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

Potential accessibility, travel time, and consumer choice: Geographical variations in general medical practice registrations in Eastern England

The availability of choice is a neglected aspect in studies of geographical accessibility, which typically concentrate on distance to the nearest service. Records of patient registrations with general medical practices offer the opportunity to examine the geographical distribution of choice for an essential service. This population study of two million residents of Cambridgeshire, Norfolk, and Suffolk used postcodes extracted from patient registers and estimated car travel times from residential locations to general practice surgeries in a geographical information system. Only 56% of the population were registered with the practice nearest their home. People were more likely to use the nearest practice if they lived in rural rather than urban areas and where a surgery was within walking distance. Choice, as measured by the number of practices used by 95% of residents, was highest in the larger urban areas and lowest in small towns and rural areas with a local surgery. Ten percent of the population were served by monopoly practices. Overall, the distribution of registrations reflected a regular and predictable substitution of choice for increased travel time. People were 29% less likely to register with a practice for every additional minute of travel time: an almost perfect distance-decay relationship that was used to calibrate a potential model of accessibility over the study area. The resulting values of potential accessibility were found to approximate the combination of travel time to the nearest surgery and the actual range of choice exercised by residents. This demonstration that the potential accessibility model reflects consumer behaviour has applications beyond the health field