How Data Should be Restructured: Population Catchment Approach

Respect for the principles articulated in the previous section leads to new opportunities for designing new systems. The following assumptions, and consequent data strategies, outline the ways this may be actualized:

1. The population catchment is geographically defined by proximity to the point-of-care. In urban areas, health facilities are central, easily accessible, and numerous to accommodate dense populations. Individuals living in urban settings often have several options for health facilities within close proximity and may select their location of care based on other factors, such as wait times or specialty, rather than simply proximity. In comparison, rural communities in BC are typically served by a single health centre or hospital with most of the population situated relatively close by the health facility. This is because rural regions in BC are composed of distinct population clusters between mountains and dense forest patches. Due to this isolated and dispersed geography, BC is well suited to be organized into distinct geographically defined population-based catchments surrounding each rural health service point. Rural provides a unique opportunity for the creation of distinct catchments and the ability to examine their effectiveness.
2. One hour of travel time to a care centre is a reasonable distance to work with as a standard measure since there is recognition of this standard travel time in the literature related to rural maternity care and trauma care outcomes.^10,11 Ultimately, however, this limit is arbitrary.
3. The population of the catchment, based on residency, is definable through address, including using postal codes.
4. Health service utilization data for the defined population is the first layer of outcomes and can be related to the quality of local services. It is likely that some residents of rural catchments will travel further away to access basic services for family or personal reasons, but the majority of residents should access care based on location unless there are significant barriers such as racism, inequity, or quality of care issues. If utilization patterns are unusual in the catchment then further analysis might be justified.
5. Population catchments can be linked to health outcomes through BC health data resources like Population Data BC and Perinatal Services BC using the home address of patients.
6. The definition of a population denominator within the catchment framework provides a tool for comparison between rural communities. The establishment of a level playing field based on population and the need for services creates the potential for evidence-based systematic planning and quality improvement. This is particularly relevant to a time of system renewal and transformation such as we are currently experiencing across the province.

The RHSRNbc has created a GIS Catchment Tool mapping areas located a one-hour drive time from the the local health facility, ultimately forming the catchment boundary. This map demonstrates the catchment map for Fort St James, a northern community in BC (Figure 2).

The next step is to link this map to postal codes which will act as a way of defining the resident population (Figure 3).

The postal codes and map can be linked to census data through the census tracts. These data can include specific demographic factors such as a population age distribution (Figure 4) and proportion of catchment population that is Indigenous (Figure 5) in order to better plan and provide health services.

Census data can be tracked back through previous census collections to create longitudinal population tracking:

Overall, data can be organized into a community profile that can be created for each community in BC. The data are also considered relatively stable as census updates occur every 5 years. The community profile can include a list and map of local services as shown in the map of Fort St James below:

A map can also be attached that shows the relationship of the community with the nearest referral centre:

As a result, this process records the population residing within a one-hour drive of the health centre or hospital in question. The GIS Catchment Tool will link health services or interventions with health outcomes through isolated groupings of people in rural communities, enabling us to develop and assess new healthcare models. Furthermore, these catchments will help to determine the proportion of the BC population that is not accessing healthcare services. 

Models like these have applicability for a wide variety of healthcare policy and planning. Establishing a catchment profile for each community in the province, and ensuring that it is updated based on availability of external data, can be a tool to aid in ecosystem disruption planning. Developing projections and scenario-based analyses for disruptions like the COVID-19 pandemic can better equip rural communities to respond effectively, particularly when they have access to community-specific and relevant data.