UNDERSTANDING SPATIAL DISTRIBUTION OF ASTHMA USING

A GEOGRAPHICAL INFORMATION SYSTEM

Mohammad A. RobManagement Information Systems

University of Houston-Clear Lake

Contents

• Introduction

• Geographic Information System (GIS)

• Asthma Epidemic: An Example

• Applications of GIS in Spatial Distribution of Asthma

• Business Geography: A New Discipline

• Conclusion

Introduction

• Geographic Information System (GIS) is used to make strategic decisions when data have spatial (geographical) distribution

• Government agencies use it for assessment and planning in areas such as housing, healthcare, land use, transportation, and environmental monitoring

• Businesses use it to locate optimum retail location and delivery route

Introduction

• Current corporate databases do not contain geospatial reference

• However, GIS tools can be used to add geographical coordinates to existing data

• Thus existing data can be presented on a map and make strategic decisions

• Major database vendors (Microsoft, IBM, Oracle, Informix) are adding a “spatial” data type to their enterprise database systems

Introduction

• The use of GIS tools require more knowledge of information technology than geography

• GIS datasets are already available through the Web

• Most organizations perform GIS analysis without getting involved with the mapping technology

• There are GIS technicians, analysts, programmers, and managers

Introduction

• Soon there will be GIS specialists like IT specialists in every organization

• Many IT specialists will become GIS specialists

• We discuss the basic principles and functionality of a GIS

• We also illustrate how GIS tools can be used to analyze and interpret user data using an example of asthma epidemiology

Geographical Information System (GIS)

• What is GIS?– GIS is a computerized system for input, storage,

management, display, and analysis of data that can be precisely linked to a geographical location

• GIS datasets come as layers:– a layer for roads– a layer for rivers– a layer for zip code boundary– all within a particular geographical boundary

Geographical Information System (GIS)

• A layer may consists of a vector or raster

• Raster data types are images

• Vectors data types are defined by points, lines and polygons (boundary)– Points: hospitals, parks, and fire hydrants– Lines: Roads, highways, and rivers– Polygon: Zip code, county, state, and country

• A layer may consist of many features

• Several layers are combined to create a map

Major Roads and highways of Texas

County Boundaries of Texas

Superimposed Roads with County Boundaries

Expanded View: City of Houston

Geographical Information System (GIS)

• All features in a layer are stored in a shapefile

• Each shapefile has more than one file types associated with it: – one for the primary feature (points, lines, etc.)– one for the geometrical coordinates of the

primary feature: (x, y) or (x1, y1 -- x2, y2) – one for the geographical coordinate system

(longitude, latitude)– all sharing the same filename

Geographical Information System (GIS)

Geographical Information System (GIS)

• Each GIS layer has two views:– a map view– a data view

• The map acts as visual representation of data

• The data view can be used to:– to create a smaller dataset or map– to combine with user data to create a new layer

(as long as there is a common attribute between the GIS data and the user data)

GIS Layer: Map View

Manhattan

Bronx

Brooklyn

11696

11385

10465

11413

11364

1143411208

11101

11357

11207

11367

1137711368

11365

11414

11378

10461

11215

11232

11432

10473

11354

11375

11358

11420

11422

11426

11203

11211

11362

11379

11355

11373

11361

11433

11222

1136011105

10460

11412

11423

11356

11427

11236

10469

1143511206

10474

11231

11212

11201

1046210457

11221

11233

11237

11239

11429

10464

11369

11411

11419

11226

11418

11417

10472

11213

11238

10451

10467

10456

10025

10454

11363

10452

10021

11216

11004

10453

11371

10027

10458

10002

11421

11374

11220

11225

10029 10035

11106

11205

10032

11218

10459

11436

11217

11428

11366

1137011103

11102

11372

10455

11416

10001

10019

10031

10468

10040

10009

10034

10474

10011

10023

10003

10016

10013

10035

10033

11415

11430

10014

10024

11251

10022

10128

10036

10475

10464

1001810017

11104

10026

10010

10039

10012

10007

10028

10030

10038

10037

10044

10464

10004

11219

10463

1000510280

10038

11234

10005

GIS Layer: Data View

Geographical Information System (GIS)

• Most commonly used GIS tool is ArcView from ESRI (Environmental Systems Research Institute)– It uses a geodatabase to store all features– Can be used as a desktop or multi-user database

• Many federal, state, and local government agencies publish GIS data in the ArcView’s shapefile format

• These files can be downloaded from the Web

Geographical Information System (GIS)

Asthma Epidemic: An Example

• Asthma became a public health concern, especially among children in the U.S.– About 17.3 million Americans have asthma– More than 5000 people die from asthma per year– Asthma prevalence among children (0-17 years)

increased by ~ 5% each year during 1980-1995– African Americans suffer more than Caucasians– Females suffer more than males

Asthma Epidemic: An Example

Applications of GIS: Spatial Distribution of Asthma

• Most of the asthma data come from hospitalization records or surveying a localized population

• These data do not contain any spatial or geographical coordinate, but use zip code

• However, they can be joined with a spatial dataset such as a zip code layer to create a asthma layer

• Zip code from the two datasets can be used as a join parameter

Asthma Study of New York City

• Asthma data came from a survey of middle- and high schools students in the NY City

• The students were in the age group of 15-18 years

• About 4300 datasets were collected in two years from various boroughs of the city

• Data were summarized by zip code, borough, gender, and race

• ArcView GIS software was used for maps

Results: Total and Gender

Asthma No Asthma Total Percent Asthma677 3569 4246 15.94

Gender Asthma No Asthma Total Percent AsthmaMale 312 1518 1830 17.05Female 365 2050 2415 15.11

Total 677 3568 4245 15.95

Asthma by Gender: Normalized to Total

Male

53%

Female

47%

Results by RaceRace Asthma No Asthma Total Percent AsthmaWhite 100 669 769 13.00Black 215 1038 1253 17.16Hispanic 163 670 833 19.57Asian 107 826 933 11.47Native American 6 13 19 31.58Multi-Ethnic 43 98 141 30.50Other 29 181 210 13.81

Total 663 3495 4158 15.95

Asthma by Race: Normalized to Total

Asian

8%

White

9%

Other

10% Black

13%

Hispanic

14%Native

American

24%

Multi-Ethnic

22%

Results by BoroughBorough Asthma No Asthma Total Percent AsthmaManhattan 247 1070 1317 18.75Bronx 67 363 430 15.58Queens 239 1415 1654 14.45Brooklyn 111 601 712 15.59Staten Island 3 18 21 14.29Long Island 10 102 112 8.93

Total 677 3569 4246 15.94

Asthma in New York Boroughs

15.58 14.45 15.59 14.29

8.93

18.75

0.00

5.00

10.00

15.00

20.00

Man

hatta

n

Bronx

Que

ens

Brook

lyn

State

n Isl

and

Long

Isla

nd

Boroughs

Per

cen

t A

sth

ma

Summarized Data by Zip Code

Zip Code Total Surveyed

Num Of Asthmatics

Percent Asthmatics

93015 358 31 8.66

11212 335 68 20.3

11373 288 17 5.9

10029 163 41 25.15

20002 103 15 14.56

10039 101 21 20.79

10027 99 13 13.13

11372 97 5 5.15

10030 88 13 14.77

10031 88 16 18.18

20019 87 22 25.29

10035 83 12 14.46

11758 82 7 8.54

Resultant Dataset After Join on Zip Code: New York City

New York City Zip Code Layer

Map View of Resultant Dataset: NY City

Manhattan

Bronx

Brooklyn

Resulting Map Displaying the Zip Codes Surveyed

Overlaying of Asthma and NY City Layers

Manhattan

Bronx

Brooklyn

7

76

4

6

79

8

95

9

6

6

0

7

0

7

6

9

7

0

5

10

15

0

27

0

14

0

9

13

0

9

429

5

110

4

12

5

13

15

8

8

4

21

10

17

33

10

28

8

27

12

1419

6

20

12

5

0

12

12

13

0

11

22

14

19

17

13

12

18

25 14

12

18

27

18

0

132011

18

13

28

17

25

31

17

14

14

15

1313

27

24

27

21

19

18

1518

13

New York City Poverty

Manhattan

Bronx

Brooklyn

0.00

9.36

12.08

6.89

4.27

4.37

8.68

4.93

4.21

10.11

7.33

29.68

26.98

33.28

13.18

7.85

5.89

19.51

8.48

5.07

7.57

3.74

6.25

11.18

4.47

14.08

32.52

13.40

22.42

3.30

8.49

9.09

12.93

6.31

6.28

8.53

13.32

41.68

12.78

13.59

23.54

14.98

5.72

11.04

41.68

7.13

11.97

11.98

4.01

46.22

49.57

23.58

35.38

17.427.63

12.65

6.28

42.82

37.18

37.59

40.80

27.11

2.184.99

3.10

13.49

10.42

18.77

8.05

9.18

29.95

26.55

21.08

40.90

18.07

45.32

16.59

54.50

6.49

45.92

6.08

28.57

46.04

7.79

34.08

32.58

28.83

22.82

17.20

37.94 46.37

15.70

30.90

31.98

17.37

0.00

49.54

10.56

21.13

9.06 100.00

11.62

20.66

13.25

50.63

37.31

9.28

19.39

8.59

8.47

13.89

0.00

33.71

30.81

30.51

25.81

49.57

10.59

13.21

5.77

11.08

16.76

6.61

46.37

7.01

29.34

15.57

7.13

9.34

20.88

6.36

42.43

4.73

14.38

44.01

34.83

17.46

10.95

43.88

25.26

28.52

7.13

17.37

6.88

25.20

13.71

3.8514.29

8.81

25.26

5.55

14.29

Comparison of Asthma and Poverty

Manhattan

Bronx

Brooklyn

0.00

9.36

12.08

6.89

4.27

4.37

8.68

4.93

4.21

10.11

7.33

29.68

26.98

33.28

13.18

7.85

5.89

19.51

8.48

5.07

7.57

3.74

6.25

11.18

4.47

14.08

32.52

13.40

22.42

3.30

8.49

9.09

12.93

6.31

6.28

8.53

13.32

41.68

12.78

13.59

23.54

14.98

5.72

11.04

41.68

7.13

11.97

11.98

4.01

46.22

49.57

23.58

35.38

17.427.63

12.65

6.28

42.82

37.18

37.59

40.80

27.11

2.184.99

3.10

13.49

10.42

18.77

8.05

9.18

29.95

26.55

21.08

40.90

18.07

45.32

16.59

54.50

6.49

45.92

6.08

28.57

46.04

7.79

34.08

32.58

28.83

22.82

17.20

37.94 46.37

15.70

30.90

31.98

17.37

0.00

49.54

10.56

21.13

9.06 100.00

11.62

20.66

13.25

50.63

37.31

9.28

19.39

8.59

8.47

13.89

0.00

33.71

30.81

30.51

25.81

49.57

10.59

13.21

5.77

11.08

16.76

6.61

46.37

7.01

29.34

15.57

7.13

9.34

20.88

6.36

42.43

4.73

14.38

44.01

34.83

17.46

10.95

43.88

25.26

28.52

7.13

17.37

6.88

25.20

13.71

3.8514.29

8.81

25.26

5.55

14.29

Manhattan

Bronx

Brooklyn

7

76

4

6

79

8

95

9

6

6

0

7

0

7

6

9

7

0

5

10

15

0

27

0

14

0

9

13

0

9

429

5

110

4

12

5

13

15

8

8

4

21

10

17

33

10

28

8

27

12

1419

6

20

12

5

0

12

12

13

0

11

22

14

19

17

13

12

18

25 14

12

18

27

18

0

132011

18

13

28

17

25

31

17

14

14

15

1313

27

24

27

21

19

18

1518

13

GIS in Business

• GIS can be used to: – Optimize sales territories and delivery route to

balance workload and minimize travel– Display sales forecasts utilizing customer

demographic trends– Business site selection utilizing customer

demographic trends – Evaluate business acquisition opportunities by

knowing business composition and consumer consumption patterns in the locality

Map Customer Locations

• Create a "pin map" of where your customers live

• Find out what parts of town you draw customers and where to advertise

Identify Your Trade Area • Map your customers to see

what your trade area is  • Compare your customers

with the market potential to see your market penetration

Target Your Advertising • Given your trade area,

and your customer profile, you can focus advertising to the places and media that are most likely to hit your target market

Business Geography: A New Discipline

• The combined use of computer-mapping, Internet, database technologies, and location-allocation modeling techniques will become a particularly important set of skills for many business students whose first jobs after graduation involve real estate, urban, demographic, retail, marketing, environmental, transportation, international trade or investment analyses.

• A new discipline called “Business Geography” is evolving in many business schools across the country

Conclusion

• We have provided a brief overview of a Geographical Information System

• GIS uses various layers to create a map and each layer has two views: a dataset and a map

• Most layers are available from local, state, and federal government agencies

• Asthma epidemiology is used as an example to illustrate how user data can be combined with GIS data and make further decisions for research or healthcare planning

• We have also highlighted on Business Geograhy, an evolving program in business schools