Table 7.
Geographic information systems (GIS) variables used in International Physical Activity and Environment Study of Adolescents (IPEN Adolescent)
| GIS construct | Description | Calculation |
| Residential Density | ||
| Density | Net residential density | Dwelling unit count/land area of buffer in square kilometres (km2) |
| Intersection density | ||
| Density | Intersection density | Intersection count/land area of buffer (km2) |
| Public transit | ||
| Counts | Transportation count for all types of public transit | Transit counts (any type) |
| Density | Transportation density for all types of public transit | Transit counts (any type)/land area of buffer (km2) |
| Distance | Distance to nearest public transit of any type | Street network distance in metres |
| Parks | ||
| Counts | Number of parks contained within or intersected by buffer | Park count (any size of park) |
| Area | Park area contained within or intersected by buffer | Park area (any size of park) in metres |
| Density | Park density | Park count (any size)/land area of buffer (km2) |
| Distance | Distance to nearest park of any size | Street network distance in metres |
| Private recreation | ||
| Counts of parcels | Number of recreation land use parcels | Private/public recreation parcel counts |
| Density of parcels | Recreation parcel density | Private/public recreation parcel count/land area of buffer (km2) |
| Counts of facilities | Number of private recreation facilities | Private recreation facilities counts |
| Density of facilities | Private recreation facilities density | Private recreation facilities count/ land area of buffer (km2) |
| Distance to facility | Distance to nearest private recreation facility | Street network distance in metres |
| Land use mix | ||
| Parcel counts (three uses) | Number of commercial/retail, food and entertainment parcels | Commercial/retail, food and entertainment parcel counts |
| Ratio of parcels to dwelling counts (three uses) | Ratio of commercial/retail, food and entertainment parcels to the number of dwelling units | Commercial/retail, food and entertainment parcel counts/dwelling unit counts |
| Ratio of land area to residential land area (three uses) | Ratio of commercial/retail, food and entertainment land area to residential land area | Commercial/retail, food and entertainment land area/residential land area |
| Ratio of parcels to residential land area (three uses) | Ratio of commercial/retail, food, and entertainment parcels to commercial/retail, food, and entertainment land area | Commercial/retail, food and entertainment parcel counts/commercial/retail, food and entertainment land area |
| Parcel counts (four uses) | Number of commercial/retail, food, entertainment and office parcels | Commercial/retail, food, entertainment and office parcel counts |
| Ratio of parcels to dwelling counts (four uses) | Ratio of commercial/retail, food, entertainment and office parcels to the number of dwelling units | Commercial/retail, food, entertainment and office parcel count/dwelling unit counts |
| Ratio of land area to residential land area (four uses) | Ratio of commercial/retail, food, entertainment and office land area to residential land area | Commercial/retail, food, entertainment and office land area/residential land area |
| Ratio of parcels to residential land area (four uses) | Ratio of commercial/retail, food, entertainment and office parcels to commercial/retail, food, entertainment and office land area | Commercial/retail, food, entertainment and office parcel counts/ commercial/retail, food, entertainment and office land area |
| Parcel counts (five uses) | Number of commercial/retail, food, entertainment, office, and civic parcels | Commercial/retail, food, entertainment, office and civic parcel counts |
| Ratio of parcels to dwelling counts (five uses) | Ratio of commercial/retail, food, entertainment, office, and civic parcels to the number of dwelling units | Commercial/retail, food, entertainment, office and civic parcel counts/dwelling unit counts |
| Ratio of land area to residential land area (five uses) | Ratio of commercial/retail, food, entertainment, office, and civic land area to residential land area | Commercial/retail, food, entertainment, office and civic land area/residential land area |
| Ratio of parcels to residential land area (five uses) | Ratio of commercial/retail, food, entertainment, office, and civic parcels to commercial/retail, food, entertainment, office, and civic land area | Commercial/retail, food, entertainment, office and civic parcel counts/commercial/retail, food, entertainment, office and civic land area |
| Regional accessibility | ||
| Distance | Distance to nearest downtown/centre city | Street network distance in metres |
| Distance | Distance to nearest major transit hub | Street network distance in metres |
| Distance | Distance to nearest to largest university | Street network distance in metres |
| Distance | Distance to nearest largest hospital | Street network distance in metres |
| Distance | Distance to nearest largest employment centre | Street network distance in metres |
| Distance | Distance to nearest largest natural/open space feature | Street network distance in metres |
| Distance | Distance to nearest major shopping centre | Street network distance in metres |
| Distance | Distance to nearest major employment centre | Street network distance in metres |
All variables calculated for four buffer sizes (250 m, 500 m, 1 km, and 2 km) and for residential and school buffers. For most variables, 500 m and 1 km buffer sizes are considered primary variables, and 250 m and 2 km buffer sizes are considered secondary variables. Fewer countries have the secondary variable so they will not be prioritised for most IPEN Adolescent papers. All variables calculated using street network buffers with the sausage buffer calculation method.