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Train related accidents, particularly derailments, can lead to severe consequences especially when they involve injuries or fatalities or when they involve hazardous materials that might result in environmental impacts. Whereas numerous road safety studies have suggested appropriate approaches to predicting vehicle-to-vehicle collisions, very few railway safety studies have considered predicting the number of derailments on rail tracks in North America. In addition, the existing few rail safety assessment and derailment prediction models have often been constrained by aggregated data limiting the safety assessments by, for example, failing to consider segment-level characteristics. This paper focused on the development of an integrated database for the development of a segment-level derailment prediction model for Canada’s rail network. The primary objective of this paper is to report how challenges in the data integration process were overcome and also to develop a network screening tool to identify segments with high derailment risk in Canada's rail network. Negative binomial regression and the Empirical Bayes technique were used to estimate the predicted number of derailments on Canada’s rail network at the segment level. A network screening process was then successfully applied to identify key segments of safety concern: the top ten segments of concern accounted for approximately 1% of the rail network allowing decision makers to focus their derailment mitigation efforts on a manageable part of Canada’s vast rail network. The data processing approach and analysis in this study have strong implications for advancing research on rail safety in North America.
Tavia Chow; Tayyab Ikram Shah; Peter Y. Park; Liping Fu. A GIS approach to the development of a segment-level derailment prediction model. Accident Analysis & Prevention 2021, 151, 105897 .
AMA StyleTavia Chow, Tayyab Ikram Shah, Peter Y. Park, Liping Fu. A GIS approach to the development of a segment-level derailment prediction model. Accident Analysis & Prevention. 2021; 151 ():105897.
Chicago/Turabian StyleTavia Chow; Tayyab Ikram Shah; Peter Y. Park; Liping Fu. 2021. "A GIS approach to the development of a segment-level derailment prediction model." Accident Analysis & Prevention 151, no. : 105897.
This research investigates the distribution of optometrists in Canada relative to population health needs and self-reported use of vision services. Optometrist locations were gathered from provincial regulatory bodies. Optometrist-to-population ratios (i.e. the number of providers per 10,000 people at the health region level) were then calculated. Utilization of vision care services was extracted from the Canadian Community Health Survey (CCHS) 2013–2014 question regarding self-reported contacts with optometrists or ophthalmologists. Data from the 2016 Statistics Canada census were used to create three population ‘need’ subgroups (65 years and over; low-income; and people aged 15 and over with less than a high school diploma). Cross-classification mapping compared optometrist distribution to self-reported use of vision care services in relation to need. Each variable was converted into three classes (i.e., low, moderate, and high) using a standard deviation (SD) classification scheme where ±0.5SD from the mean was considered as a cut-off. Three classes: low (< − 0.5SD), moderate (− 0.5 to 0.5SD), and high (> 0.5SD) were used for demonstrating distribution of each variable across health regions. A total of 5959 optometrists across ten Canadian provinces were included in this analysis. The nationwide distribution of optometrists is variable across Canada; they are predominantly concentrated in urban areas. The national mean ratio of optometrists was 1.70 optometrists per 10,000 people (range = 0.13 to 2.92). Out of 109 health regions (HRs), 26 were classified as low ratios, 51 HRs were classified as moderate ratios, and 32 HRs were high ratios. Thirty-five HRs were classified as low utilization, 39 HRs were classified as moderate, and 32 HRs as high utilization. HRs with a low optometrist ratio relative to eye care utilization and a high proportion of key sociodemographic characteristics (e.g. older age, low income) are located throughout Canada and identified with maps indicating areas of likely greater need for optometry services. This research provides a nationwide overview of vision care provided by optometrists identifying gaps in geographic availability relative to “supply” and “need” factors. This examination of variation in accessibility to optometric services will be useful to inform workforce planning and policies.
Tayyab Shah; Stephan Milosavljevic; Brenna Bath. Geographic availability to optometry services across Canada: mapping distribution, need and self-reported use. BMC Health Services Research 2020, 20, 1 -12.
AMA StyleTayyab Shah, Stephan Milosavljevic, Brenna Bath. Geographic availability to optometry services across Canada: mapping distribution, need and self-reported use. BMC Health Services Research. 2020; 20 (1):1-12.
Chicago/Turabian StyleTayyab Shah; Stephan Milosavljevic; Brenna Bath. 2020. "Geographic availability to optometry services across Canada: mapping distribution, need and self-reported use." BMC Health Services Research 20, no. 1: 1-12.
Chronic back disorders (CBD) are a global health problem and the leading cause of years lived with disability. The present study aims to examine overall and specific trends in CBD in the Canadian population aged 18 to 65 years. Data from the Canadian Community Health Survey (CCHS), a cross-sectional study, from 2007 to 2014 (8 cycles) were used to calculate CBD prevalence across gender, age, geographical area (urban/rural and ten provinces and northern territories), and physical activity levels. CBD was defined in the CCHS as having back problems, excluding fibromyalgia and arthritis, which have lasted or are expected to last six months or more and that have been diagnosed by a health professional. Prevalence of CBD using survey weights and associated 95% confidence intervals (95% CI) were calculated yearly using balanced repeated replications technique. Trend tests were calculated using joinpoint regressions; ArcGIS software was used for mapping. Age-standardized CBD prevalence in 2007 and 2014 were 18.9% (95% CI = 18.4;19.5) and 17.8% (95% CI = 17.2,18.4), respectively. CBD prevalence was consistently higher in women, older age groups, rural dwellers, and people classified as inactive. Crude and age-standardized CBD prevalence decreased faster in people classified as physically active compared to those who were inactive (p < 0.006). Although CBD slightly decreased over time, no statistically significant trends were found overall or by gender, area of residence, province or level of physical activity. The prevalence of CBD remained consistently high in the province of Nova Scotia, and consistently low in the province of Quebec over the eight CCHS cycles. Despite prevention efforts, such as the Canadian back pain mass media campaign, CBD prevalence has remained stable between 2007 and 2014. Tailored prevention and management of CBD should consider gender, age, and geographical differences. Further longitudinal studies could elucidate the temporal relationship between potentially modifiable risk factors such as physical activity and CBD.
Adriana Angarita-Fonseca; Catherine Trask; Tayyab Shah; Brenna Bath. Stable prevalence of chronic back disorders across gender, age, residence, and physical activity in Canadian adults from 2007 to 2014. BMC Public Health 2019, 19, 1 -11.
AMA StyleAdriana Angarita-Fonseca, Catherine Trask, Tayyab Shah, Brenna Bath. Stable prevalence of chronic back disorders across gender, age, residence, and physical activity in Canadian adults from 2007 to 2014. BMC Public Health. 2019; 19 (1):1-11.
Chicago/Turabian StyleAdriana Angarita-Fonseca; Catherine Trask; Tayyab Shah; Brenna Bath. 2019. "Stable prevalence of chronic back disorders across gender, age, residence, and physical activity in Canadian adults from 2007 to 2014." BMC Public Health 19, no. 1: 1-11.
Scott Bell; Michaela Sidloski; Tayyab Ikram Shah. Mapping the spatial pattern of the uncertain data in urban areas: The disadvantaged predict global nonresponse rate in the National Household Survey. The Canadian Geographer / Le Géographe canadien 2019, 64, 79 -104.
AMA StyleScott Bell, Michaela Sidloski, Tayyab Ikram Shah. Mapping the spatial pattern of the uncertain data in urban areas: The disadvantaged predict global nonresponse rate in the National Household Survey. The Canadian Geographer / Le Géographe canadien. 2019; 64 (1):79-104.
Chicago/Turabian StyleScott Bell; Michaela Sidloski; Tayyab Ikram Shah. 2019. "Mapping the spatial pattern of the uncertain data in urban areas: The disadvantaged predict global nonresponse rate in the National Household Survey." The Canadian Geographer / Le Géographe canadien 64, no. 1: 79-104.
Tayyab I. Shah; Andrew F. Clark; Jamie A. Seabrook; Shannon Sibbald; Jason A. Gilliland. Geographic accessibility to primary care providers: Comparing rural and urban areas in Southwestern Ontario. The Canadian Geographer / Le Géographe canadien 2019, 64, 65 -78.
AMA StyleTayyab I. Shah, Andrew F. Clark, Jamie A. Seabrook, Shannon Sibbald, Jason A. Gilliland. Geographic accessibility to primary care providers: Comparing rural and urban areas in Southwestern Ontario. The Canadian Geographer / Le Géographe canadien. 2019; 64 (1):65-78.
Chicago/Turabian StyleTayyab I. Shah; Andrew F. Clark; Jamie A. Seabrook; Shannon Sibbald; Jason A. Gilliland. 2019. "Geographic accessibility to primary care providers: Comparing rural and urban areas in Southwestern Ontario." The Canadian Geographer / Le Géographe canadien 64, no. 1: 65-78.
Urban cyclists are exposed to many traffic-related air pollutants including particulate matter (PM) that may increase vulnerability to health effects. This study investigates second-by-second personal exposure to PM2.5 (fine particulate matter that is 2.5 microns in diameter and less) along bicycle commuting paths, and assesses elements of the natural and built environment for the relative importance of these factors in understanding the variability in PM2.5 personal exposure. Urban cyclists were carrying high resolution PM2.5 monitors (placed in a backpack) in combination with portable GPS trackers to provide a spatial identity to each one-second pollutant measurement. The results of this study indicate that daily averages of PM2.5 concentrations from all bicycle routes were weakly correlated with meteorological variables, however, a strong influence of regional levels of PM2.5 was observed. Geospatial analysis of PM2.5 personal exposure concentrations showed a considerable variation within routes, correlated with land use (with lower concentrations in parks and higher in industrial areas) and clustered at four areas: busiest bridge, heavily trafficked road segments, the downtown urban core, and two construction sites. This study has found many incidences of personal exposure to PM2.5 exceeding the provincial guidelines for healthy activity (e.g., very poor (PM2.5 > 91 μg/m3) pollution concentrations are clustered in three regions: approaching the bridge in the west part of the city; the downtown urban core; and two under construction spots), which suggests behavioural and infrastructure modifications in balancing the health benefits of cycling with the environmental exposure to air pollutants.
Jason Gilliland; Matthew Maltby; Xiaohong Xu; Isaac Luginaah; Tayyab Shah. Influence of the Natural and Built Environment on Personal Exposure to Fine Particulate Matter (PM2.5) in Cyclists Using City Designated Bicycle Routes. Urban Science 2018, 2, 120 .
AMA StyleJason Gilliland, Matthew Maltby, Xiaohong Xu, Isaac Luginaah, Tayyab Shah. Influence of the Natural and Built Environment on Personal Exposure to Fine Particulate Matter (PM2.5) in Cyclists Using City Designated Bicycle Routes. Urban Science. 2018; 2 (4):120.
Chicago/Turabian StyleJason Gilliland; Matthew Maltby; Xiaohong Xu; Isaac Luginaah; Tayyab Shah. 2018. "Influence of the Natural and Built Environment on Personal Exposure to Fine Particulate Matter (PM2.5) in Cyclists Using City Designated Bicycle Routes." Urban Science 2, no. 4: 120.
Urban parks and open spaces offer a unique setting that can play a vital role in improving health and quality of life in cities and towns, making cities more attractive places to live and work, and connecting residents to nature. Degradation of park facilities caused by natural processes or recreational activities requires continuous monitoring for efficient maintenance and management. Identification and continuous monitoring of areas prone to natural hazards such as landslides within an urban park are particularly important for public safety. Traditional techniques for identification and monitoring of such areas involving field surveys, being costly and time-consuming, cannot be used on a regular basis. This research explored the integrated use of aerial photographs and point cloud LiDAR data for identification of areas prone to landslide and soil erosion zones in an urban park and a conservation area known as Wakamow Valley, Moose Jaw, Saskatchewan, Canada. This study used the point cloud LiDAR of 2014 to develop a Digital Elevation Model (DEM) of the area. The accuracy of the DEM was validated through a series of well-distributed ground control points collected through a survey grade handheld GPS device. The areas prone to potential landslides and soil erosion were identified using slope analysis techniques. A typical criterion of areas having a slope greater than 35° was used for classification of potential hazardous zones. Geospatial information including land-cover, land-use, and trail system was extracted from a 2014 aerial photograph to create a base map. It has been estimated that 5.3 km along the banks of the Moose Jaw River and 8 km along the cliff of the canyon-shaped Wakamow Valley are under a possible threat of soil erosion and landslides. This portion of the valley was classified as high-risk for possible landslides and soil erosion.
Abdul Raouf; Yulu Peng; Tayyab Ikram Shah. Integrated Use of Aerial Photographs and LiDAR Images for Landslide and Soil Erosion Analysis: A Case Study of Wakamow Valley, Moose Jaw, Canada. Urban Science 2017, 1, 20 .
AMA StyleAbdul Raouf, Yulu Peng, Tayyab Ikram Shah. Integrated Use of Aerial Photographs and LiDAR Images for Landslide and Soil Erosion Analysis: A Case Study of Wakamow Valley, Moose Jaw, Canada. Urban Science. 2017; 1 (2):20.
Chicago/Turabian StyleAbdul Raouf; Yulu Peng; Tayyab Ikram Shah. 2017. "Integrated Use of Aerial Photographs and LiDAR Images for Landslide and Soil Erosion Analysis: A Case Study of Wakamow Valley, Moose Jaw, Canada." Urban Science 1, no. 2: 20.
Urban environments can influence many aspects of health and well-being and access to health care is one of them. Access to primary health care (PHC) in urban settings is a pressing research and policy issue in Canada. Most research on access to healthcare is focused on national and provincial levels in Canada; there is a need to advance current understanding to local scales such as neighbourhoods. This study examines spatial accessibility to family physicians using the Three-Step Floating Catchment Area (3SFCA) method to identify neighbourhoods with poor geographical access to PHC services and their spatial patterning across 14 Canadian urban settings. An index of spatial access to PHC services, representing an accessibility score (physicians-per-1000 population), was calculated for neighborhoods using a 3km road network distance. Information about primary health care providers (this definition does not include mobile services such as health buses or nurse practitioners or less distributed services such as emergency rooms) used in this research was gathered from publicly available and routinely updated sources (i.e. provincial colleges of physicians and surgeons). An integrated geocoding approach was used to establish PHC locations. The results found that the three methods, Simple Ratio, Neighbourhood Simple Ratio, and 3SFCA that produce City level access scores are positively correlated with each other. Comparative analyses were performed both within and across urban settings to examine disparities in distributions of PHC services. It is found that neighbourhoods with poor accessibility scores in the main urban settings across Canada have further disadvantages in relation to population high health care needs. The results of this study show substantial variations in geographical accessibility to PHC services both within and among urban areas. This research enhances our understanding of spatial accessibility to health care services at the neighbourhood level. In particular, the results show that the low access neighbourhoods tend to be clustered in the neighbourhoods at the urban periphery and immediately surrounding the downtown area.
Tayyab Ikram Shah; Scott Bell; Kathi Wilson. Spatial Accessibility to Health Care Services: Identifying under-Serviced Neighbourhoods in Canadian Urban Areas. PLOS ONE 2016, 11, e0168208 .
AMA StyleTayyab Ikram Shah, Scott Bell, Kathi Wilson. Spatial Accessibility to Health Care Services: Identifying under-Serviced Neighbourhoods in Canadian Urban Areas. PLOS ONE. 2016; 11 (12):e0168208.
Chicago/Turabian StyleTayyab Ikram Shah; Scott Bell; Kathi Wilson. 2016. "Spatial Accessibility to Health Care Services: Identifying under-Serviced Neighbourhoods in Canadian Urban Areas." PLOS ONE 11, no. 12: e0168208.
We examined location-related accessibility to healthy and unhealthy food sources for school going children in Saskatoon, Saskatchewan. We compared proximity to food sources from school sites and from small clusters of homes (i.e., dissemination blocks) as a proxy for home location. We found that (1) unhealthy food sources are more prevalent near schools in lower income than higher income neighbourhoods; (2) unhealthy compared to healthy food sources are more accessible from schools as well as from places of residence; and (3) while some characteristics of neighbourhood low socio-economic status are associated with less accessibility to healthy food sources, there is no consistent pattern of access. Greater access to unhealthy food sources from schools in low-income neighbourhoods is likely a reflection of the greater degree of commercialization. Our spatial examination provides a more nuanced understanding of accessibility through our approach of comparing place of residence and school access to food sources.
Rachel Engler-Stringer; Tayyab Shah; Scott Bell; Nazeem Muhajarine. Geographic access to healthy and unhealthy food sources for children in neighbourhoods and from elementary schools in a mid-sized Canadian city. Spatial and Spatio-temporal Epidemiology 2014, 11, 23 -32.
AMA StyleRachel Engler-Stringer, Tayyab Shah, Scott Bell, Nazeem Muhajarine. Geographic access to healthy and unhealthy food sources for children in neighbourhoods and from elementary schools in a mid-sized Canadian city. Spatial and Spatio-temporal Epidemiology. 2014; 11 ():23-32.
Chicago/Turabian StyleRachel Engler-Stringer; Tayyab Shah; Scott Bell; Nazeem Muhajarine. 2014. "Geographic access to healthy and unhealthy food sources for children in neighbourhoods and from elementary schools in a mid-sized Canadian city." Spatial and Spatio-temporal Epidemiology 11, no. : 23-32.
The process of geocoding, particularly the street address matching process, is a commonly used technique to obtain locational information for public health research. In health care accessibility research, geocoded locations of health care providers are an essential element for measuring potential access to health care. Our objective is to compare the geocoding match rates and positional variation of two geocoding procedures by using street network and postal code datasets to geocode primary health care services in 14 cities. The first procedure uses a manually built geocoding service using DMTI Spatial (DMTI) reference datasets while the second employs an online geocoding service provided as a built‐in tool in ArcGIS, with ESRI Tele Atlas reference datasets. Results for Tele Atlas postal code and DMTI multiple enhanced postal codes (MEP) reference datasets produce much higher match rates (99.4%; 98.0% respectively) than street reference datsasets; while results of Tele Atlas street dataset produce better match rates (96.5%) than the DMTI street dataset (90.0%). Geocoding methods using Tele Atlas and DMTI Street datasets produce more accurate locations than postal code and MEP reference datasets. Empirical comparison of the geocoding results based on manually built and online geocoding services highlight the need for integrated geocoding procedures for increasing match rates with reduced positional uncertainty.
Tayyab Ikram Shah; Scott Bell; Kathi Wilson. Geocoding for public health research: Empirical comparison of two geocoding services applied to Canadian cities. The Canadian Geographer/Le Géographe canadien 2014, 58, 400 -417.
AMA StyleTayyab Ikram Shah, Scott Bell, Kathi Wilson. Geocoding for public health research: Empirical comparison of two geocoding services applied to Canadian cities. The Canadian Geographer/Le Géographe canadien. 2014; 58 (4):400-417.
Chicago/Turabian StyleTayyab Ikram Shah; Scott Bell; Kathi Wilson. 2014. "Geocoding for public health research: Empirical comparison of two geocoding services applied to Canadian cities." The Canadian Geographer/Le Géographe canadien 58, no. 4: 400-417.
Tayyab Ikram Shah; Scott Bell. Exploring the intra-urban variations in the relationship among geographic accessibility to PHC services and socio-demographic factors. Proceedings of the Second ACM SIGSPATIAL International Workshop on Mobile Geographic Information Systems - MobiGIS '13 2013, 68 -76.
AMA StyleTayyab Ikram Shah, Scott Bell. Exploring the intra-urban variations in the relationship among geographic accessibility to PHC services and socio-demographic factors. Proceedings of the Second ACM SIGSPATIAL International Workshop on Mobile Geographic Information Systems - MobiGIS '13. 2013; ():68-76.
Chicago/Turabian StyleTayyab Ikram Shah; Scott Bell. 2013. "Exploring the intra-urban variations in the relationship among geographic accessibility to PHC services and socio-demographic factors." Proceedings of the Second ACM SIGSPATIAL International Workshop on Mobile Geographic Information Systems - MobiGIS '13 , no. : 68-76.
Accessibility to health services at the local or community level is an effective approach to measuring health care delivery in various constituencies in Canada and the United States. GIS and spatial methods play an important role in measuring potential access to health services. The Three-Step Floating Catchment Area (3SFCA) method is a GIS based procedure developed to calculate potential (spatial) accessibility as a ratio of primary health care (PHC) providers to the surrounding population in urban settings. This method uses PHC provider locations in textual/address format supplied by local, regional, or national health authorities. An automated geocoding procedure is normally used to convert such addresses to a pair of geographic coordinates. The accuracy of geocoding depends on the type of reference data and the amount of value-added effort applied. This research investigates the success and accuracy of six geocoding methods as well as how geocoding error affects the 3SFCA method. ArcGIS software is used for geocoding and spatial accessibility estimation. Results will focus on two implications of geocoding: (1) the success and accuracy of different automated and value-added geocoding; and (2) the implications of these geocoding methods for GIS-based methods that generalise results based on location data.
Scott Bell; Kathi Wilson; Tayyab Ikram Shah; Sarina Gersher; Tina Elliott. Investigating impacts of positional error on potential health care accessibility. Spatial and Spatio-temporal Epidemiology 2012, 3, 17 -29.
AMA StyleScott Bell, Kathi Wilson, Tayyab Ikram Shah, Sarina Gersher, Tina Elliott. Investigating impacts of positional error on potential health care accessibility. Spatial and Spatio-temporal Epidemiology. 2012; 3 (1):17-29.
Chicago/Turabian StyleScott Bell; Kathi Wilson; Tayyab Ikram Shah; Sarina Gersher; Tina Elliott. 2012. "Investigating impacts of positional error on potential health care accessibility." Spatial and Spatio-temporal Epidemiology 3, no. 1: 17-29.