A geospatial analysis of the relationship between neighbourhood socioeconomic status and adult severe injury in Greater Vancouver

Abstract

Background: Every year, injuries cost the Canadian healthcare system billions of dollars and result in thousands of emergency room visits, hospitalisations and deaths. The purpose of this study was to explore the relationship between neighbourhood socioeconomic status (NSES) and the rates of all-cause, unintentional and intentional severe injury in Greater Vancouver adults. A second objective was to determine whether the identified associations were spatially consistent or non-stationary.

Methods: Severe injury cases occurring between 2001 and 2006 were identified using the British Columbia's Coroner's Service records and the British Columbia Trauma Registry, and mapped by census dissemination areas using a geographical information system. Descriptive statistics and exploratory spatial data analysis methods were used to gain a better understanding of the data sets and to explore the relationship between the rates of severe injury and two measures of NSES (social and material deprivation). Ordinary least squares and geographically weighted regression were used to model these relationships at the global and local levels.

Results: Inverse relationships were identified between both measures of NSES and the rates of severe injury with the strongest associations located in Greater Vancouver's most socioeconomically deprived neighbourhoods. Social deprivation was found to have a slightly stronger relationship with the rates of severe injury than material deprivation.

Conclusions: Results of this study suggest that policies and programmes aimed at reducing the burden of severe injury in Greater Vancouver should take into account social and material deprivation, and should target the most socioeconomically deprived neighbourhoods in Greater Vancouver.

Figure 1

Maps of social deprivation, material deprivation, and social and material deprivation (c) in Greater Vancouver. These maps show the spatial distribution of social deprivation, material deprivation, and social and material deprivation across Greater Vancouver. Each census dissemination area is symbolised based on their quintile rank, with light green and light blue depicting neighbourhoods in the least deprived quintile (Q1) and dark green and dark blue depicting neighbourhoods in the most deprived quintile (Q5). In the map at the top of the figure, only the neighbourhoods that are in the least deprived quintile of both indices (Q1–Q1) and in the most deprived quintile of both indices (Q5–Q5) are highlighted. As shown, there is very little overlap between the spatial distribution of social and material deprivation in Greater Vancouver.

Figure 2

Crude annual incident rates of all-cause severe injury by neighbourhood socio-economic status (NSES) quintiles. The crude annual incidence rate of all-cause severe injury is given for each social and material deprivation quintile. Neighbourhoods in the least deprived social and material deprivation quintiles (Q1-Q1) are also compared with the neighbourhoods in the most deprived social and material deprivation quintiles (Q5-Q5). The dark bars correspond with the least deprived quintiles (Q1) and with the most deprived quintiles (Q5).

Figure 3

Clusters of high (HH) and low (LL) rates, unintentional and intentional severe injury. These maps show spatial clusters of high (HH) and low (LL) rates of unintentional and intentional severe injury in Greater Vancouver.

Figure 4

Association between all-cause severe injury and social deprivation. This map shows where the relationship between the incidence rate of all-cause severe injury and social deprivation is the strongest and the weakest. The map also identifies the neighbourhoods where there were clusters of high all-cause severe injury rates and social deprivation coefficient values. In other words, it depicts specific regions within our study area where policies and programmes aimed at reducing the rates of all-cause severe injury by augmenting the social environment would have the greatest benefit.