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Full-Text Articles in Public Health

Is The Closest Facility The One Actually Used? An Assessment Of Travel Time Estimation Based On Mammography Facilities, Jennifer Alford-Teaster, Jane M. Lange, Rebecca A. Hubbard, Christoph I. Lee, Jennifer S. Haas, Xun Shi, Heather A. Carlos, Louise Henderson, Deirdre Hill, Anna N. A. Tosteson, Tracy Onega Feb 2016

Is The Closest Facility The One Actually Used? An Assessment Of Travel Time Estimation Based On Mammography Facilities, Jennifer Alford-Teaster, Jane M. Lange, Rebecca A. Hubbard, Christoph I. Lee, Jennifer S. Haas, Xun Shi, Heather A. Carlos, Louise Henderson, Deirdre Hill, Anna N. A. Tosteson, Tracy Onega

Dartmouth Scholarship

Characterizing geographic access depends on a broad range of methods available to researchers and the healthcare context to which the method is applied. Globally, travel time is one frequently used measure of geographic access with known limitations associated with data availability. Specifically, due to lack of available utilization data, many travel time studies assume that patients use the closest facility. To examine this assumption, an example using mammography screening data, which is considered a geographically abundant health care service in the United States, is explored. This work makes an important methodological contribution to measuring access--which is a critical component of …


A Multiscale Mapping Assessment Of Lake Champlain Cyanobacterial Harmful Algal Blooms, Nathan Torbick, Megan Corbiere, Yu-Pin Lin Sep 2015

A Multiscale Mapping Assessment Of Lake Champlain Cyanobacterial Harmful Algal Blooms, Nathan Torbick, Megan Corbiere, Yu-Pin Lin

Dartmouth Scholarship

Lake Champlain has bays undergoing chronic cyanobacterial harmful algal blooms that pose a public health threat. Monitoring and assessment tools need to be developed to support risk decision making and to gain a thorough understanding of bloom scales and intensities. In this research application, Landsat 8 Operational Land Imager (OLI), Rapid Eye, and Proba Compact High Resolution Imaging Spectrometer (CHRIS) images were obtained while a corresponding field campaign collected in situ measurements of water quality. Models including empirical band ratio regressions were applied to map chlorophylla and phycocyanin concentrations; all sensors performed well with R² and root-mean-square error (RMSE) ranging …


Relationship Between Altitude And Lithium In Groundwater In The United States Of America: Results Of A 1992–2003 Study, Rebekah S. Huber, Namkug Kim, Carl E. Renshaw, Perry F. Renshaw, Douglas Kondo Jan 2014

Relationship Between Altitude And Lithium In Groundwater In The United States Of America: Results Of A 1992–2003 Study, Rebekah S. Huber, Namkug Kim, Carl E. Renshaw, Perry F. Renshaw, Douglas Kondo

Dartmouth Scholarship

Therapeutic dosages of lithium are known to reduce suicide rates, which has led to investigations of confounding environmental risk factors for suicide such as lithium in groundwater. It has been speculated that this might play a role in the potential relationship between suicide and altitude. A recent study in Austria involving geospatial analysis of lithium in groundwater and suicide found lower levels of lithium at higher altitudes. Since there is no reason to suspect this correlation is universal given variation in geology, the current study set out to investigate the relationship between altitude and lithium in groundwater in the United …


Mapping Disease At An Approximated Individual Level Using Aggregate Data: A Case Study Of Mapping New Hampshire Birth Defects, Xun Shi, Stephanie Miller, Kevin Mwenda, Akikazu Onda Sep 2013

Mapping Disease At An Approximated Individual Level Using Aggregate Data: A Case Study Of Mapping New Hampshire Birth Defects, Xun Shi, Stephanie Miller, Kevin Mwenda, Akikazu Onda

Dartmouth Scholarship

Limited by data availability, most disease maps in the literature are for relatively large and subjectively-defined areal units, which are subject to problems associated with polygon maps. High resolution maps based on objective spatial units are needed to more precisely detect associations between disease and environmental factors. Method: We propose to use a Restricted and Controlled Monte Carlo (RCMC) process to disaggregate polygon-level location data to achieve mapping aggregate data at an approximated individual level. RCMC assigns a random point location to a polygon-level location, in which the randomization is restricted by the polygon and controlled by the background (e.g., …


Smart Density: A More Accurate Method Of Measuring Rural Residential Density For Health-Related Research, Peter M. Owens, Linda Titus-Ernstoff, Lucinda Gibson, Michael L. Beach, Sandy Beauregard, Madeline A. Dalton Feb 2010

Smart Density: A More Accurate Method Of Measuring Rural Residential Density For Health-Related Research, Peter M. Owens, Linda Titus-Ernstoff, Lucinda Gibson, Michael L. Beach, Sandy Beauregard, Madeline A. Dalton

Dartmouth Scholarship

Studies involving the built environment have typically relied on US Census data to measure residential density. However, census geographic units are often unsuited to health-related research, especially in rural areas where development is clustered and discontinuous. We evaluated the accuracy of both standard census methods and alternative GIS-based methods to measure rural density.


Computing Travel Time When The Exact Address Is Unknown: A Comparison Of Point And Polygon Zip Code Approximation Methods, Ethan M. Berke, Xun Shi Jan 2009

Computing Travel Time When The Exact Address Is Unknown: A Comparison Of Point And Polygon Zip Code Approximation Methods, Ethan M. Berke, Xun Shi

Dartmouth Scholarship

Travel time is an important metric of geographic access to health care. We compared strategies of estimating travel times when only subject ZIP code data were available.Using simulated data from New Hampshire and Arizona, we estimated travel times to nearest cancer centers by using: 1) geometric centroid of ZIP code polygons as origins, 2) population centroids as origin, 3) service area rings around each cancer center, assigning subjects to rings by assuming they are evenly distributed within their ZIP code, 4) service area rings around each center, assuming the subjects follow the population distribution within the ZIP code. We used …


Using Built Environment Characteristics To Predict Walking For Exercise, Gina S. Lovasi, Anne V. Moudon, Amber L. Pearson, Philip M. Hurvitz, Eric B. Larson, David S. Siscovick, Ethan M. Berke Feb 2008

Using Built Environment Characteristics To Predict Walking For Exercise, Gina S. Lovasi, Anne V. Moudon, Amber L. Pearson, Philip M. Hurvitz, Eric B. Larson, David S. Siscovick, Ethan M. Berke

Dartmouth Scholarship

Environments conducive to walking may help people avoid sedentary lifestyles and associated diseases. Recent studies developed walkability models combining several built environment characteristics to optimally predict walking. Developing and testing such models with the same data could lead to overestimating one's ability to predict walking in an independent sample of the population. More accurate estimates of model fit can be obtained by splitting a single study population into training and validation sets (holdout approach) or through developing and evaluating models in different populations. We used these two approaches to test whether built environment characteristics near the home predict walking for …