about suspected cancer clusters: the impact of voice, interactional justice, and risk perception on attendees' attitudes in six communities

Holding a public meeting is a frequent method of communicating with community residents during official investigations into possible cancer clusters; however, there has been little formal research into the effectiveness of this method of health communication. This article presents research examining the influence of public meetings held during ongoing cancer cluster investigations in six U.S. communities. Drawing on social psychological theories of organizational justice, it examines the degree to which three specific elements of justice, including having a voice in the process, receiving fair interactional treatment, and facing equal risk of loss (i.e., cancer), influenced five outcome variables: meeting satisfaction, community connectedness, willingness to accept meeting outcomes or recommendations, willingness to attend future public meetings, and concern about the potential cancer cluster. The analysis of data collected from meeting attendees who responded to the mailed survey (N = 165) confirms a strong role for justice concerns in public meeting evaluations. In particular, perceptions of voice and interactional treatment had consistently large effects on the outcome variables, suggesting that managing a fair public engagement process can contribute to positive civic outcomes even during periods of heightened community concern about area cancer rates.

Cancer anxiety and the perception of risk in alarmed communities

Cancer is a significant public health topic and is frequently a factor in public reactions to environmental hazards. It may be reasonable to suggest that a unique form of health anxiety exists - one specific to cancer. In this article, we explore a measure of cancer anxiety that has applicability to risk perception in the specific context of communities that are alarmed over suspect cancer rates thought to be associated with environmental hazards. A literature search was used to identify survey questions previously used to measure cancer worry, fear, anxiety, etc. A list of 24 items was employed in a mail survey sent to 30 communities in which cancer rates were under investigation (part of a broader study). An analysis of the dataset of 1,111 responses yields two versions of a cancer anxiety scale: one an additive combination of 21 items (alpha= 0.77) and the other a two-factor model consisting of nine- and four-item subscales (alpha= 0.74 and 0.69). The resulting scales are evaluated for their ability to predict perception of risk from the environmental hazards in these cases. Controlling for age, sex, and cancer status, the scales explain between 2% and 10% of risk perception (full R(2) values ranging from 0.17 to 0.24). Given the range of concepts required to model risk perception, we conclude that this measure of cancer anxiety is sufficiently reliable and robust to be recommended for use in circumstances involving hazards associated with cancer. Other uses and further development of the measure are discussed.

Adequacy of state capacity to address noncommunicable disease clusters in the era of environmental public health tracking

OBJECTIVES

We sought to assess the capacity of state public health agencies to address noncommunicable disease clusters (NCCs) and to develop recommendations to enhance agencies' NCC response capacity.

METHODS

We conducted an inventory of state public health agency Web sites and administered a Web-based survey of state health agency personnel to examine NCC capacity with respect to responsibility and authority, scope, protocols, trends in NCC investigations, and desired assistance.

RESULTS

Twenty-six of the state agency Web sites listed an NCC contact, and 12 mentioned a cluster response team. Thirty-seven states completed the Web-based survey, all addressed cancer clusters, and 30 also responded to other NCCs, such as multiple sclerosis, amyotrophic lateral sclerosis, and autism.

CONCLUSIONS

NCCs are of key concern to communities, and all of the survey respondents indicated that citizen reports were an impetus for investigations; yet, state-level capacity to address NCCs was inconsistent and disjointed. State agency personnel were committed to responding to NCC inquiries but were hampered by lack of personnel, resources, and prescribed protocols, as well as inadequate interagency communication. We offer recommendations to address these challenges.

Environmental policies, politics, and community risk perception: case study of community contamination in Casper, Wyoming

OBJECTIVES

We identify and explain factors that affected a community's perception of risk due to extensive industrial contamination and people's distrust of government agencies regarding the environmental investigations.

METHODS

Intrinsic bounded case study methodology was used to conduct research about extensive environmental contaminations due to activities of an oil refinery in North Casper, Wyoming, and the citizens' response. Data were collected from multiple sources that included public testimonies, observations, public hearings and meetings minutes, newspaper articles, archived records obtained from federal and state environmental and health agencies, as well as industry records obtained through Freedom of Information Act (FOIA) requests.

FINDINGS

The overarching theme that emerged was lack of trust due to several critical events and factors such as no response or delay in response time to community concerns, lack of transparency, perceived cover up, vague and fragmented communication by government and state officials, perception of pro-industry stance, and perceived unfair treatment.

DISCUSSION AND CONCLUSION

People's perception of environmental risks and their willingness to accept official explanations and outcomes of environmental investigations are strongly affected by their direct experiences with government agencies and the evidence of influence the powerful industries exert over relevant investigations. The government cannot successfully address public and community concerns about environmental health impacts of contaminations and in turn the public perception of risk unless it adopts and implements policies, procedures, and protocols that are clear, timely, transparent, and free from industry influence.

A heuristics approach to understanding cancer risk perception: contributions from judgment and decision-making research

BACKGROUND

The likelihood judgments that people make about their risks for cancer have important implications. At the individual level, risk estimates guide protective actions, such as cancer screening. However, at the extremes, exaggerated risk judgments can also lead to anxiety that degrades quality of life or to aggressive self-protective actions that are unwarranted given the objective risks. At the policy level, risk judgments may serve as an indicator of societal perceptions of the "war" against cancer. Using risk judgments, the public expresses its belief about whether we are winning.

PURPOSE

We present theoretical perspectives from judgment and decision making, illustrate how they can explain some of the existing empirical findings in the cancer risk literature, and describe additional predictions that have not yet been tested.

CONCLUSIONS

Overall, we suggest that theories from the judgment and decision-making perspective offer a potentially powerful view for understanding and improving risk judgments for cancer and other diseases.

Answering cluster investigation requests: the value of simple simulations and statistical tools

Cluster investigations remain an important public health issue as the number of reported clusters and public concern increase. This study shows how statistical considerations and a simulation tool may be helpful in providing communities with proper answers to the questions usually raised in such situations: How surprising is an observed childhood cancer excess? What could be learned from a statistical test? What could be learned from a case-control study? Using real demographic and incidence-rate data together with simulations based on the hypothesis that incidence rates are homogeneous, the probabilities of observing given situations were estimated. A number of real situations have been used as examples. The results of the simulation study showed, in detail, that no reliable information on the reality of an observed excess could be obtained a posteriori from a statistical test. A cluster of the same size may or may not be surprising, depending on the spatial area and time window to which the cases are related (i.e., the expected number of cases), and depending on the size of the referential territory to which this area is associated. The lack of power of a case-control study if no particular unusual exposure is present is also addressed. The approach described in this paper can easily be reproduced and adapted to many situations. It may be of assistance to health departments conducting cluster investigations and communicating with the public.

Cancer Cluster Investigations

A rural community expressed concern about a perceived excess of kidney and pancreatic cancer coupled with contamination of drinking water with atrazine, benzene, ethylene dibromide, and nitrate. Incidence and mortality for these two cancers were compared to what might be expected. A literature review was conducted for risk factors for kidney and pancreatic cancer as well as for the effects of the above 4 chemicals on these 2 cancers. Interviews with cases or surrogates ascertained chemical and risk factor exposures for these 2 cancers. Chemical exposures found in the public drinking water supply were evaluated as to their carcinogenicity. Hospital cases were compared to cases in the cancer registry. No statistically significant increases in kidney and pancreatic cancer incidence or mortality were found. The major risk factor found in the literature for these 2 cancers was smoking. Most of the cases were smokers and the chemicals found in the drinking water were not found to pose a risk for these 2 cancers. This approach provided considerable information, suggested prevention options and additional research, and is recommended for responding to cancer cluster concerns originating in the community (reactive approach). A proactive approach to cancer cluster surveillance and research was also used and is recommended for state or large local health departments.

Spatial epidemiology: current approaches and future challenges

Spatial epidemiology is the description and analysis of geographic variations in disease with respect to demographic, environmental, behavioral, socioeconomic, genetic, and infectious risk factors. We focus on small-area analyses, encompassing disease mapping, geographic correlation studies, disease clusters, and clustering. Advances in geographic information systems, statistical methodology, and availability of high-resolution, geographically referenced health and environmental quality data have created unprecedented new opportunities to investigate environmental and other factors in explaining local geographic variations in disease. They also present new challenges. Problems include the large random component that may predominate disease rates across small areas. Though this can be dealt with appropriately using Bayesian statistics to provide smooth estimates of disease risks, sensitivity to detect areas at high risk is limited when expected numbers of cases are small. Potential biases and confounding, particularly due to socioeconomic factors, and a detailed understanding of data quality are important. Data errors can result in large apparent disease excess in a locality. Disease cluster reports often arise nonsystematically because of media, physician, or public concern. One ready means of investigating such concerns is the replication of analyses in different areas based on routine data, as is done in the United Kingdom through the Small Area Health Statistics Unit (and increasingly in other European countries, e.g., through the European Health and Environment Information System collaboration). In the future, developments in exposure modeling and mapping, enhanced study designs, and new methods of surveillance of large health databases promise to improve our ability to understand the complex relationships of environment to health.

The role of epidemiology in chronic disease prevention and health promotion programs

Although the role for epidemiology is widely accepted in public health programs in general, its role in chronic disease programs is not as widely recognized. One possible barrier to improving epidemiologic capacity in chronic disease prevention and health promotion programs is that chronic disease program managers and public health decision makers may have a limited understanding of basic chronic disease epidemiology functions. We describe the assessment process of data collection, analysis, interpretation, and dissemination, and, using examples from two states, illustrate how this approach can be used to support program and policy development in three areas: by defining the problem, finding programs that work, and evaluating the effects of the program over time. Given the significant burden of chronic diseases in the United States, the scientific guidance provided by epidemiology is essential to help public health leaders identify priorities and intervene with evidence-based and effective prevention and control programs.

The function of credibility in information processing for risk perception

This study examines how credibility affects the way people process information and how they subsequently perceive risk. Three conceptual areas are brought together in this analysis: the psychometric model of risk perception, Eagly and Chaiken's heuristic-systematic information processing model, and Meyer's credibility index. Data come from a study of risk communication in the circumstance of state health department investigations of suspected cancer clusters (five cases, N = 696). Credibility is assessed for three information sources: state health departments, citizen groups, and industries involved in each case. Higher credibility for industry and the state directly predicts lower risk perception, whereas high credibility for citizen groups predicts greater risk perception. A path model shows that perceiving high credibility for industry and state-and perceiving low credibility for citizen groups-promotes heuristic processing, which in turn is a strong predictor of lower risk perception. Alternately, perceiving industry and the state to have low credibility also promotes greater systematic processing, which consistently leads to perception of greater risk. Between a one-fifth and one-third of the effect of credibility on risk perception is shown to be indirectly transmitted through information processing.

The clinical presentation of environmental health problems and the role of the pediatric provider. What do I do when I see children who might have an environmentally related illness?

The practice of environmental health is concerned with the protection of the community. There are a number of tools used for assessment of environmental hazards, but environmental health is most reliant on the use of risk assessment. Risk assessment is a set of tools used to assess hazards on a community level, based on human studies, ecological studies, or toxicity testing of animals.