Linda W. Pickle

Snuff Dipping and Oral Cancer among Women in the Southern United States

A case-control study in North Carolina involving 255 women with oral and pharyngeal cancer and 502 controls revealed that the exceptionally high mortality from this cancer among white women in the South is primarily related to chronic use of snuff. The relative risk associated with snuff dipping among white nonsmokers was 4.2 (95 per cent confidence limits, 2.6 to 6.7), and among chronic users the risk approached 50-fold for cancers of the gum and buccal mucosa--tissues that come in direct contact with the tobacco powder. In the absence of snuff dipping, oral and pharyngeal cancer resulted mainly from the combined effects of cigarette smoking and alcohol consumption. The carcinogenic hazard of oral snuff is of special concern in view of the recent upswing in consumption of smokeless tobacco in the United States.

PASSIVE SMOKING AND LUNG CANCER

Evidence that environmental tobacco smoke may be a risk factor for lung cancer among individuals who themselves have never smoked tobacco products has been the subject of expert review over the last decade by several United States and international agencies. The most recent comprehensive review, published in 1993 by the United States Environmental Protection Agency, concluded that environmental tobacco smoke is a Group A (known human) carcinogen. This report, coming in the midst of rapid social and political change in attitudes towards public policy implications for protecting human health, has been the subject of considerable discussion. Issues involved in these discussions, as well as more recently published studies on the topic, are reviewed with respect to current thinking about the risk of lung cancer in passive smokers, particularly women, who are lifetime never-smokers.

Atlas of United States mortality

This monograph presents maps of the leading causes of death in the United States for the period 1988-92....In this atlas information previously available only in tabular form or summarized on a single map is presented on multiple maps and graphs. Broad geographic patterns by age group are highlighted by application of a new smoothing algorithm and the geographic unit for mapping is defined on the basis of patterns of health care. These new features allow the public health researcher to examine the data at several geographic levels--to read an approximate rate for an area to discern clusters of similar-rate areas to visualize broad geographic patterns and to compare regional rates. Separate maps are included showing mortality from all the leading causes of death by sex and race. (EXCERPT)

Evaluation of methods for classifying epidemiological data on choropleth maps in series

Our research goal was to determine which choropleth classification methods are most suitable for epidemiological rate maps. We compared seven methods using responses by fifty-six subjects in a two-part experiment involving nine series of U.S. mortality maps. Subjects answered a wide range of general map-reading questions that involved individual maps and comparisons among maps in a series. The questions addressed varied scales of map-reading, from individual enumeration units, to regions, to whole-map distributions. Quantiles and minimum boundary error classification methods were best suited for these general choropleth map-reading tasks. Natural breaks (Jenks) and a hybrid version of equal-intervals classing formed a second grouping in the results, both producing responses less than 70 percent as accurate as for quantiles. Using matched legends across a series of maps (when possible) increased map-comparison accuracy by approximately 28 percent. The advantages of careful optimization procedures in choropleth classification seem to offer no benefit over the simpler quantile method for the general map-reading tasks tested in the reported experiment.

Visualizing georeferenced data: representing reliability of health statistics

The power of human vision to synthesize information and recognize pattern is fundamental to the success of visualization as a scientific method. This same power can mislead investigators who use visualization to explore georeferenced data—if data reliability is not addressed directly in the visualization process. Here, we apply an integrated cognitive-semiotic approach to devise and test three methods for depicting reliability of georeferenced health data. The first method makes use of adjacent maps, one for data and one for reliability. This form of paired representation is compared to two methods in which data and reliability are spatially coincident (on a single map). A novel method for coincident visually separable depiction of data and data reliability on mortality maps (using a color fill to represent data and a texture overlay to represent reliability) is found to be effective in allowing map users to recognize unreliable data without interfering with their ability to notice clusters and characterize patterns in mortality rates. A coincident visually integral depiction (using color characteristics to represent both data and reliability) is found to inhibit perception of clusters that contain some enumeration units with unreliable data, and to make it difficult for users to consider data and reliability independently.

Dietary vitamins A and C and lung cancer risk in Louisiana.

The authors describe the results of a hospital‐based incident case‐control study of lung cancer conducted in a high‐risk region of southern Louisiana from January 1979 through April 1982. Dietary intake of carotene, retinol, and vitamin C was estimated from food frequency questionnaires administered to 1253 cases and 1274 controls. An inverse association was found between level of carotene intake and lung cancer risk, and this protective effect was specific for squamous and small cell carcinoma (odds ratio (OR) = 0.84, 95% confidence interval: 0.64–1.09, high intake). A stronger protective effect for these tumors was associated with dietary vitamin C intake (OR = 0.65, 0.50–0.87, high intake). A significant inverse gradient in risk with retinol intake was limited to adenocarcinoma (OR = 0.64, 0.44–0.94, high intake) and more pronounced among blacks.

Mapping Mortality: Evaluating Color Schemes for Choropleth Maps

Use of color for representing health data on maps raises many unanswered questions. This research addresses questions about which colors allow accurate map reading and which colors map users prefer. Through the combination of a review of previous color research and an experiment designed to test specific combinations of colors on maps, criteria were established and evaluated for selecting colors for choropleth maps of mortality data. The color-selection criteria provide pairs of hues for diverging schemes that avoid naming and colorblind confusions. We also tested sequential and spectral schemes. Our results show that color is worth the extra effort and expense it adds to map making because it permits greater accuracy in map reading. In addition, people prefer color maps over monochrome maps. Interestingly, scheme preference is affected by levels of clustering within mapped distributions. In this research, people preferred spectral and purple/green hue combinations. Contrary to our expectations, spectral ...

Current practices in spatial analysis of cancer data: mapping health statistics to inform policymakers and the public

BackgroundTo communicate population-based cancer statistics, cancer researchers have a long tradition of presenting data in a spatial representation, or map. Historically, health data were presented in printed atlases in which the map producer selected the content and format. The availability of geographic information systems (GIS) with comprehensive mapping and spatial analysis capability for desktop and Internet mapping has greatly expanded the number of producers and consumers of health maps, including policymakers and the public.Because health maps, particularly ones that show elevated cancer rates, historically have raised public concerns, it is essential that these maps be designed to be accurate, clear, and interpretable for the broad range of users who may view them. This article focuses on designing maps to communicate effectively. It is based on years of research into the use of health maps for communicating among public health researchers.ResultsThe basics for designing maps that communicate effectively are similar to the basics for any mode of communication. Tasks include deciding on the purpose, knowing the audience and its characteristics, choosing a media suitable for both the purpose and the audience, and finally testing the map design to ensure that it suits the purpose with the intended audience, and communicates accurately and effectively. Special considerations for health maps include ensuring confidentiality and reflecting the uncertainty of small area statistics. Statistical maps need to be based on sound practices and principles developed by the statistical and cartographic communities.ConclusionThe biggest challenge is to ensure that maps of health statistics inform without misinforming. Advances in the sciences of cartography, statistics, and visualization of spatial data are constantly expanding the toolkit available to mapmakers to meet this challenge. Asking potential users to answer questions or to talk about what they see is still the best way to evaluate the effectiveness of a specific map design.

A New Method of Estimating United States and State‐level Cancer Incidence Counts for the Current Calendar Year

The American Cancer Society (ACS) has published the estimated number of new cancer cases and deaths in the current year for the United States that are commonly used by cancer control planners and the media. The methods used to produce these estimates have changed over the years as data (incidence) and statistical models improved. In this paper we present a new method that uses statistical models of cancer incidence that incorporate potential predictors of spatial and temporal variation of cancer occurrence and that account for delay in case reporting and then projects these estimated numbers of cases ahead 4 years using a piecewise linear (joinpoint) regression method. Based on evidence presented here that the new method produces more accurate estimates of the number of new cancer cases for years and areas for which data are available for comparison, the ACS has elected to use it to estimate the number of new cancer cases in Cancer Facts & Figures 2007 and in Cancer Statistics, 2007.

Lung cancer risk associated with cancer in relatives

Family history data from an incident case-control study of lung cancer conducted in the Texas Gulf Coast region between 1976 and 1980 were analyzed to evaluate the contribution of cancer in first-degree relatives to lung cancer risk. Odds ratios (OR) increased slightly as the number of relatives with any cancer increased (reaching 1.5 with 4 or more relatives with cancer). Risks were higher for tobacco-related cancers (OR = 1.5 for 2 or more relatives with these tumors) and greatest for first-degree relatives with lung cancer (OR = 2.8 for lung cancer in 2 or more relatives). For cases of squamous cell carcinoma and adenocarcinoma of the lung, risks with 3 or more relatives with any cancer were increased 2-fold (OR = 1.8 and 1.9 respectively), and a significantly elevated risk was found for having a first-degree relative with lung cancer for each histologic type (ORs from 1.7-2.1). Having a spouse with lung cancer increased lung cancer risk (OR = 2.5), and cases with lung cancer reported in a first-degree relative were diagnosed at an earlier age, as were case siblings with lung cancer.