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D Wartenberg

Publications and source records attributed to D Wartenberg.

At least 37 records · Page 2Linked to original sources
PubMed1996

The analysis of disease clusters, Part I: State of the art.

Public health professionals often are asked to investigate apparent clusters of human health events, or "disease clusters." A cluster is an excess of cases in space (a geographic cluster), in time (a temporal cluster), or in both space and time. This is part I of an introductory-level review of the analysis of disease clusters for physicians and health professionals concerned with infection surveillance in hospitals. It reviews the status of the field with the hope of expanding the use of cluster analysis methods for the routine surveillance of infectious disease in the hospital environment.

Algorithms↗
PubMed1996

The analysis of disease clusters, Part II: Introduction to techniques.

Public health professionals often are asked to investigate apparent clusters of human health events or "disease clusters." A cluster is an excess of cases in space (a geographic cluster), in time (a temporal cluster), or in both space and time. This is the second part of an introductory-level review of the analysis of disease clusters for physicians and health professionals concerned with infection surveillance in hospitals. It reviews the status of the field with the hope of expanding the use of cluster analysis methods for the routine surveillance of infectious diseases in the hospital environment.

Cluster Analysis↗
PubMed1995

A pilot study of take-home lead exposure in New Jersey.

Studies in various industries have found an association between worker exposure to lead and elevated blood lead levels in workers' children, but the magnitude of this problem is unknown. In an effort to characterize this problem further, a pilot study was undertaken to obtain blood lead levels of children of lead-exposed workers with elevated blood lead levels who had been reported by laboratories to the New Jersey Department of Health. Fifteen workers' families participated in this study, including 28 children. Thirty-two percent of the children were found to have blood lead levels > or = 10 micrograms/dl, the level of concern set by the Centers for Disease Control and Prevention for medical monitoring. This finding is in contrast to population-based data collected from the Third National Health and Nutrition Survey, where the overall prevalence of blood lead levels > or = 10 micrograms/dl was only 4.5%.

Adolescent↗
PubMed1995

Guidelines for application of meta-analysis in environmental epidemiology. ISLI Risk Science Institute.

The use of meta-analysis in environmental epidemiology can enhance the value of epidemiologic data in debates about environmental health risks. Meta-analysis may be particularly useful to formally examine sources of heterogeneity, to clarify the relationship between environmental exposures and health effects, and to generate information beyond that provided by individual studies or a narrative review. However, meta-analysis may not be useful when the relationship between exposure and disease is obvious, when there are only a few studies of the key health outcomes, or when there is substantial confounding or other biases which cannot be adjusted for in the analysis. Recent increases in the use of meta-analysis in environmental epidemiology have highlighted the need for guidelines for the application of the technique. Guidelines, in the form of desirable and undesirable attributes, are presented in this paper for various components of a meta-analysis including study identification and selection; data extraction and analysis; and interpretation, presentation, and communication of results. Also discussed are the appropriateness of the use of meta-analysis in environmental health studies and when meta-analysis should or should not be used.

Environmental Exposure↗
PubMed1995

Health risk implications of magnetic field exposures.

Magnetic field exposures pose serious questions to the public. The science is not sufficiently clear or consistent to result in a consensus. Some scientists view the data as strongly suggestive and argue that if the association is true, the ubiquity of exposure may be resulting in a marked underestimation of the actual risk. Others argue that the inconsistencies in the data and the specific limitations of the studies suggest that there is no association and no reason for concern. The state of the science is such that a definitive resolution is unlikely in the next few years. In light of this uncertainty, I believe that the most prudent course of action is the prevention or limitation of exposure where feasible at limited cost and inconvenience. Be it at home or at work, prevention of exposure is simply good public health practice.

Environmental Exposure↗
PubMed1994

Environmental tobacco smoke and childhood asthma: comparing exposure metrics using probability plots.

This study demonstrates the use of probability plots for assessing exposure-disease relationships in case-control studies. We reanalyze data from a study of childhood asthma and exposure to environmental tobacco smoke, comparing alternative measures of smoking intensity. Previous analyses showed a higher mean urinary cotinine-to-creatinine ratio (CCR) in cases as compared with controls and a statistically significant odds ratio with exposure defined as 30 ng/mg CCR or higher. Using probability plots, we compare alternative exposure metrics and exposure cutpoints with respect to their ability to detect a statistically significant exposure-disease effect. A strong exposure-disease response is evident, overall, and the results are fairly robust to the choice of exposure cutpoint.

Adolescent↗
PubMed1993

Evaluating exposure cutpoint bias in epidemiologic studies of electric and magnetic fields.

Epidemiologists who study the association between exposure to electric or magnetic fields and adverse health outcomes often classify their subjects as "exposed" and "unexposed," and they report results based on an odds ratio. The exposure classification rule--or dichotomy rule--is typically based on a priori assumptions or arbitrary considerations. We show that results may vary substantially with selection of different cutpoints by which to dichotomize exposure. Further, interpretation and comparison of studies is dependent on the choice of cutpoint. We suggest the use of probability plots as a more informative method of data representation. To demonstrate the utility of probability plots, we re-analyze data reported by Savitz et al. [1988, Am J Epidemiol 128:21-38]. Using a higher exposure cutpoint than that of the original analysis, we obtained larger odds ratios, two of which achieved statistical significance. More important, probability plots of these data showed 1) consistency of results with measures of magnetic fields in both low- and high-power-use situations, and 2) discordance with results based on measures of electric fields. Given these observations, we recommend further study, especially that focused on the most highly exposed individuals.

Bias↗
PubMed1993

Solving the cluster puzzle: clues to follow and pitfalls to avoid.

Dozens of methods have been proposed for the identification of disease clusters, although only a few are used routinely in published investigations. New methods, although designed to exploit some particular aspect of the data or use some specific statistical tool, are rarely compared thoroughly in terms of power or performance. Users, when confronted with the multitude of methods available, often select methods arbitrarily, basing choices on software availability, ease of implementation, or use experience rather than considerations of statistical power, possible alternative hypotheses (that is, cluster structure) and likely confounding. In this review, we extend our typology of disease clustering methods and apply it to many of the extant methods identifying strengths, weaknesses and unique features of the methods. We conclude with recommendations for which methods should be applied to which types of situations.

Cluster Analysis↗
PubMed1993

Identification and characterization of populations living near high-voltage transmission lines: a pilot study.

Populations living close to high-voltage transmission lines often have residential magnetic field exposures in excess of 1 microT, and sometimes over 2 microT. Yet, populations studied in most epidemiologic investigations of the association between residential magnetic field exposure and cancer typically have exposures below 1 microT and frequently below 0.5 microT. To improve statistical power and precision, it would be useful to compare high exposure populations with low exposure populations rather than only studying small differences within low exposure populations. Toward this end, we have developed an automated method for identifying populations living near high-voltage transmission lines. These populations likely have more highly exposed individuals than the population at large. The method uses a geographic information system (GIS) to superimpose digitized transmission line locations on U.S. Census block location data and then extract relevant demographic data. Analysis of data from a pilot study of the populations residing within 100 m of a 29-km segment of one 230-kV line in New Jersey shows that when compared to populations in the surrounding census blocks farther than 100 m from this line, those populations close to the line have similar demographics but differ in terms of perceived housing value variables. We believe that the approach we have developed will enable investigators to rapidly identify and characterize populations living near high-voltage transmission lines on a statewide basis for considering the impact of exposures and for public policy and that these populations also can be used for epidemiologic study.

Demography↗
PubMed1993

Human immunotoxicologic markers of chemical exposures: preliminary validation studies.

The circulating cells of the immune system are sensitive to environmental contaminants, and effects are often manifested as changes in the cell surface differentiation antigens of affected populations of cells, particularly lymphocytes. In this investigation, we explore the likelihood that variation in the expression of the surface markers of immune cells can be used as an index of exposure to toxic chemicals. We recruited 38 healthy New Jersey men to study pesticides effects: 19 orchard farmers (high exposure); 13 berry farmers (low exposure); and 6 hardware store owners (no exposure). Immunophenotyping was performed assaying the following cell surface antigens: CD2, CD4, CD8, CD14, CD20, CD26, CD29, CD45R, CD56, and PMN. Data were analyzed using univariate and multivariate methods. There were no significant differences among the groups with respect to routine medical histories, physical examinations, or routine laboratory parameters. No striking differences between groups were seen in univariate tests. Multivariate tests suggested some differences among groups and limited ability to correctly classify individuals based on immunophenotyping results. Immunophenotyping represents a fruitful area of research for improved exposure classification. Work is needed both on mechanistic understanding of the patterns observed and on the statistical interpretation of these patterns.

Agriculture↗
PubMed1992

Methodological problems in investigating disease clusters.

Increased reporting of disease clusters is stretching health department resources while failing to uncover many significant environmental hazards. By reviewing the methodology by which health departments respond to such reports, we argue that there is a strong bias against investigating the most hazardous situations. Failure to find serious hazards is more a reflection of the methodology used than an assessment of the existence of environmental problems. The biases arise from the selection of situations that dictate full in-house consideration, the selection of the methodology used to evaluate reported or registry-based data, and the interpretation given to anomalous observations. We argue for more rigorous evaluation of statistical cluster detection methods and for use of more objective criteria in cluster investigation protocols.

Disease Outbreaks↗
PubMed1992

Screening for lead exposure using a geographic information system.

Screening programs for lead overexposure typically target high-risk populations by identifying regions with common risk markers (older housing, poverty, etc.). While more useful than untargeted screening programs, targeted programs are limited by the geographic resolution of the risk-factor information. A geographic information system can make screening programs more effective and more cost-efficient by mapping cases of overexposure, identifying high-incidence neighborhoods warranting screening, and validating risk-factor-based prediction rules.

Child↗
PubMed1992

Risk to groundlings of death due to airplane accidents: a risk communication tool.

During the period 1975-85 in the United States the 70 year lifetime risk of dying from being hit by an airplane when the individual is on the ground was 4.2 per million people. In contrast to many other risks used for comparison purposes, risk to those on the ground from an airplane crash is not a function of our own skills; is not optional; provides no benefit to anyone involved; and is not an act of nature. As a risk comparison tool it also has the useful characteristics of being something about which we can agree that regulatory action, such as control of airplane use and traffic, is warranted; but that no significant change in personal behavior, such as living in the basement to protect against dying from a plane hitting the home, is commensurate with the extent of risk.

Accidents, Aviation↗