To advance and promote the discipline and professional practice of epidemiology in Ontario public health units
Please click here to visit our new website











 

 

 

2C Proximity to Community Focal Point

Description | Specific Indicators | Ontario Public Health Standards (OPHS) Corresponding Health Indicator(s) from Statistics Canada and CIHI Corresponding Indicator(s) from Other SourcesData Source(s) | Alternative Data Source(s)Survey Questions | Analysis Check List | Method of Calculation | Basic Categories | Indicator Comments | Definitions | Cross-References to Other Indicators | Cited References | Other References | Changes Made | Acknowledgements

 

Description
  • Proportion of the population within a 5 -10 minute (400-800m) walking distance to various community focal points i.e. green space, schools, neighbourhood food retailers, etc.
Specific Indicators
  • Proximity to a green space (includes park, public playground)
  • Proximity to a School 
    • Elementary school
    • Secondary School
  • Proximity to a neighbourhood food retailer

Please note that the above 3 mentioned are not the only indicators that can be calculated. This Core Indicator can relate to any focal point in the community.

 

Ontario Public Health Standards

The Ontario Public Health Standards (OPHS) establish requirements for the fundamental public health programs and services carried out by boards of health, which include assessment and surveillance, health promotion and policy development, disease and injury prevention, and health protection. The OPHS consist of one Foundational Standard and 13 Program Standards that articulate broad societal goals that result from the activities undertaken by boards of health and many others, including community partners, non-governmental organizations, and governmental bodies. These results have been expressed in terms of two levels of outcomes: societal outcomes and board of health outcomes. Societal outcomes entail changes in health status, organizations, systems, norms, policies, environments, and practices and result from the work of many sectors of society, including boards of health, for the improvement of the overall health of the population. Board of health outcomes are the results of endeavours by boards of health and often focus on changes in awareness, knowledge, attitudes, skills, practices, environments, and policies. Boards of health are accountable for these outcomes. The standards also outline the requirements that boards of health must implement to achieve the stated results.

 

Outcomes Related to this Indicator
  • Board of Health Outcome (Chronic Disease Prevention): There is increased awareness among community partners about the factors associated with chronic diseases that are required to inform program planning and policy development, including the following: the importance of creating healthy environments.
Health Promotion and Policy Development Requirement Related to this Indicator  
  • The board of health shall work with municipalities to support healthy public policies and the creation or enhancement of supportive environments in recreational settings and the built environment...
Assessment and Surveillance Requirements Related to this Indicator
  • Board of Health Outcome (Foundational Standard): The board of health shall conduct surveillance, including the ongoing collection, collation, analysis, and periodic reporting of population health indicators, as required by the Health Protection and Promotion Act and in accordance with the Population Health Assessment and Surveillance Protocol, 2008 (or as current, which includes population health data and information pertaining to physical environmental factors).

http://www.ontario.ca/publichealthstandards

 

Corresponding Health Indicator(s) from Statistics Canada and CIHI
  •  None
Corresponding Indicator(s) from Other Sources
  • Proportion of households within 1/2 mile of a public elementary school (1)

Data Sources

Spatial Datasets (Line) necessary for background calculations:

Roads Data (Ontario Road Network - ORN) (2)
Original Source: Ministry of Natural Resources
Distributed by: Ministry of Natural Resources
Metadata URL: http://publicdocs.mnr.gov.on.ca/View.asp?Document_ID=17566&Attachment_ID=37853 
Use: Generation of network dataset - used in part for the creation of the service areas (walking catchment areas)


Road Network File (RNF) (3)
Original Source: Statistics Canada, 2005-2010.
Distributed By: Statistics Canada
Metadata URL: http://www.statcan.gc.ca/bsolc/olc-cel/olc-cel?lang=eng&catno=92-500-GWE 
Use: Generation of network dataset - used in part for the creation of the service areas (walking catchment areas)
Suggested Citation: Road Network File, Census [year]. Statistics Canada Catalogue [no.].


Local Single-Line Road Network File (SLRN)
Original Source:
(Local Agency, Government)
Distributed By: (Local Agency, Government)
Metadata URL: (Local Agency, Government)
Use: Generation of network dataset - used in part for the creation of the service areas (walking catchment areas)


Layer (e.g. schools in this case - but could be any point source of interest such as libraries, grocery stores, etc.)
Original Source(s): Ministry of Education? DMTI? Local Municipalities? School Boards? MOE Source: http://www.edu.gov.on.ca/eng/sift/indexSec.asp 
Distributed by: Depends on the source(s)
Use: Used as the point source (facility) from where to start walking (for walking catchment area creation)
Spatial Datasets (Polygon): necessary for indicator calculation

 

Spatial Datasets (polygon) necessary for indicator calculations: 

 

Dissemination Areas (DAs)(or other Census Geographies containing population profile data) (4)
Original Source: Statistics Canada
Distributed by: Statistics Canada
Metadata: http://www.statcan.gc.ca/bsolc/olc-cel/olc-cel?lang=eng&catno=92-169-X
Use: Creation of population densities and proportional population densities within walking catchment areas.
Suggested Citation: Geography Division, Statistics Canada, Boundary Files, boundary file ID [no.], Census [year]

Walking Catchment Areas (polygons)
Source: Generated within the GIS in predetermined time intervals (e.g. 5 minutes, 10 minutes)
Use: To determine the area a pedestrian could cover in the set period of time and for intersections with population geographies (i.e. DAs) to generate proportional population densities. 

 

Alternative Data Source(s)(see Resources: Data Sources)

Numerator & Denominator: Rapid Risk Factor Surveillance System (RRFSS)
Original source: Public Health Units
Distributed by: Public Health Units
Suggested citation (see Data Citation Notes): RRFSS [month, year - month, year], Extracted: [month,year]

Survey Questions 

Data Source

Module

Question

Response Categories

Year

Community Focal Point

Variable

RRFSS

Urban Development Module 1: Importance of Walking Distance from Home

How important would it be to have each of the following within a 10 min walk or 1km of your home? (Schools)

1 very important

2 somewhat important

3 not very important

4 not at all important

8 don't know

9 refused

2010 

2009

(optional content)

Parks, trails and open green spaces

Urbw_1

Grocery stores

Urbw_2

Schools

Urbw_7


Analysis Check List

Roads Data (Ontario Road Network - ORN) Ministry of Natural Resources

  • Two data classes are available (ORN Net Element and ORN Segment with Address). The use of ORN Segment with Address is recommended for geo-coding and mapping applications (http://publicdocs.mnr.gov.on.ca/View.asp?Document_ID=17566&Attachment_ID=37853).  ORN Net Element can also be used with geographic coordinates (2). Other details of the datasets include:
    • ORN Segment with Address (Suggested). It includes: official street names, alternate street names, route names and numbers, street address ranges, road class, direction and municipality. 
    • ORN Road Net Element : Elements are identified by a measurement along a linear segment (Linear Reference System -LRS). It includes: official street names, alternate street names, street address ranges, road class, direction, municipality, blocked passage, toll point, junction, direction, jurisdiction, structure, road surface, route names and numbers, number of lanes and speed limit.  
  • When releasing or publishing the data, it is recommended to indicate the following characteristics of the road network:
    • Roads included are limited to those wide enough for two vehicles to safely pass and those with a street name, civic addresses, posted road name or number. Ferry connections are also included (2).
    • Proposed roads, roads under construction and roads under seasonal repair are not included.  Blocked passages (permanent or removable) are included (2).
    • The database does not contain information for northern communities isolated from the rest of the Ontario's road network (approx. 50-51 degrees north latitude) (see http://publicdocs.mnr.gov.on.ca/View.asp?Document_ID=17566&Attachment_ID=37853)
  • Sidewalks, trails and paths are not included in the ORN (see indicators comments for more details). The Ontario Trail Network could offer complementary information, but its scope tends to be limited to recreational trails (see http://publicdocs.mnr.gov.on.ca/View.asp?Document_ID=17567&Attachment_ID=37854).   When the information is available, sidewalks, trails and paths should be included when the information is available. Otherwise, clearly state that they are not included when the results are reported.
  • The database is updated on a monthly basis and it contains provincial, regional and municipal level information. Its position accuracy is +/- 10 m (see: http://publicdocs.mnr.gov.on.ca/View.asp?Document_ID=17566&Attachment_ID=37853)

 

Method of Calculation
  • The purpose of this indicator is to determine the number of people, as a population density, who are within a 5 to 10 minute walk (i.e. approximately 400 - 800 metres) of a community focal point. As this is largely a location-based operation, the use of Geographic Information system (GIS) is critical for reasonable estimations.
  • Two key datasets are necessary to make the calculations and determine the population density within a walking distance using GIS: a road network and population geography. The road network is the pathway by which one would walk. The population geography is the underlying administrative layer (i.e. census geographies) that contains population data (i.e. total population, density etc.).
  • The method of calculation for this indicator has two components:
    • Calculation of an area around a community focal point (e.g. a school) in which one could walk in a set period of time
    • Calculation of the population density within these calculated walking areas
  • Populations are reported for set administrative boundaries and roads. However, an individual's route of travel may not necessarily follow these boundaries. Therefore, to more accurately estimate population density within these calculated walking catchment areas, proportional population densities must be calculated, assuming the population is evenly distributed within the administrative boundary.
  • The idea of a catchment area indicator is to determine the population density within a set walking time of 5 and 10 minutes (and therefore distance at a set velocity) of a community focal point. On average a person walking at a comfortable pace can cover a distance of 400-800 meters in 5 to 10 minutes time.
  • It is assumed that the analyst performing the calculation for this indicator is familiar with the ESRI suite of tools (5), including ArcMap and the ArcGIS Network Analyst extension. The calculations discussed within this document can also be performed using other software packages (such as MapInfo) but the processes and terminology may differ.
  • One must first calculate the walking catchment area(s) around the community focal point of interest, which uses the road network as a route of travel. Once the catchment area(s) have been calculated, these polygon areas will intersect with Census Dissemination Areas (DAs) (or other polygon geographies that contain population information) to ultimately determine the population and area within this walking area, thereby allowing for the calculation of a population density.
  • The goal is to get a total population and a total area to properly calculate the density. Please see attached map for an example of 5 and 10 minute catchment area boundaries around schools. The map also includes the roads network dataset, school locations, and Census Dissemination Area (DA) boundaries.
Time it takes to walk a fixed road segment distance (in minutes) assuming a velocity of 4.8 km/hr:

distance (length) of road segment (in metres)

x 60 minutes

4800 metres




Population Density within walking catchment area "X" (in persons /sq. km):

*proportional population within walking catchment area "X"

 

**geographic area of walking catchment area "X" (in sq. km)


  * Note: this may be a sum of populations within multiple different geographic areas (i.e. dissemination areas)
** Note: this may be a sum of multiple geographic areas 

 

Basic Categories
  • Geographic areas: dissemination area (or any other census geography containing population data), service areas (i.e. calculated walking catchment area) around schools.
Indicator Comments
  • The manner in which the built environment impacts health outcomes is complex and varied, since human behaviour is influenced by multiple factors. The value of an individual indicator is strengthened when considered in combination with other built environment indicators. A range of built environment indicators, such as population density, proximity to community focal point, land use mix and job density, can be used to better appreciate the relationships among the built environment, health outcomes and health behaviours within your region.
  • To calculate walking catchment (e.g. Service Areas when using ESRI) areas in ArcGIS, the Network Analyst extension is required.  To improve accuracy and usability, sidewalks and trails/paths should be incorporated into the network to aid in generating the walking catchment areas, since pedestrians are not limited to walking only on roads and often take the shortest route available.  In addition, roads that are off-limits to pedestrians (i.e. 400 series highways) should be excluded from the network analysis.
  • Generating service areas (i.e. Catchment areas) within ArcGIS worked best when a new field (PedTimeMin) was added to the Roads layer, which was calculated to contain the time in minutes it would take to walk the length of the road.  The velocity must be set during the calculation.  A velocity of 4.8 km/hr was used in testing scenarios.  This newly added field was later used when performing the creation of walking catchment areas.
  • Population densities of the census geographies can be calculated, provided the area (sq. km) and population fields are populated.  This density can then be used to generate the number of people in the area that intersects the walking catchment area (acquired through an intersect operation, providing a proportional area). A homogeneous population distribution within the geography is assumed, but this may not always be the case as the census geographies are often larger than the walking distances.  Other methods of calculating populations are available but are not discussed in this document and should ultimately be chosen by the analyst performing the calculations. Running the summary statistics tool (particularly the SUM operation) in ArcGIS will help to calculate totals for each catchment area (CaseFields) to aid in calculating the population densities.
  • It is recommended to use dissemination areas (DA) or census sub-division (CSD) for level of geography as census tracts (CT) are mainly used in urban areas (4). However, dependent upon data availability and purpose of analysis, other levels of geography can also be used. 
  • Ideally, focal points such as schools or parks would be represented using polygons showing the area of the property.  Theoretically, buffers created within "x" metres from focal point could still fall within the property boundary, thereby limiting the number of DAs - and the population count - that fall within the boundary.  Having polygons represent specific focal point would allow for a proper buffer distance to be created so more accurate population counts could be calculated.It is recommended to use dissemination areas (DA) or census sub-division (CSD) for level of geography as census tracts (CT) are mainly used in urban areas (4). However, dependent upon data availability and purpose of analysis, other levels of geography can also be used.
  • When examining built environment Core Indicators, select the same geographic area of analysis to ensure that the indicators can be used in conjunction with each other.
Definitions
  • Green space: includes parks and public playgrounds; excludes school playgrounds.
  • Fresh Food Supplier: Supplier that regularly offers fresh foods with a selection of fruits, vegetables, dairy, and meat.
  • Walking Distance: 400m-800m is about a 5-10 minute walk
Cross References to Other Indicators
Cited References
  1. San Francisco Department of Public Health: The Healthy Development Measurement Tool. Available from: http://www.thehdmt.org/master_list.php (accessed June 2, 2010).  
  2. Government of Ontario. Ontario Road Network (ORN) Data Standard, 2009. Version 2.0. Available from: http://www.mgs.gov.on.ca/stdprodconsume/groups/content/@mgs/@goits/documents/resourcelist/stel02_047435.pdf (accessed on July 4, 2012)
  3. Statistics Canada. Road Network File. 2005-2010 Census. Statistics Canada Catalogue no. 92-500-XWE. April 29, 2010. Available from: http://www.statcan.gc.ca/bsolc/olc-cel/olc-cel?lang=eng&catno=92-169-X (accessed November 8th, 2011).
  4. Statistics Canada. Dissemination Area Cartographic Boundary File. 2006 Census. Statistics Canada Catalogue no. 92-169-XWE. February 14, 2007. Availble from: http://www.statcan.gc.ca/bsolc/olc-cel/olc-cel?lang=eng&catno=92-169-X (accessed November 8th, 2011).
  5. ESRI (12/17/2010). ArcGIS Documentation: Service Area Analysis. Available from: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Service_area_analysis/004700000048000000/ (accessed November 8th, 2011).
Other References
  1. Association of Public Health Epidemiologists of Ontario (APHEO). The Built Environment Resources. Available from: http://www.apheo.ca/index.php?pid=107. (accessed November 8th, 2011).
  2. ArcGIS Resource Centre. Creating a multimodal network dataset. (Network Analyst extension tutorial, containing valuable information to help generate the network dataset and service areas). Available from:
    http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Exercise_2_Creating_a_multimodal_network_dataset/00470000005v000000/. (accessed November 8th, 2011).
  3. Landex A, Hansen S. Examining the potential catchment areas for public transport. Available from: http://proceedings.esri.com/library/userconf/proc06/papers/papers/pap_1391.pdf (Similar methodologies used).(accessed November 8th, 2011).
  4. Leitner, S. GIS in Water Resources: Understanding Background Data to Aid in Corridor Planning. (Uses old ArcView program). Available from: http://www.crwr.utexas.edu/gis/gishydro01/class/trmproj/Leitner/termproject.html#Topic 2. (accessed November 8th, 2011).  
  5. Walk Score. Smart Street Walk Score. 2012. Available from: http://www.walkscore.com/professional/street-smart.php.
  6. Duany A, Sorlien S, Wright W.  Smart Code: Version 9 and Manual. Ithaca, NY: New Urban News Publications; 2008.
Changes Made
 

Date

Formal Review or Ad Hoc?

Changes made by

Changes

Created December 2011

New Indicator

 

 


Acknowledgements
 

Lead Authors 

  • Fabio Carbarcas, Halton Region Public Health
  • Steve Johnson, Public Health Ontario
  • Ahalya Mahendra, Public Health Agency of Canada
  • Deborah Moore, Niagara Region Public Health

Contributing Authors

  • Built Environment Subgroup

Reviewers

  • Paul Belanger, Kingston Frontenac Lennox and Addington Public Health
  • Mary-Anne Pietrusiak, Durham Region Health Department (Core Indicators Work Group Member)
  • David Stinton, Incite Planning and Lakeland District representative of the OPPI Recognition Committee
  • Megan Williams, Simcoe Muskoka District Health Unit

 

Treasurer/Secretary | Admin | Members Login

BrickHost