GIS in Health and Crime Analysis

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GIS in Health and Crime Analysis

The Role of GIS in Health and Crime is fairly obvious!

What is currently MISSING are many serious attempts to use GIS for the ANALYSIS of Health and Crime Databases

So an alternative title for this talk is..

A brief account of how to do some useful Spatial Analysis in GIS using Health and Crime Data as examples BUT without a single equation

Why would you want to analyse Health and Crime Data? Why ruin a perfectly good GIS with a spotless record of sparkling multicoloured mappings by also expecting it to do SPATIAL ANALYSIS as well as everything else?

The answer is simply...

the problem is that...

Most GISes are not very (or ANY) good at Spatial Analysis!

Mapping is not ANALYSIS!!

Ah!.. Well maybe we should keep quite about this Spatial Analysis deficiency. Sounds rather too academic for us practitioners. Also as no one does it (since they cannot) therefore no one probably wants it anyway!

Enter Joe Blogs..“Excuse me.. are you saying that you collect data that you do not fully analyse which I pay for?

“How!!If you are not doing analysis HOW DO YOU KNOW what is going on? I might die prematurely because of you or have my car stolen and wrecked because of your ignorance and your failure to do your job properly!”

I exaggerate to make a point!

Spatial Analysis Crime..

Lets have a closer look at Police IT!

A Home Office Consultative paper “Getting to Grips with Crime” Sept 1997

According to a survey of Local Authorities in England and Wales in July 1996 , some 62% undertook local Crime Pattern Analysis!

Lets look at Health IT

So WHY is there so little spatial analysis?

GIS needs spatial analysis methods that are exploratory

What happens if you have no hypothesis to test?

A category of REAL Spatial Analysis needs are essentially anomalous pattern detection

Spatial Analysis is also SPECIAL because unlike much of GIS there was little pre-GIS spatial analysis activity and hence the cost-benefit analysis is harder to perform

GIS has created a need for Spatial Analysis as a spin-off of its success! The vendors do not know how to cope with these needs and the users are deprived of relevant technology and have to try and make do the best they can.

Yet drawing Maps is not a very good idea

The need is for automated geographical analysis machines that read data, perform some analysis, and then tell you about it in a readily understood way

Mark 1 Geographical Analysis Machine

How does GAM work?

Geographical Analysis Machine (GAM) Mark 1 history

10 years ago GAM/1 was a mixed blessing!

GAM/1: good aspects

Some of the problems went away

But GAM was no longer being developed until...

International Agency for Research on Cancer (IARC)

Results published in Alexander and Boyle (1996)

Overall Performance when Detecting Clustering

Estimated Positive Sensitivities in Finding CLUSTER locations

Alexander and Boyle (1996) authors of the IARC study concluded:

That was in 1991!!!!!!!!

Algorithm was re-programmed from scratch

Making GAM/K run faster

Example 1. Burglary Data for somewhere in Northern England

Example 2. Applying GAM to the Long Term Limiting Illness data from 1991 census for Northern England

Map of Ward Level LLTI

Where are the localised areas of excess?

Disease Hot Spots

GAM/K is a descriptive tool

But aren’t the results so self evident that merely mapping the data would be enough and a blind man with a walking stick couldn’t have helped but noticed them?

Ward LLTI Map and GAM

Well you PUT YOUR GEOGRAPHER’S head back on and start to relate the clusters to the underlying map patterns!

Clusters of Deficiency

Teeside mapped with DoE’s Deprivation Score

Tyneside, DoE Deprivation

A Geographical Explanation Machine will hunt out the map associations for you!

A Geographical Explanations Machine- GEM/1

GEM can be run in 4 modes

Insufficient time to describe how GEM works instead we present some results using as pseudo coverages

Which clusters cannot be “explained” away?

Unexplained clusters on Tyneside

Clusters that can be “explained away”

Further Info: Email

Author: Stan Openshaw, University of Leeds

Email: stan@geog.leeds.ac.uk

Home Page: http://www.geog.leeds.ac.uk/staff/s.openshaw/