Biomedical subjects

F Benjamin Zhan

Publications and source records attributed to F Benjamin Zhan.

6 recordsLinked to original sources

PubMed2006

Match rate and positional accuracy of two geocoding methods for epidemiologic research.

PURPOSE: This study compares the match rate and positional accuracy of two geocoding methods: the popular geocoding tool in ArcGIS 9.1 and the Centrus GeoCoder for ArcGIS. METHODS: We first geocoded 11,016 Texas addresses in a case-control study using both methods and obtained the match rate of each method. We then randomly selected 200 addresses from those geocoded by using both methods and obtained geographic coordinates of the 200 addresses by using a global positioning system (GPS) device. Of the 200 addresses, 110 were case maternal residence addresses and 90 were control maternal residence addresses. These GPS-surveyed coordinates were used as the "true" coordinates to calculate positional errors of geocoded locations. We used Wilcoxon signed rank test to evaluate whether differences in positional errors from the two methods were statistically significantly different from zero. In addition, we calculated the sensitivity and specificity of the two methods for classifying maternal addresses within 1500 m of toxic release inventory facilities when distance is used as a proxy of exposure. RESULTS: The match rate of the Centrus GeoCoder was more than 10% greater than that of the geocoding tool in ArcGIS 9.1. Positional errors with the Centrus GeoCoder were less than those of the geocoding tool in ArcGIS 9.1, and this difference was statistically significant. Sensitivity and specificity of the two methods are similar. CONCLUSIONS: Centrus GeoCoder for ArcGIS for geocoding gives greater match rates than the geocoding tool in ArcGIS 9.1. Although the Centrus GeoCoder has better positional accuracy, both methods give similar results in classifying maternal addresses within 1500 m of toxic release inventory facilities when distance is used as a proxy of exposure.

Databases as Topic↗

PubMed2006

GIS-EpiLink: a spatial search tool for linking environmental and health data.

One inherent characteristic of both environmental data and health data is that they have a location component. This characteristic makes Geographic Information Systems (GIS) an ideal and sometimes indispensable tool for analyzing environmental and health data. Indeed, the past decade witnessed significant efforts in developing GIS tools for supporting epidemiologic research. Despite these efforts, the availability of accessible GIS tools that can be easily used by epidemiologists to link environmental and health data has remained a problem. We present a simple spatial search tool--GIS-EpiLink--that can be used to link environmental and health data when distance between an environmental site and the location of the maternal address of a case or control is used as a proxy for exposure. The tool was used in a research project and it successfully provided the necessary data for epidemiological analyses. This tool should be very useful to epidemiologists in environmental health research.

Environmental Exposure↗

PubMed2006

Maternal residential proximity to waste sites and industrial facilities and oral clefts in offspring.

OBJECTIVE: This study examined the association between oral clefts and maternal residential proximity to waste sites or industries. METHODS: In a case-control study, maternal residences at birth of 1781 births with oral clefts and 4368 comparison births were related to locations of waste sites and industrial facilities in Texas through geographic information systems. RESULTS: Compared with women who lived farther, women who lived within a mile of these sites or facilities were not more likely to have offspring with oral clefts. Among women > or =35 years, oral clefts in offspring were associated with living within a mile of industrial facilities (odds ratio [OR] = 2.4, 95% confidence interval [CI] = 1.3-4.2), especially smelters (OR = 15.0, 95% CI = 2.8-151). CONCLUSION: These findings suggest that maternal residential proximity to industries might be associated with oral clefts in births to older mothers.

Case-Control Studies↗

PubMed2003

Geographic patterns of cancer mortality clusters in Texas, 1990 to 1997.

Geographic patterns of cancer mortality can often provide clues for public health professionals to identify high-risk areas where limited resources can be directed to conduct cancer epidemiological studies or improve health services related to cancer prevention and treatment. From spatial cluster analyses of mortality cases from 16 specific cancers in Texas over the period from 1990 to 1997, geographic patterns of cancer mortality clusters in Texas were identified. The results suggest that Texas citizens would benefit if cancer epidemiology studies and cancer prevention and treatment practices in Texas would target counties in Southeast Texas for mortality related to lung and bronchial cancer, female breast cancer, colon cancer, and non-Hodgkin's lymphoma; target counties in East (particularly Northeast) Texas for mortality from lung and bronchial cancer, pancreatic cancer, cancer of the brain and other nervous systems, and liver cancer; examine colon cancer mortality in Kaufman County; pay particular attention to mortality from liver cancer in San Antonio and the counties south of San Antonio; direct extra efforts to prostate cancer in the Dallas-Fort Worth area; and investigate the unusually high mortality rate of cervical cancer in Crockett County.

Cluster Analysis↗

PubMed2002

Are deaths from liver cancer, kidney cancer, and leukemia clustered in San Antonio?

High mortality rates per square mile associated with liver cancer, lung cancer, kidney cancer, and leukemia have been reported in San Antonio. Without taking into account the underlying at-risk population, cancer mortality rates per square mile alone may give the public a misleading picture. This study conducts a geographic cluster analysis of mortality of the four types of cancer mentioned above, considering both mortality cases and the at-risk population. The analysis uses statewide cancer mortality data over an 8-year period from 1990 through 1997. Results from the study indicate that only one statistically significant cluster of liver cancer mortality cases exists in Bexar County and its adjacent counties compared with the rest of Texas. No clusters of lung cancer, kidney cancer, or leukemia exist in San Antonio.

Humans↗

PubMedDate not supplied

Linking environmental hazards and birth defects data.

The authors describe methods for linking birth certificate and birth defect registry data to potential environmental hazards and assess potential confounding factors. Cases of selected birth defects from the Texas Birth Defects Registry were linked to their respective birth/ fetal death records. Comparison births were randomly selected from the 1996-2000 Texas birth records. Maternal addresses were related through a geographic information system to boundaries of hazardous waste sites and point locations of industries. Approximately 89% of maternal addresses of case births and 88% of comparison births were successfully related in distance to these sites and industries. Maternal characteristics associated with living within one mile of these sites included belonging to any group besides non-Hispanic white and having lower education attainment (< 16 years) or a residence within the city limits. In linking environmental and health outcome databases, researchers should be aware of factors that may confound associations between exposure and outcomes.

Adult↗