Geomatics in injury prevention: the science, the potential and the limitations

Geospatial Mapping to Target Injury Prevention for Older Adult Ground-Level Falls: A Feasibility Study

BACKGROUND

Trauma centers target injury prevention efforts based on trauma registry and local epidemiological data. Identifying geographic patterns of injury through geospatial mapping has emerged as a technology to help identify at-risk individuals. Yet, the feasibility of using spatial analysis to target injury prevention efforts remains unknown.

OBJECTIVE

This study aims to demonstrate the use of geospatial mapping of older adult ground-level falls to target injury prevention efforts.

METHODS

This retrospective cohort analysis of ground-level falls among older adults was conducted from 2017 to 2020 at a Level I trauma center and safety net hospital. Trauma admissions, U.S. census median income, Hispanic percentage, and population density by zip codes were combined to create choropleth and heat maps to identify injury hot spots to target fall prevention classes.

RESULTS

A total of 5,629 patients were reviewed, of which 3,002 (53%) were fall cases. Low-level falls (<10 ft) accounted for 2,224 cases; 1,449 were among older adults centered around the study hospital. Ground-level falls accounted for 1,663 patients, of whom 1,182 were older adults clustering around senior housing, assisted living facilities, nursing homes, and rehabilitation centers. As a result, our fall prevention classes are now targeted at these newly identified locations.

CONCLUSION

Geospatial analysis provided powerful visualization of fall injury locations to target our fall prevention efforts. Geospatial analysis is a feasible tool for trauma centers to guide injury prevention strategies that effectively target the populations most in need.

Evaluation of a population health strategy to reduce distracted driving: Examining all "Es" of injury prevention

BACKGROUND

Cell phone use while driving (CPWD) increases the risk of crashing and is a major contributor to injuries and deaths. The objective of this study was to describe the evaluation of a multifaceted, evidence-based population health strategy for the reduction of distracted driving.

METHODS

A multipronged campaign was undertaken from 2014 to 2016 for 16- to 44-year-olds, based on epidemiology, focused on personal stories and consequences, using the "Es" of injury prevention (epidemiology, education, environment, enforcement, and evaluation). Education consisted of distracted driving videos, informational cards, a social media AdTube campaign, and a movie theater trailer, which were evaluated with a questionnaire regarding CPWD attitudes, opinions, and behaviors. Spatial analysis of data within a geographic information system was used to target advertisements. A random sample telephone survey evaluated public awareness of the campaign. Increased CPWD enforcement was undertaken by police services and evaluated by ARIMA time series modeling.

RESULTS

The AdTube campaign had a view rate of >10% (41,101 views), slightly higher for females. The top performing age group was 18- to 24-year-olds (49%). Our survey found 61% of respondents used handheld CPWD (14% all of the time) with 80% reporting our movie trailer made them think twice about future CPWD. A stakeholder survey and spatial analysis targeted our advertisements in areas of close proximity to high schools, universities, near intersections with previous motor vehicle collisions, high traffic volumes, and population density. A telephone survey revealed that 41% of the respondents were aware of our campaign, 17% from our print and movie theater ads and 3% from social media. Police enforcement campaign blitzes resulted in 160 tickets for CPWD. Following campaign implementation, there was a statistically significant mean decrease of 462 distracted driving citations annually (p = 0.001).

CONCLUSION

A multifaceted, evidence-based population health strategy using the Es of injury prevention with interdisciplinary collaboration is a comprehensive method to be used for the reduction of distracted driving.

LEVEL OF EVIDENCE

Therapeutic, level IV.

Does Land Use and Landscape Contribute to Self-Harm? A Sustainability Cities Framework

Self-harm has become one of the leading causes of mortality in developed countries. The overall rate for suicide in Canada is 11.3 per 100,000 according to Statistics Canada in 2015. Between 2000 and 2007 the lowest rates of suicide in Canada were in Ontario, one of the most urbanized regions in Canada. However, the interaction between land use, landscape and self-harm has not been significantly studied for urban cores. It is thus of relevance to understand the impacts of land-use and landscape on suicidal behavior. This paper takes a spatial analytical approach to assess the occurrence of self-harm along one of the densest urban cores in the country: Toronto. Individual self-harm data was gathered by the National Ambulatory Care System (NACRS) and geocoded into census tract divisions. Toronto’s urban landscape is quantified at spatial level through the calculation of its land use at different levels: (i) land use type, (ii) sprawl metrics relating to (a) dispersion and (b) sprawl/mix incidence; (iii) fragmentation metrics of (a) urban fragmentation and (b) density and (iv) demographics of (a) income and (b) age. A stepwise regression is built to understand the most influential factors leading to self-harm from this selection generating an explanatory model.

Spatial distribution of child pedestrian injuries along census tract boundaries: Implications for identifying area-based correlates

Census tracts are often used to investigate area-based correlates of a variety of health outcomes. This approach has been shown to be valuable in understanding the ways that health is shaped by place and to design appropriate interventions that account for community-level processes. Following this line of inquiry, it is common in the study of pedestrian injuries to aggregate the point level locations of these injuries to the census tracts in which they occur. Such aggregation enables investigation of the relationships between a range of socioeconomic variables and areas of notably high or low incidence. This study reports on the spatial distribution of child pedestrian injuries in a mid-sized U.S. city over a three-year period. Utilizing a combination of geospatial approaches, Near Analysis, Kernel Density Estimation, and Local Moran’s I, enables identification, visualization, and quantification of close proximity between incidents and tract boundaries. Specifically, results reveal that nearly half of the 100 incidents occur within roads that are also census tract boundaries. Results also uncover incidents that occur on tract boundaries, not merely near them. This geographic pattern raises the question of the utility of associating area-based census data from any one tract to the injuries occurring in these border zones. Furthermore, using a standard spatial join technique in a Geographic Information System (GIS), these points located on the border are counted as falling into census tracts on both sides of the boundary, which introduces uncertainty in any subsequent analysis. Therefore, two additional approaches of aggregating points to polygons were tested in this study. Results differ with each approach, but without any alert of such differences to the GIS user. This finding raises a fundamental concern about techniques through which points are aggregated to polygons in any study using point level incidents and their surrounding census tract socioeconomic data to understand health and place. This study concludes with a suggested protocol to test for this source of uncertainty in analysis and an approach that may remove it.

An overview of geospatial methods used in unintentional injury epidemiology

Background

Injuries are a leading cause of death and disability around the world. Injury incidence is often associated with socio-economic and physical environmental factors. The application of geospatial methods has been recognised as important to gain greater understanding of the complex nature of injury and the associated diverse range of geographically-diverse risk factors. Therefore, the aim of this paper is to provide an overview of geospatial methods applied in unintentional injury epidemiological studies.

Methods

Nine electronic databases were searched for papers published in 2000–2015, inclusive. Included were papers reporting unintentional injuries using geospatial methods for one or more categories of spatial epidemiological methods (mapping; clustering/cluster detection; and ecological analysis). Results describe the included injury cause categories, types of data and details relating to the applied geospatial methods.

Results

From over 6,000 articles, 67 studies met all inclusion criteria. The major categories of injury data reported with geospatial methods were road traffic (n = 36), falls (n = 11), burns (n = 9), drowning (n = 4), and others (n = 7). Grouped by categories, mapping was the most frequently used method, with 62 (93%) studies applying this approach independently or in conjunction with other geospatial methods. Clustering/cluster detection methods were less common, applied in 27 (40%) studies. Three studies (4%) applied spatial regression methods (one study using a conditional autoregressive model and two studies using geographically weighted regression) to examine the relationship between injury incidence (drowning, road deaths) with aggregated data in relation to explanatory factors (socio-economic and environmental).

Conclusion

The number of studies using geospatial methods to investigate unintentional injuries has increased over recent years. While the majority of studies have focused on road traffic injuries, other injury cause categories, particularly falls and burns, have also demonstrated the application of these methods. Geospatial investigations of injury have largely been limited to mapping of data to visualise spatial structures. Use of more sophisticated approaches will help to understand a broader range of spatial risk factors, which remain under-explored when using traditional epidemiological approaches.

Electronic supplementary material

The online version of this article (doi:10.1186/s40621-016-0097-0) contains supplementary material, which is available to authorized users.

An evidence-based method for targeting an abusive head trauma prevention media campaign and its evaluation

BACKGROUND

A triple-dose abusive head trauma (AHT) prevention program (Period of PURPLE Crying) was implemented. The third dose consisted of an education media campaign. The study objectives were to describe the qualitative and spatial methods developed to target AHT prevention and to evaluate this campaign.

METHODS

A questionnaire on the level of importance of factors, rated on a 7-point Likert scale, was distributed to a panel of experts to determine the best advertising locations. Ranked factors were used to create weights for statistical modeling and mapping within a Geographic Information Systems to determine optimal ad locations. The media campaign was evaluated via a telephone survey of randomly selected households.

RESULTS

The survey found locations of new families, high population density, and high percentage of lone parents to be the most important factors for selecting billboard sites. Spatial analysis revealed six areas that ranked highest in our factors. Five billboards, four media posters, and six transit shelters were selected for our advertisements. A population-based telephone survey revealed that 23% of respondents knew the campaign. Nearly half (42%) heard the radio public service announcements, and 9% saw billboards.

CONCLUSION

Extending primary prevention efforts to the public helps to create a cultural change in the way inconsolable crying, the trigger for AHT, is viewed. With the use of ranked factors and Geographic Information Systems, geographic locations with high visibility and specific risk factors for AHT were identified for targeting the campaign, facilitating the likelihood that our message was reaching the population in greatest need.

A comprehensive approach to pediatric injury prevention in the emergency department

Injury is the leading cause of pediatric mortality and long-term disability. Although the primary care setting has traditionally been considered as the main venue to address injury anticipatory guidance, an emergency department (ED) visit may serve as a "teachable moment" because most injured children are cared for in this setting and the experience may elicit a greater chance of behavior change. However, EDs can also provide additional information and services beyond counseling to prevent injuries. These adjunct efforts and activities focus on primary injury prevention (screening for and promoting safe behaviors and collecting data to survey high-risk community locations), secondary prevention (use of safety products to mitigate injury), and tertiary prevention (maximizing injury care and minimizing injury sequelae). This review will describe several ways an ED can help to mitigate the epidemic of pediatric injuries through surveillance, screening, education, product disbursement, community engagement, and quality improvement efforts.

Shaken baby syndrome and a triple-dose strategy for its prevention

OBJECTIVES

Inflicted traumatic brain injury associated with Shaken Baby Syndrome (SBS) is a leading cause of injury mortality and morbidity in infants. A triple-dose SBS prevention program was implemented with the aim to reduce the incidence of SBS. The objectives of this study were to describe the epidemiology of SBS, the triple-dose prevention program, and its evaluation.

METHODS

Descriptive and spatial epidemiologic profiles of SBS cases treated at Children's Hospital, London Health Sciences Centre, from 1991 to 2010 were created. Dose 1 (in-hospital education): pre-post impact evaluation of registered nurse training, with a questionnaire developed to assess parents' satisfaction with the program. Dose 2 (public health home visits): process evaluation of additional education given to new parents. Dose 3 (media campaign): a questionnaire developed to rate the importance of factors on a 7-point Likert scale. These factors were used to create weights for statistical modeling and mapping within a geographic information system to target prevention ads.

RESULTS

Forty-three percent of severe infant injuries were intentional. A total of 54 SBS cases were identified. The mean age was 6.7 months (standard deviation, 10.9 months), with 61% of infant males. The mean Injury Severity Score was 26.3 (standard deviation, 5.5) with a 19% mortality rate. Registered nurses learned new information on crying patterns and SBS, with a 47% increase in knowledge posttraining (p < 0.001). Over 10,000 parents were educated in-hospital, a 93% education compliance rate. Nearly all parents (93%) rated the program as useful, citing "what to do when the crying becomes frustrating" as the most important message. Only 6% of families needed to be educated during home visits. Locations of families with a new baby, high population density, and percentage of lone parents were found to be the most important factors for selecting media sites. The spatial analysis revealed six areas needed to be targeted for ad locations.

CONCLUSIONS

SBS is a devastating intentional injury that often results in poor outcomes for the child. Implementing a triple-dose prevention program that provides education on crying patterns, coping strategies, and the dangers of shaking is key to SBS prevention. The program increased knowledge. Parents rated the program as useful. The media campaign allowed us to extend the primary prevention beyond new parents to help create a cultural change in the way crying, the primary trigger for SBS, is viewed. Targeting our intervention increased the likelihood that our message was reaching the population in greatest need.

Targeting pediatric pedestrian injury prevention efforts: teasing the information through spatial analysis

BACKGROUND

Pediatric pedestrian injuries remain a major cause of childhood death, hospitalization, and disability. To target injury prevention efforts, it is imperative to identify those children at risk. Racial disparities have been noted in the rates of pediatric pedestrian injury and death. Children from low-income families living in dense, urban residential neighborhoods have a higher risk of sustaining pedestrian injury. Geographic information systems (GIS) analysis of associated community factors such as child population density and median income may offer insights into prevention.

METHODS

Using trauma registry E-codes for pedestrian motor vehicle crashes, children younger than 16 years were identified, who received acute care and were hospitalized at the University of Chicago Medical Center, a Level I pediatric trauma center, after being struck by a motor vehicle from 2002 to 2009. By retrospective chart review and review of the Emergency Medical Services run sheets, demographic data and details of the crash site were collected. Crash sites were aggregated on a block by block basis. A "hot spot" analysis was performed to localize clusters of injury events. Using Gi* statistical method, spatial clusters were identified at different confidence intervals using a fixed distance band of 400 m (≈ ¼ mile). Maps were generated using GIS with 2000 census data to evaluate race, employment, income, density of public and private schools, and density of children living in the neighborhoods surrounding our medical center where crash sites were identified. Spatial correlation is used to identify statistically significant locations.

RESULTS

There were 3,521 children admitted to the University of Chicago Medical Center for traumatic injuries from 2002 to 2009; 27.7% (974) of these children sustained injuries in pedestrian motor vehicle injuries. From 2002 to 2009, there were a total of 106 traumatic deaths, of which 29 (27.4%) were due to pedestrian motor vehicle crashes. Pediatric pedestrian motor vehicle crash sites occurred predominantly within low-income, predominantly African-American neighborhoods. A lower prevalence of crash sites was observed in the predominantly higher income, non-African-American neighborhoods.

CONCLUSIONS

Spatial analysis using GIS identified associations between pediatric pedestrian motor vehicle crash sites and the neighborhoods served by our pediatric trauma center. Pediatric pedestrian motor vehicle crash sites occurred predominantly within low-income, African-American neighborhoods. The disparity in prevalence of crash sites is somewhat attributable to the lower density of children living in the predominantly higher income, non-African-American neighborhoods, including the community immediately around our hospital. Traffic volume patterns, as a denominator of these injury events, remain to be studied.

Using geographical information systems mapping to identify areas presenting high risk for traumatic brain injury

BACKGROUND

The aim of this study is to show how geographical information systems (GIS) can be used to track and compare hospitalization rates for traumatic brain injury (TBI) over time and across a large geographical area using population based data.

RESULTS & DISCUSSION

Data on TBI hospitalizations, and geographic and demographic variables, came from the Ontario Trauma Registry Minimum Data Set for the fiscal years 1993-1994 and 2001-2002. Various visualization techniques, exploratory data analysis and spatial analysis were employed to map and analyze these data. Both the raw and standardized rates by age/gender of the geographical unit were studied. Data analyses revealed persistent high rates of hospitalization for TBI resulting from any injury mechanism between two time periods in specific geographic locations.

CONCLUSIONS

This study shows how geographic information systems can be successfully used to investigate hospitalizaton rates for traumatic brain injury using a range of tools and techniques; findings can be used for local planning of both injury prevention and post discharge services, including rehabilitation.

Collecting injury surveillance data in low- and middle-income countries: the Cape Town Trauma Registry pilot

Injury is a major public health issue, responsible for 5 million deaths each year, equivalent to the total mortality caused by HIV, malaria and tuberculosis combined. The World Health Organisation estimates that of the total worldwide deaths due to injury, more than 90% occur in low- and middle-income countries (LMIC). Despite the burden of injury sustained by LMIC, there are few continuing injury surveillance systems for collection and analysis of injury data. We describe a hospital-based trauma surveillance instrument for collection of a minimum data-set for calculating common injury scoring metrics including the Abbreviated Injury Scale and the Injury Severity Score. The Cape Town Trauma Registry (CTTR) is designed for injury surveillance in low-resource settings. A pilot at Groote Schuur Hospital in Cape Town was conducted for one month to demonstrate the feasibility of systematic data collection and analysis, and to explore challenges of implementing a trauma registry in a LMIC. Key characteristics of the CTTR include: ability to calculate injury severity, key minimal data elements, expansion to include quality indicators and minimal drain on human resources based on few fields. The CTTR provides a strategy to describe the distribution and consequences of injury in a high trauma volume, low-resource environment.

Trauma in the neighborhood: a geospatial analysis and assessment of social determinants of major injury in North America

OBJECTIVES

We sought to identify and characterize areas with high rates of major trauma events in 9 diverse cities and counties in the United States and Canada.

METHODS

We analyzed a prospective, population-based cohort of injured individuals evaluated by 163 emergency medical service agencies transporting patients to 177 hospitals across the study sites between December 2005 and April 2007. Locations of injuries were geocoded, aggregated by census tract, assessed for geospatial clustering, and matched to sociodemographic measures. Negative binomial models were used to evaluate population measures.

RESULTS

Emergency personnel evaluated 8786 major trauma patients, and data on 7326 of these patients were available for analysis. We identified 529 (13.7%) census tracts with a higher than expected incidence of major trauma events. In multivariable models, trauma events were associated with higher unemployment rates, larger percentages of non-White residents, smaller percentages of foreign-born residents, lower educational levels, smaller household sizes, younger age, and lower income levels.

CONCLUSIONS

Major trauma events tend to cluster in census tracts with distinct population characteristics, suggesting that social and contextual factors may play a role in the occurrence of significant injury events.

Analyzing the effects of place on injury: Does the choice of geographic scale and zone matter?

BACKGROUND

Recent studies have shown that the morbidity and mortality associated with injury of pedestrians are inversely related to socio-economic status (SES). However, in drawing inferences from this association, investigators have paid little attention to the modifiable artifacts related to scale and how the data are partitioned. The purpose of this population-based study was to identify the relation between SES and incidence patterns of pedestrian injury at 4 different geographic scales.

METHODS

We used a Poisson generalized linear model, stratified by age and sex, to analyze the relation between each of 4 area measures of SES and incidence patterns of pedestrian injuries occurring in metropolitan Vancouver between 1 January 2001 and 31 March 2006. The 4 area measures of SES were based on boundaries of dissemination areas, census tracts, custom-defined census tracts (generated by reassignment of dissemination area boundaries by means of a geographic information system) and census subdivisions of the Canadian census. We measured the SES of the location where the injury occurred with the Vancouver Area Neighbourhood Deprivation Index.

RESULTS

A total of 262 injuries in adults (18 years of age or older) were analyzed. Among adult men, the odds ratio (OR) for injury of pedestrians at the scale of dissemination area was 4.93 (95% confidence interval [CI] 2.89-8.42) for areas having the lowest SES relative to those with the highest SES. For the same population, the OR for injury was lower with increasing aggregation of data: 2.33 (95% CI 1.45-3.74) when census tracts were used, 3.26 (95% CI 2.06-5.16) when modified census tracts were used and 1.27 (95% CI 0.47-3.45) when census subdivisions were used. Among adult women, the OR for pedestrian injury by SES was highest at the scale of census subdivision within medium-low SES areas (4.33, 95% CI 1.23-15.22). At the census subdivision scale, the relation between SES and incidence pattern of injury was not consistent with findings at smaller geographic scales, and the OR for injury decreased with each increase in SES.

INTERPRETATION

In this analysis, there was significant variability when different administrative boundaries were applied as proxy measures of the effects of place on incidence patterns of injury. The hypothesized influence of SES on prevalence of pedestrian injury followed a statistically significant socio-economic gradient when analyzed using small-area boundaries of the census. However, researchers should be aware of the inherent variability that remains even among the more homogenous population units.

Geographic cluster analysis of injury severity and hospital resource use in a regional trauma system

OBJECTIVES

To determine clusters of trauma incidents with high injury severity and resource utilization and to test their association with census demographic information.

METHODS

Using "trauma band" unique identifiers and probabilistic linkage for unmatched cases, we matched injury location information collected from a centralized regional trauma communications center to the state trauma system registry for patients directly transported to two level I trauma centers for the years 2001-2003 in a three-county area. The injury locations were aggregated at the census tract level using a geographic information system (GIS). Moran's I analysis was used to determine clusters of census tracts that had a high incidence of either total trauma injuries, Injury Severity Scores (ISSs) >15, or high resource use (in-hospital mortality, admission to the intensive care unit, or major nonorthopedic surgery). These clusters were then tested for association with census tract demographics using logistic regression.

RESULTS

Eight thousand seven hundred fifty-one injured persons were directly transported from the tricounty area to a trauma center during the study period. The mean (+/- standard deviation) age was 37 +/- 21 years, 67.4% were male, 18.9% had ISSs >15, and 29.8% had a high-resource-use indicator. Moran's I analysis demonstrated a single large cluster of incidents for total injuries, ISS >15, and occurrence of a high-resource-use indictor that overlapped except for one small census tract. Logistic regression revealed that the high-risk cluster was associated with a higher prevalence of nonwhite population and vacant housing and a lower prevalence of foreign-born residents and family housing.

CONCLUSIONS

GIS cluster analysis demonstrated high-risk census tracts for trauma incidents and associated population demographics. Geospatial analyses may assist injury prevention interventions and emergency medical services deployment strategies for trauma.

Injury surveillance in low-resource settings using Geospatial and Social Web technologies

Background

Extensive public health gains have benefited high-income countries in recent decades, however, citizens of low and middle-income countries (LMIC) have largely not enjoyed the same advancements. This is in part due to the fact that public health data - the foundation for public health advances - are rarely collected in many LMIC. Injury data are particularly scarce in many low-resource settings, despite the huge associated burden of morbidity and mortality. Advances in freely-accessible and easy-to-use information and communication (ICT) technology may provide the impetus for increased public health data collection in settings with limited financial and personnel resources.

Methods and Results

A pilot study was conducted at a hospital in Cape Town, South Africa to assess the utility and feasibility of using free (non-licensed), and easy-to-use Social Web and GeoWeb tools for injury surveillance in low-resource settings. Data entry, geocoding, data exploration, and data visualization were successfully conducted using these technologies, including Google Spreadsheet, Mapalist, BatchGeocode, and Google Earth.

Conclusion

This study examined the potential for Social Web and GeoWeb technologies to contribute to public health data collection and analysis in low-resource settings through an injury surveillance pilot study conducted in Cape Town, South Africa. The success of this study illustrates the great potential for these technologies to be leveraged for public health surveillance in resource-constrained environments, given their ease-of-use and low-cost, and the sharing and collaboration capabilities they afford. The possibilities and potential limitations of these technologies are discussed in relation to the study, and to the field of public health in general.

Moving beyond traditional measurement of mortality after injury: evaluation of risks for late death

BACKGROUND

The purpose of this study was to evaluate long-term mortality after trauma, and to determine risk factors and possible disparities related to mortality after hospital discharge.

STUDY DESIGN

Level I trauma center registry data from a 6-year period (2000 through 2005) were linked to patient electronic medical records, the National Death Index with cause of death codes, and census data using geographic information science (GIS) methodologies. Census data provided supplemental demographic and socioeconomic information from patient neighborhoods.

RESULTS

The hospital mortality rate for 15,285 patients was 3.3%, and mortality after discharge was 4.8%. Overall mortality for the study period was 8.1% (average follow-up, 2.8 years, 1-year mortality, 5.4%). Mortality after discharge was related to the initial injury in 33%, possibly related in 23%, and unrelated in 44% of patients. Logistic regression analysis demonstrated that independent predictors of hospital mortality were age, Injury Severity Score, gunshot injury, significant head injury, fall, and spinal cord injury. In contrast, independent risk factors for mortality after discharge were age, hospital length of stay, discharge from the hospital to a locale other than home, and the presence of spinal cord injury. Intoxication at hospital admission and injury due to a gunshot wound or motor vehicle collision were protective for late mortality. Bivariate analysis of census data demonstrated that lower socioeconomic status was associated with improved hospital survival, and non-native status was associated with mortality after discharge.

CONCLUSIONS

There is significant mortality attributable to trauma for up to 1 year after hospital discharge. These findings suggest that mortality after trauma needs to be measured beyond hospital discharge in order to assess the complete impact of injury.

GIS and injury prevention and control: history, challenges, and opportunities

Intentional and unintentional injury is the leading cause of death and potential years of life lost in the first four decades of life in industrialized countries around the world. Despite surgical innovations and improved access to emergency care, research has shown that certain populations remain particularly vulnerable to the risks and consequences of injury. Recent evidence has shown that the analytical, data linkage, and mapping tools of geographic information systems (GIS) technology provide can further address these determinants and identify populations in need. This paper traces the history of injury prevention and discusses current and future challenges in furthering our understanding of the determinants of injury through the use of GIS.

Patterns of urban violent injury: a spatio-temporal analysis

Objectives

Injury related to violent acts is a problem in every society. Although some authors have examined the geography of violent crime, few have focused on the spatio-temporal patterns of violent injury and none have used an ambulance dataset to explore the spatial characteristics of injury. The purpose of this study was to describe the combined spatial and temporal characteristics of violent injury in a large urban centre.

Methodology/Principal Findings

Using a geomatics framework and geographic information systems software, we studied 4,587 ambulance dispatches and 10,693 emergency room admissions for violent injury occurrences among adults (aged 18–64) in Toronto, Canada, during 2002 and 2004, using population-based datasets. We created kernel density and choropleth maps for 24-hour periods and four-hour daily time periods and compared location of ambulance dispatches and patient residences with local land use and socioeconomic characteristics. We used multivariate regressions to control for confounding factors. We found the locations of violent injury and the residence locations of those injured were both closely related to each other and clearly clustered in certain parts of the city characterised by high numbers of bars, social housing units, and homeless shelters, as well as lower household incomes. The night and early morning showed a distinctive peak in injuries and a shift in the location of injuries to a “nightlife” district. The locational pattern of patient residences remained unchanged during those times.

Conclusions/Significance

Our results demonstrate that there is a distinctive spatio-temporal pattern in violent injury reflected in the ambulance data. People injured in this urban centre more commonly live in areas of social deprivation. During the day, locations of injury and locations of residences are similar. However, later at night, the injury location of highest density shifts to a “nightlife” district, whereas the residence locations of those most at risk of injury do not change.

Comparison of Poisson and Bernoulli spatial cluster analyses of pediatric injuries in a fire district

Background

With limited resources available, injury prevention efforts need to be targeted both geographically and to specific populations. As part of a pediatric injury prevention project, data was obtained on all pediatric medical and injury incidents in a fire district to evaluate geographical clustering of pediatric injuries. This will be the first step in attempting to prevent these injuries with specific interventions depending on locations and mechanisms.

Results

There were a total of 4803 incidents involving patients less than 15 years of age that the fire district responded to during 2001–2005 of which 1997 were categorized as injuries and 2806 as medical calls. The two cohorts (injured versus medical) differed in age distribution (7.7 ± 4.4 years versus 5.4 ± 4.8 years, p < 0.001) and location type of incident (school or church 12% versus 15%, multifamily residence 22% versus 13%, single family residence 51% versus 28%, sport, park or recreational facility 3% versus 8%, public building 8% versus 7%, and street or road 3% versus 30%, respectively, p < 0.001). Using the medical incident locations as controls, there was no significant clustering for environmental or assault injuries using the Bernoulli method while there were four significant clusters for all injury mechanisms combined, 13 clusters for motor vehicle collisions, one for falls, and two for pedestrian or bicycle injuries. Using the Poisson cluster method on incidence rates by census tract identified four clusters for all injuries, three for motor vehicle collisions, four for fall injuries, and one each for environmental and assault injuries. The two detection methods shared a minority of overlapping geographical clusters.

Conclusion

Significant clustering occurs overall for all injury mechanisms combined and for each mechanism depending on the cluster detection method used. There was some overlap in geographic clusters identified by both methods. The Bernoulli method allows more focused cluster mapping and evaluation since it directly uses location data. Once clusters are found, interventions can be targeted to specific geographic locations, location types, ages of victims, and mechanisms of injury.